subject:"\[Emc\-users\] Encoders"

On Saturday 16 June 2018 21:40:08 jeremy youngs wrote:

> Gene, it was an inference I knew you would get, all those years
> working the dairy farm in upstate, I only cook with the real thing.
> Having lost my grandma,mom and my brother now type 2 I strive really
> hard to keep lean and sugar low. I gave up sodas, heavy drinking,
> breads and anything else with unnatural sugars in it. At 42, 6'1 and
> 175 I hope it helps. I think my heart will wipe me out first, 1 open
> heart surgery already logged. Heart is great it's the arteries and
> aortic aneurysm I fear will cause the long , unexpected and hopefully
> painless sleep.

I've had my own 10 minute warning buzzer, a pulmonary embolism 3 or 4 
years ago.  Not really related to me being a DM-II,  but I was taking a 
multi-vitamin that had lots of vitamin k in it, so now my daily 
pilltainer gets stocked with everything else but...

And 7.5 mg of warfarin just to make sure I'll bleed to death, but somehow 
I still clot and seal up in a couple minutes. I've had to check back in 
for a few bags of heperin a couple times since.

As far as cuts & bruises, I've outlived all my enemies but one, me.  At 
83, twice your age, and getting clumsy, because my legs are about worn 
out, I am my own worst enemy.

> Chris , oddly enough I didn't even check digikey, I just let the eBay
> rip. I'm getting consternated on this subject. I keep promising photos
> but in keeping up with the shop traffic and the 86 Chevy restoration
> and funding all of these neat things I haven't yet found the time.
> Alas the damage is done. These capacitors are screw mount so if I get
> the time between backhoe hose and 460 engine removal tomorrow I will
> post some pics . I am striving for a top performing machine and things
> keep working out do that should well happen.
> TTYL thanks guys.

We would appreciate some pix of this as it takes shape.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

Gene, it was an inference I knew you would get, all those years working the
dairy farm in upstate, I only cook with the real thing.
Having lost my grandma,mom and my brother now type 2 I strive really hard
to keep lean and sugar low. I gave up sodas, heavy drinking, breads and
anything else with unnatural sugars in it. At 42, 6'1 and 175 I hope it
helps. I think my heart will wipe me out first, 1 open heart surgery
already logged. Heart is great it's the arteries and aortic aneurysm I fear
will cause the long , unexpected and hopefully painless sleep.

Chris , oddly enough I didn't even check digikey, I just let the eBay rip.
I'm getting consternated on this subject. I keep promising photos but in
keeping up with the shop traffic and the 86 Chevy restoration and funding
all of these neat things I haven't yet found the time. Alas the damage is
done. These capacitors are screw mount so if I get the time between backhoe
hose and 460 engine removal tomorrow I will post some pics . I am striving
for a top performing machine and things keep working out do that should
well happen.
TTYL thanks guys.
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-16 Thread Chris Albertson

I followed the link and was shocked at the price.  Try Digikey.  They are
$0.83 and you get them fast as they are a US supplier.  Check the data
sheet to see if they work for you.

On Sat, Jun 16, 2018 at 11:49 AM jeremy youngs  wrote:

> Thank you Gene,
> eBay item # 302357383187
> These correct? If so I will get them coming.
>
> On Sat, Jun 16, 2018, 12:54 PM Gene Heskett  wrote:
>
> > On Saturday 16 June 2018 13:00:08 jeremy youngs wrote:
> >
> > > A quick Google, digikey and eBay search turned up nothing for an if357
> > > , or an irf 357 . Any other suggestions?
> >
> > Did I do a "typu"? Or is lower case confusing the issue. s/b an LF357. Or
> > if you want the most stable, highly tested version, an LF157. Check the
> > whole family, maybe a different member suits you better. Stabilization
> > networks commonly used with those old slow op-amps can be removed as a
> > general rule.
> >
> > > --
> > > Check out the vibrant tech community on one of the world's
> > > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> >
> >
> > --
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > Genes Web page 
> >
> >
> >
> --
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Saturday 16 June 2018 19:42:14 jeremy youngs wrote:

> On Sat, Jun 16, 2018, 5:53 PM Gene Heskett  
wrote:
> > On Saturday 16 June 2018 14:48:27 jeremy youngs wrote:
> > > Thank you Gene,
> > > eBay item # 302357383187
> > > These correct? If so I will get them coming.
> >
> > Thats 2 for 11 bucks, for that he ought to cover the postage.  But
> > yes, thats the one I had in mind.
>
> Ordered, thanks for your advice.
>
> As to the other subject, generating a tach signal, I think in torque
> mode and the 7i90 driving it I won't need to worry about it.
>
> Now if I could find a user manual for these Western servo design bpu
> s2 32/30 drives I could cook with oleo
>
>
Nah, I've been using coconut oil for several years now.  It adds a 
sweeter taste to my pork chops and fried eggs. And its lots healthier. 
And doesn't run my sugar up either.

I'm a DM-II diabetic. 
> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Sat, Jun 16, 2018, 5:53 PM Gene Heskett  wrote:

> On Saturday 16 June 2018 14:48:27 jeremy youngs wrote:
>
> > Thank you Gene,
> > eBay item # 302357383187
> > These correct? If so I will get them coming.
>
> Thats 2 for 11 bucks, for that he ought to cover the postage.  But yes,
> thats the one I had in mind.
>

Ordered, thanks for your advice.

As to the other subject, generating a tach signal, I think in torque mode
and the 7i90 driving it I won't need to worry about it.

Now if I could find a user manual for these Western servo design bpu s2
32/30 drives I could cook with oleo

>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Saturday 16 June 2018 14:48:27 jeremy youngs wrote:

> Thank you Gene,
> eBay item # 302357383187
> These correct? If so I will get them coming.

Thats 2 for 11 bucks, for that he ought to cover the postage.  But yes, 
thats the one I had in mind.

> On Sat, Jun 16, 2018, 12:54 PM Gene Heskett  
wrote:
> > On Saturday 16 June 2018 13:00:08 jeremy youngs wrote:
> > > A quick Google, digikey and eBay search turned up nothing for an
> > > if357 , or an irf 357 . Any other suggestions?
> >
> > Did I do a "typu"? Or is lower case confusing the issue. s/b an
> > LF357. Or if you want the most stable, highly tested version, an
> > LF157. Check the whole family, maybe a different member suits you
> > better. Stabilization networks commonly used with those old slow
> > op-amps can be removed as a general rule.
> >
> > > --
> > >  Check out the vibrant tech community on one of the
> > > world's most engaging tech sites, Slashdot.org!
> > > http://sdm.link/slashdot
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> > --
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > Genes Web page 
> >
> >
> > 
> >-- Check out the vibrant tech community on one of the world's
> > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Saturday 16 June 2018 14:06:51 Chris Albertson wrote:

> On Sat, Jun 16, 2018 at 1:23 AM Gene Heskett  
wrote:
> > On Friday 15 June 2018 23:53:03 Chris Albertson wrote:
> >
> >
> > By using pdm/pwm in the pwmgens. At 50 kilohertz, then integrating
> > that to get your analog voltage. But no not pass the raw signal thru
> > an opto-isolator, the control linearity will be destroyed.
>
> Why is that?  Let's assume you have onto-isolater that are fast enough
> for the signals.  It seems that at most they would introduce a delay.
>
Except the on delay is not the same as the off delay. Based on running 
the pwd at a high enough frequency to get smooth control in the first 
place.  Even a 1 kilohertz pwm is fast enough to demo the effect, and at 
1 kilohertz by the time its been smoothed to the analog equ, control 
bandwidth is in the toilet. Take the opto's  out of the circuit, and run 
the pwm at 50 kilohertz, and you've then got control bandwidth to throw 
away. At 50 kilohertz, a .01% duty cycle gets you 15 to 20 revs at the 
motor shaft. With the lag of the opto's added, running at 1 kilohertz, 
it may take 5% duty cycle just to wake up the motor. Haveing the opto's 
confusing the issue you don't need.

> I do agree that you don't need an opto-isolator for an optical
> encoder.

That depends on the encoders resolution and how fast its spinning. Take 
the opto's out, and bingo, linear encoder response to 100 kilohertz or 
more. With the opto's the signals got lost at 240 rpms at the spindle, 
and the spindle went wide open.  Now I can request 20 rpm in high gear, 
and I cannot stop the spindle by grabbing it.  Burn up my hand maybe.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

Thank you Gene,
eBay item # 302357383187
These correct? If so I will get them coming.

On Sat, Jun 16, 2018, 12:54 PM Gene Heskett  wrote:

> On Saturday 16 June 2018 13:00:08 jeremy youngs wrote:
>
> > A quick Google, digikey and eBay search turned up nothing for an if357
> > , or an irf 357 . Any other suggestions?
>
> Did I do a "typu"? Or is lower case confusing the issue. s/b an LF357. Or
> if you want the most stable, highly tested version, an LF157. Check the
> whole family, maybe a different member suits you better. Stabilization
> networks commonly used with those old slow op-amps can be removed as a
> general rule.
>
> > --
> > Check out the vibrant tech community on one of the world's
> > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
> --
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page 
>
>
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-16 Thread Eric Keller

he apparently searched for 'if' which isn't going to work

On Sat, Jun 16, 2018 at 1:53 PM, Gene Heskett  wrote:

> On Saturday 16 June 2018 13:00:08 jeremy youngs wrote:
>
> > A quick Google, digikey and eBay search turned up nothing for an if357
> > , or an irf 357 . Any other suggestions?
>
> Did I do a "typu"? Or is lower case confusing the issue. s/b an LF357. Or
> if you want the most stable, highly tested version, an LF157. Check the
> whole family, maybe a different member suits you better. Stabilization
> networks commonly used with those old slow op-amps can be removed as a
> general rule.
>
> > --
> > Check out the vibrant tech community on one of the world's
> > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
> --
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page 
>
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-16 Thread Chris Albertson

On Sat, Jun 16, 2018 at 1:23 AM Gene Heskett  wrote:

> On Friday 15 June 2018 23:53:03 Chris Albertson wrote:
>
>
> By using pdm/pwm in the pwmgens. At 50 kilohertz, then integrating that
> to get your analog voltage. But no not pass the raw signal thru an
> opto-isolator, the control linearity will be destroyed.


Why is that?  Let's assume you have onto-isolater that are fast enough for
the signals.  It seems that at most they would introduce a delay.

I do agree that you don't need an opto-isolator for an optical encoder.
-- 

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Saturday 16 June 2018 13:00:08 jeremy youngs wrote:

> A quick Google, digikey and eBay search turned up nothing for an if357
> , or an irf 357 . Any other suggestions?

Did I do a "typu"? Or is lower case confusing the issue. s/b an LF357. Or 
if you want the most stable, highly tested version, an LF157. Check the 
whole family, maybe a different member suits you better. Stabilization 
networks commonly used with those old slow op-amps can be removed as a 
general rule.

> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

A quick Google, digikey and eBay search turned up nothing for an if357 , or
an irf 357 . Any other suggestions?
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Sat, Jun 16, 2018, 3:23 AM Gene Heskett  wrote:

> On Friday 15 June 2018 23:53:03 Chris Albertson wrote:
>
> > On Fri, Jun 15, 2018 at 7:58 PM Gene Heskett 
> wrote:
> > > On Friday 15 June 2018 20:20:20 jeremy youngs wrote:
> > >
> > > Aerotech mentions
> > > using 741's (op-amps) but the gain of a 741 above 10 hz falls like a
> > > rock, and that leaves the nyquist phase v stability angles in doubt.
> >
> > If the paper suggests using a 741, then the paper is very old.
>
> That amazed me too, Chris. I was reading about 1960 technology.
>
> That pdf is from aerotech's own site, anybody can download it and read
> it. Were I to design a similar device today, I'd certainly use lf357's
>

If I do this will I have to balance the op amp or is it a simple
replacement?

 And check any electrolytic caps for old age, replacing as
> necessary.
>
> Offtopic sorta:
>
>
>
> <
> https://www.banggood.com/Transistor-Tester-ESR-Capacitance-Meter-Resistance-Inductance-Measuring-p-1044840.html?rmmds=search
> >
>
> I have one of these and a variable supply for reforming caps, built a few
> months ago to resurrect my wife's organ .
>
> If Jeremy got those used, they are probably takeouts from a 30 yo or
> older machine.
>

1993, pulled from working environment, I agree the 741 is ancient , and
will likely replace them and will test these caps. The power supplies were
worth what I gave for the drives.

>
> If you can, the simplest way is to connect the digital
> > encoder to the mesa card, let it keep the position count then use that
> > any way you wish, possible to create the analog output you want
>

I'm hoping to allow the mess card to do this and set torque mode to use the
4020 as a simple amplifier. Thanks for the reassurance this is a good idea.

> >
> By using pdm/pwm in the pwmgens. At 50 kilohertz, then integrating that
> to get your analog voltage. But no not pass the raw signal thru an
> opto-isolator, the control linearity will be destroyed. There are no
> such critters in the 7i90/7i42TA control, but there will be in common
> BoB's used with the 5i25's and such parport simulators.
>
> > I would not build an analog, op amp based digital rate the analog
> > output converter even with modern op amps.  That is not the best
> > solution in 2018.  A digital counter is the way to do.  It is easy to
> > make and as exact as you want.   But I think the existing FPGA based
> > hardware should be able to count and you'd not need to actually build
> > anything.
>
> I hope to avoid building. I'm really busy in the auto shop so it will be a
> week or two before theory hits action.
>


Indeed.  Its all in the .hal code today, no "parts" involved. I think
> what I would do is hook into the power supply's, disconnecting the old
> active stuff and use them to feed power to one of the pico systems
> pwm-servo's per axis controlled.



This is a high probability, as mentioned the power supplies were worth the
cost of admission.


The control bandwidth is fast enough
> that with a low resolution encoder.
>
The cui encoder is selectable, o have it at 1000 ppr as that's what the
optical encoder that still works on the other ametek is at , that and 2.3:1
timing belt drive should give great resolution.  I have the work flow to
purchase x axis balkscrews in the near future as well. When I get a chance
I'm going to get some photos of the recent goodies that have showed up.

Thanks for bouncing ideas guys.
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Friday 15 June 2018 23:53:03 Chris Albertson wrote:

> On Fri, Jun 15, 2018 at 7:58 PM Gene Heskett  
wrote:
> > On Friday 15 June 2018 20:20:20 jeremy youngs wrote:
> >
> > Aerotech mentions
> > using 741's (op-amps) but the gain of a 741 above 10 hz falls like a
> > rock, and that leaves the nyquist phase v stability angles in doubt.
>
> If the paper suggests using a 741, then the paper is very old. 

That amazed me too, Chris. I was reading about 1960 technology.

That pdf is from aerotech's own site, anybody can download it and read 
it. Were I to design a similar device today, I'd certainly use lf357's 
or better. Something with a speed approaching video usage. If I were to 
pick up some of them used, I'd certainly warm up the iron and change 
them. And check any electrolytic caps for old age, replacing as 
necessary.

Offtopic sorta:

I just went thru a $20 set of computer speakers using one of those $20 
banggood parts testers, and replaced 6 of the 11 caps in it, sounds 
great again.

The tester I used is similar to this device but only has one button:

Biggest usage problem is the zif socket, not very sturdy. But it measures 
ESR, the most important characteristic of a cap after its capacity in 
u-f.

Ontopic:

If Jeremy got those used, they are probably takeouts from a 30 yo or 
older machine, And likely needing repairs as I am discussing to restore 
the original performance. Even NOS, sitting on the shelf gathering dust 
all this time, they would be suspect.

> Today 
> you can of course buy better op amps.   And of course today a micro
> controller can precisely measure an qucoder at any speed from zero up
> to some MHz. If you can, the simplest way is to connect the digital
> encoder to the mesa card, let it keep the position count then use that
> any way you wish, possible to create the analog output you want
>
By using pdm/pwm in the pwmgens. At 50 kilohertz, then integrating that 
to get your analog voltage. But no not pass the raw signal thru an 
opto-isolator, the control linearity will be destroyed. There are no 
such critters in the 7i90/7i42TA control, but there will be in common 
BoB's used with the 5i25's and such parport simulators.

> I would not build an analog, op amp based digital rate the analog
> output converter even with modern op amps.  That is not the best
> solution in 2018.  A digital counter is the way to do.  It is easy to
> make and as exact as you want.   But I think the existing FPGA based
> hardware should be able to count and you'd not need to actually build
> anything.

Indeed.  Its all in the .hal code today, no "parts" involved. I think 
what I would do is hook into the power supply's, disconnecting the old 
active stuff and use them to feed power to one of the pico systems 
pwm-servo's per axis controlled. The control bandwidth is fast enough 
that with a low resolution encoders quantization noise, it rattles the 
gear lash making you think you need to tear the head down and replace 
its vfx quality bearings, because it sounds like every ball in them is 
square. With a 1000 line encoder on the motor, my machine runs at least 
30 db quieter.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-15 Thread Chris Albertson

On Fri, Jun 15, 2018 at 7:58 PM Gene Heskett  wrote:

> On Friday 15 June 2018 20:20:20 jeremy youngs wrote:
>
> Aerotech mentions
> using 741's (op-amps) but the gain of a 741 above 10 hz falls like a
> rock, and that leaves the nyquist phase v stability angles in doubt.

If the paper suggests using a 741, then the paper is very old.  Today you
can of course buy better op amps.   And of course today a micro controller
can precisely measure an qucoder at any speed from zero up to some MHz.
If you can, the simplest way is to connect the digital encoder to the mesa
card, let it keep the position count then use that any way you wish,
possible to create the analog output you want

I would not build an analog, op amp based digital rate the analog output
converter even with modern op amps.  That is not the best solution in
2018.  A digital counter is the way to do.  It is easy to make and as exact
as you want.   But I think the existing FPGA based hardware should be able
to count and you'd not need to actually build anything.
-- 

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-15 Thread Gene Heskett

On Friday 15 June 2018 20:20:20 jeremy youngs wrote:

> Always another hurdle . Lol. I abandoned the h bridge plan for now as
> I am lacking sufficient power supply. I have 2 aerotech 4020 linear
> drives . The issue is they need tachometer feedback and it appears
> though the drive isn't configured for armature feedback. So the
> question is, is there a readily available device to convert 1000 ppr
> to an analog signal @7v /1000 rpm ?
>
> The drive is configurable to torque mode, would it be easier to set
> drive in torque mode and tune servo in Linux CNC with 7i90 ?
> Thanks

Put a 1000 line encoder on the motor, and use the encoders in the 7i90 to 
do a position servo. The aerotech drive is line powered, 20 amps max, 40 
volts max. And it has inputs for an encoder, taking lcnc out of the 
circuit if you'd like. But I'd druther put the encoder into linuxcnc, 
and let it calculate the pwm or pdm drive needed for a position null. I 
think it would be more precise, and possibly faster. Aerotech mentions 
using 741's (op-amps) but the gain of a 741 above 10 hz falls like a 
rock, and that leaves the nyquist phase v stability angles in doubt.

I don't see a reason why, if the correct motors are used, that it cannot 
be made to work.

> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-15 Thread jeremy youngs

Gmail is queing my messages for some reason. I apologize if this double
posts.

Always another hurdle . Lol. I abandoned the h bridge plan for now as I am
> lacking sufficient power supply. I have 2 aerotech 4020 linear drives . The
> issue is they need tachometer feedback and it appears though the drive
> isn't configured for armature feedback. So the question is, is there a
> readily available device to convert 1000 ppr to an analog signal @7v /1000
> rpm ?
>
> The drive is configurable to torque mode, would it be easier to set drive
> in torque mode and tune servo in Linux CNC with 7i90 ?
> Thanks
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-15 Thread jeremy youngs

Always another hurdle . Lol. I abandoned the h bridge plan for now as I am
lacking sufficient power supply. I have 2 aerotech 4020 linear drives . The
issue is they need tachometer feedback and it appears though the drive
isn't configured for armature feedback. So the question is, is there a
readily available device to convert 1000 ppr to an analog signal @7v /1000
rpm ?

The drive is configurable to torque mode, would it be easier to set drive
in torque mode and tune servo in Linux CNC with 7i90 ?
Thanks
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-04 Thread Todd Zuercher

I've had a few servo motors who's encoders did not have an index wire, but the 
encoder had all of the index hardware populated, and simply adding the 
necessary wire to connect it enabled it.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: jeremy youngs [mailto:jcyoung...@gmail.com] 
Sent: Monday, June 04, 2018 12:05 AM
To: Enhanced Machine Controller (EMC) 
Subject: Re: [Emc-users] Encoders

>
> No Index??? Seems like it would be handy.


It appears to have an index slot in the glass plate , but not enough wires
樂樂樂


OTOH, for XYZ, not a hard and
> fast requirement as long as the home switches are good.


I have 5 of those inductive pickups we were talking about a few months back, I 
think Greg or Chris brought them to our attention , so we will find out.

But you'll need
> it on the spindle. In fact, the index is the only thing that must be 
> tied to the spindle if you ever want to do rigid tapping.
> I'm gonna put one of thousands cui encoders on it, I left this renco 
> on the ametek as I'm just plain lazy and figured with the home 
> switches it wasn't absolutely essential to have index.
>
Also without this new motor in hand I have no idea how it is equipped , 
hopefully it already has a nice encoder on it 

>
> The rest of the encoder (a/b signals) can be on the motor, and you can 
> calibrate the scale for the spindle with some hal stuff you can 
> comment back out of the hal file once the scale has been determined. 
> Thats how I did mine anyway. Works a treat.
>

I'm sure I will have questions for this.

>
> > Finally, something that didn't fight me tooth and nail.
>
> > Now I have to put an encoder on the z motor and wait for brown to 
> > drop this 6hp spindle motor off and see what I need for that, I have 
> > 2 drives coming for that and a bid on a power supply for the drives 
> > so life is well at this time.
>
> Sounds good. How much weight do have to man handle on the Z?
>
This motor ships at 50 lbs it's a knee mill , however it only has freedom of 
movement along the x axis , I hope to turn this later with a harmonic drive

>
> > Ttyl take care fellas
>
> We try. I've got the tap hat g-code working well, but ran out of M6 
> grub screws, so I just ordered another 100 M6's and 100 M8's for the 
> biggest taps, which should run me out of brass before I run out of 
> taps to mount. So sometime after the screws get here, I should order 
> another 6 feet of 7/8" brass rod.  And a decent set of letter drills, 
> these are only slightly better than cold butter. Even running each one 
> thru one of the original drill doctors isn't enough to drill clean in 
> one pass. In brass.
>
> Good to hear you're making progress as well.
> --
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
>
>
> --
>  Check out the vibrant tech community on one of the world's 
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most engaging tech 
sites, Slashdot.org! http://sdm.link/slashdot 
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-03 Thread jeremy youngs

>
> No Index??? Seems like it would be handy.


It appears to have an index slot in the glass plate , but not enough wires
樂樂樂


OTOH, for XYZ, not a hard and
> fast requirement as long as the home switches are good.


I have 5 of those inductive pickups we were talking about a few months
back, I think Greg or Chris brought them to our attention , so we will find
out.

But you'll need
> it on the spindle. In fact, the index is the only thing that must be
> tied to the spindle if you ever want to do rigid tapping.
> I'm gonna put one of thousands cui encoders on it, I left this renco on
> the ametek as I'm just plain lazy and figured with the home switches it
> wasn't absolutely essential to have index.
>
Also without this new motor in hand I have no idea how it is equipped ,
hopefully it already has a nice encoder on it 

>
> The rest of the encoder (a/b signals) can be on the motor, and you can
> calibrate the scale for the spindle with some hal stuff you can comment
> back out of the hal file once the scale has been determined. Thats how I
> did mine anyway. Works a treat.
>

I'm sure I will have questions for this.

>
> > Finally, something that didn't fight me tooth and nail.
>
> > Now I have to put an encoder on the z motor and wait for brown to drop
> > this 6hp spindle motor off and see what I need for that, I have 2
> > drives coming for that and a bid on a power supply for the drives so
> > life is well at this time.
>
> Sounds good. How much weight do have to man handle on the Z?
>
This motor ships at 50 lbs it's a knee mill , however it only has freedom
of movement along the x axis , I hope to turn this later with a harmonic
drive

>
> > Ttyl take care fellas
>
> We try. I've got the tap hat g-code working well, but ran out of M6 grub
> screws, so I just ordered another 100 M6's and 100 M8's for the biggest
> taps, which should run me out of brass before I run out of taps to
> mount. So sometime after the screws get here, I should order another 6
> feet of 7/8" brass rod.  And a decent set of letter drills, these are
> only slightly better than cold butter. Even running each one thru one of
> the original drill doctors isn't enough to drill clean in one pass. In
> brass.
>
> Good to hear you're making progress as well.
> --
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page 
>
>
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-03 Thread Gene Heskett

On Sunday 03 June 2018 22:31:32 jeremy youngs wrote:

> Update, I pulled this other ametek motor apart. And it had a glass
> disc encoder, only 4 wires and clearly labeled a,b,5, gnd , so no
> blown opto when I hooked it up. The glass disc said 1000 on it so I'm
> presuming it's a 1000 PPR encoder, I will check part numbers tomorrow
> . Hooked it to 7i90 and it just works.

No Index??? Seems like it would be handy. OTOH, for XYZ, not a hard and 
fast requirement as long as the home switches are good. But you'll need 
it on the spindle. In fact, the index is the only thing that must be 
tied to the spindle if you ever want to do rigid tapping.

The rest of the encoder (a/b signals) can be on the motor, and you can 
calibrate the scale for the spindle with some hal stuff you can comment 
back out of the hal file once the scale has been determined. Thats how I 
did mine anyway. Works a treat.

> Finally, something that didn't fight me tooth and nail.

> Now I have to put an encoder on the z motor and wait for brown to drop
> this 6hp spindle motor off and see what I need for that, I have 2
> drives coming for that and a bid on a power supply for the drives so
> life is well at this time.

Sounds good. How much weight do have to man handle on the Z?

> Ttyl take care fellas

We try. I've got the tap hat g-code working well, but ran out of M6 grub 
screws, so I just ordered another 100 M6's and 100 M8's for the biggest 
taps, which should run me out of brass before I run out of taps to 
mount. So sometime after the screws get here, I should order another 6 
feet of 7/8" brass rod.  And a decent set of letter drills, these are 
only slightly better than cold butter. Even running each one thru one of 
the original drill doctors isn't enough to drill clean in one pass. In 
brass.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-03 Thread jeremy youngs

Update, I pulled this other ametek motor apart. And it had a glass disc
encoder, only 4 wires and clearly labeled a,b,5, gnd , so no blown opto
when I hooked it up. The glass disc said 1000 on it so I'm presuming it's a
1000 PPR encoder, I will check part numbers tomorrow . Hooked it to 7i90
and it just works.
Finally, something that didn't fight me tooth and nail.
Now I have to put an encoder on the z motor and wait for brown to drop this
6hp spindle motor off and see what I need for that, I have 2 drives coming
for that and a bid on a power supply for the drives so life is well at this
time.
Ttyl take care fellas
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-01 Thread Chris Albertson

Yes, they have Mac, Linux and Windows version of the software.  Closed
source but free from Saleae.  The $8 clone is just a tiny uP that reads 8
input pins really fast and puts the data on USB.   Al the smarts is in the
software.

Saleae makes some really nice ones that use the same software but have more
pins and faster pins and can handle more different voltage levels.

One thing that modern logic analyzers can do that scope can't is trigger on
data.




Sigrok looks good but I don't use it much, just checked it out a little.
The Saleae software is so easy to use you don't need a user manual.



On Fri, Jun 1, 2018 at 10:52 AM, Gene Heskett  wrote:

> On Friday 01 June 2018 12:32:09 Chris Albertson wrote:
>
> > On Thu, May 31, 2018 at 5:38 PM, Gene Heskett 
> wrote:
> > > On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:
> > > > Encoders in hand, shaft turned and mounted, it looks good, 3 more
> > > > to do . encoderawcount.jpg
> > > >  > > >/vie w?usp=drivesdk>
> > >
> > > That does look pretty good at first glance. I can't read the
> > > clocking rate though. Humm, I just found the viewer has a zoom. So I
> > > assume you were turning it by hand as the timing shows 2/1
> > > variations on a 10 millisecond per grid line, so thats pretty slow.
> > > What it looks like at 3 to 5k revs will tell the story. But you are
> > > not going to get that display at 3 to 5k in halscope. That will need
> > > a good scope,
> >
> > Scopes are good, they will let yu find glitches like housing contacts
> > but optical encoders don't have that problem
> >
> > Last night I was using by cheap $8 logic analyzer.   Those things are
> > good for the money I could measure the duty cycle of a  two 10KHz PWM
> > signals and the A/B channels for two encoders and
> > ...ebay.com/itm/New-USB-Logic-Analyzer-...
> >  >24MHz-8CH-24MHz-for-ARM-FPGA-M100/222882469206>
> >
> > Yes they make better ones but those cost more than $8   This is one
> > good for signals that change at up to a few MHz.
> >
> I'd have to assume it displays the results on your computer screen, and
> runs on linux?
>
> Rather neat if thats the case, I might have to get me one.
>
> Thanks Chris.
>
> > > --
> >
> > Chris Albertson
> > Redondo Beach, California
> > --
> > Check out the vibrant tech community on one of the world's
> > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
> --
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page 
>
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>



-- 

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-01 Thread Chris Albertson

The device is a clone of the Saleae analyzer so it works with their software
https://www.saleae.com/downloads/

There is also some open source software that works with it
https://sigrok.org/wiki/Main_Page

On Fri, Jun 1, 2018 at 9:40 AM, Greg Bernard  wrote:

> Interesting. What software do you use with that?
>
>
> On Fri, Jun 1, 2018 at 11:32 AM, Chris Albertson <
> albertson.ch...@gmail.com>
> wrote:
>
> > On Thu, May 31, 2018 at 5:38 PM, Gene Heskett 
> > wrote:
> >
> > > On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:
> > >
> > > > Encoders in hand, shaft turned and mounted, it looks good, 3 more to
> > > > do . encoderawcount.jpg
> > > >  ZzVBCtBkDbsFxwydN_/vie
> > > >w?usp=drivesdk>
> > >
> > > That does look pretty good at first glance. I can't read the clocking
> > > rate though. Humm, I just found the viewer has a zoom. So I assume you
> > > were turning it by hand as the timing shows 2/1 variations on a 10
> > > millisecond per grid line, so thats pretty slow. What it looks like at
> 3
> > > to 5k revs will tell the story. But you are not going to get that
> > > display at 3 to 5k in halscope. That will need a good scope,
> > >
> >
> > Scopes are good, they will let yu find glitches like housing contacts but
> > optical encoders don't have that problem
> >
> > Last night I was using by cheap $8 logic analyzer.   Those things are
> good
> > for the money I could measure the duty cycle of a  two 10KHz PWM signals
> > and the A/B channels for two encoders and
> > ...ebay.com/itm/New-USB-Logic-Analyzer-...
> >  > USB-Cable-24MHz-8CH-24MHz-for-ARM-FPGA-M100/222882469206>
> >
> > Yes they make better ones but those cost more than $8   This is one good
> > for signals that change at up to a few MHz.
> >
> >
> > >
> > > --
> >
> > Chris Albertson
> > Redondo Beach, California
> > 
> > --
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
>
>
> --
> "Anyone who believes exponential growth can go on forever in a finite world
> is either a madman or an economist."
> -Kenneth Boulding, economist
> Corporations are NOT people and money is NOT speech!
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>



-- 

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-01 Thread Gene Heskett

On Friday 01 June 2018 12:32:09 Chris Albertson wrote:

> On Thu, May 31, 2018 at 5:38 PM, Gene Heskett  
wrote:
> > On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:
> > > Encoders in hand, shaft turned and mounted, it looks good, 3 more
> > > to do . encoderawcount.jpg
> > >  > >/vie w?usp=drivesdk>
> >
> > That does look pretty good at first glance. I can't read the
> > clocking rate though. Humm, I just found the viewer has a zoom. So I
> > assume you were turning it by hand as the timing shows 2/1
> > variations on a 10 millisecond per grid line, so thats pretty slow.
> > What it looks like at 3 to 5k revs will tell the story. But you are
> > not going to get that display at 3 to 5k in halscope. That will need
> > a good scope,
>
> Scopes are good, they will let yu find glitches like housing contacts
> but optical encoders don't have that problem
>
> Last night I was using by cheap $8 logic analyzer.   Those things are
> good for the money I could measure the duty cycle of a  two 10KHz PWM
> signals and the A/B channels for two encoders and
> ...ebay.com/itm/New-USB-Logic-Analyzer-...
> 24MHz-8CH-24MHz-for-ARM-FPGA-M100/222882469206>
>
> Yes they make better ones but those cost more than $8   This is one
> good for signals that change at up to a few MHz.
>
I'd have to assume it displays the results on your computer screen, and 
runs on linux?

Rather neat if thats the case, I might have to get me one.

Thanks Chris.

> > --
>
> Chris Albertson
> Redondo Beach, California
> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-01 Thread Greg Bernard

Interesting. What software do you use with that?


On Fri, Jun 1, 2018 at 11:32 AM, Chris Albertson 
wrote:

> On Thu, May 31, 2018 at 5:38 PM, Gene Heskett 
> wrote:
>
> > On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:
> >
> > > Encoders in hand, shaft turned and mounted, it looks good, 3 more to
> > > do . encoderawcount.jpg
> > >  > >w?usp=drivesdk>
> >
> > That does look pretty good at first glance. I can't read the clocking
> > rate though. Humm, I just found the viewer has a zoom. So I assume you
> > were turning it by hand as the timing shows 2/1 variations on a 10
> > millisecond per grid line, so thats pretty slow. What it looks like at 3
> > to 5k revs will tell the story. But you are not going to get that
> > display at 3 to 5k in halscope. That will need a good scope,
> >
>
> Scopes are good, they will let yu find glitches like housing contacts but
> optical encoders don't have that problem
>
> Last night I was using by cheap $8 logic analyzer.   Those things are good
> for the money I could measure the duty cycle of a  two 10KHz PWM signals
> and the A/B channels for two encoders and
> ...ebay.com/itm/New-USB-Logic-Analyzer-...
>  USB-Cable-24MHz-8CH-24MHz-for-ARM-FPGA-M100/222882469206>
>
> Yes they make better ones but those cost more than $8   This is one good
> for signals that change at up to a few MHz.
>
>
> >
> > --
>
> Chris Albertson
> Redondo Beach, California
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>



-- 
"Anyone who believes exponential growth can go on forever in a finite world
is either a madman or an economist."
-Kenneth Boulding, economist
Corporations are NOT people and money is NOT speech!
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-06-01 Thread Chris Albertson

On Thu, May 31, 2018 at 5:38 PM, Gene Heskett  wrote:

> On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:
>
> > Encoders in hand, shaft turned and mounted, it looks good, 3 more to
> > do . encoderawcount.jpg
> >  >w?usp=drivesdk>
>
> That does look pretty good at first glance. I can't read the clocking
> rate though. Humm, I just found the viewer has a zoom. So I assume you
> were turning it by hand as the timing shows 2/1 variations on a 10
> millisecond per grid line, so thats pretty slow. What it looks like at 3
> to 5k revs will tell the story. But you are not going to get that
> display at 3 to 5k in halscope. That will need a good scope,
>

Scopes are good, they will let yu find glitches like housing contacts but
optical encoders don't have that problem

Last night I was using by cheap $8 logic analyzer.   Those things are good
for the money I could measure the duty cycle of a  two 10KHz PWM signals
and the A/B channels for two encoders and
...ebay.com/itm/New-USB-Logic-Analyzer-...


Yes they make better ones but those cost more than $8   This is one good
for signals that change at up to a few MHz.


>
> --

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-31 Thread Gene Heskett

On Thursday 31 May 2018 21:58:49 jeremy youngs wrote:

> On Thu, May 31, 2018, 19:39 Gene Heskett  wrote:
> > On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:
> > > Encoders in hand, shaft turned and mounted, it looks good, 3 more
> > > to do . encoderawcount.jpg
> > >  > >/vie w?usp=drivesdk>
> >
> > That does look pretty good at first glance. I can't read the
> > clocking rate though. Humm, I just found the viewer has a zoom. So I
> > assume you were turning it by hand as the timing shows 2/1
> > variations on a 10
>
> Back emf , as measured in lathe at 800 rpm was 21.6 volts. It's a 20
> volt motor , I intend on driving at 28 volts with generic hbridge. I'm
> not sure that 28 will give the 300 ipm rapid I'm after, but time will
> tell. I was powering this with a 700 ma 5 volt supply so motor speed
> was pretty slow, I did not put my tach on it , encoders are set to
> 1000 PPR as that's what I already have the 7i 90 programmed to. 20/56
> is the timing pulley ratio so that will be over 2k per rev. I hope to
> ballscrew the x in the next month or so , y and z are already
> ballscrew although I think I am going to replace the y screw ( again)
> as it's a surplus screw and I don't like it's mount and have been
> fairly impressed with the Chinese screw I put in z.
>
>
>
>
> millisecond per grid line, so thats pretty slow. What it looks like at
> 3
>
> > to 5k revs will tell the story.
>
> I'm pretty sure 2k will be the absolute max with my setup.
>
>
> But you are not going to get that
>
> > display at 3 to 5k in halscope. That will need a good scope,
> >
> > On the list, but concrete and shop expansion are essential at this
> > time . I wrench to support my Machine habit 
> >
Humm, there's a quite similar echo in here, except I'm now retired for 
about 16 years.  So I wrench to keep me out of the bars. Actually dead 
tired tonight, taking care of the missus. We've decided to leave town 
next February, so maybe she won't fall and break something 3 years in a 
row. Went in for some xrays to see how the leg is healed, looks great. 
Now it needs meat. I've got to tie her down when the wind comes up.  But 
COPD never lets up and this ultra humid weather isn't doing that any 
good at all.

I did get 2 more tap hats completed this morning though, 15 done now. 
About 30 & change to go.  Now using some of those I've already made, 
after making my code automatically adjust for tool length, I spend more 
time finding the correct drill sizes (and sharpening them in a drill 
doctor) than in the actual machining.

-- 
Cheers Jeremy, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-31 Thread jeremy youngs

On Thu, May 31, 2018, 19:39 Gene Heskett  wrote:

> On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:
>
> > Encoders in hand, shaft turned and mounted, it looks good, 3 more to
> > do . encoderawcount.jpg
> >  >w?usp=drivesdk>
>
> That does look pretty good at first glance. I can't read the clocking
> rate though. Humm, I just found the viewer has a zoom. So I assume you
> were turning it by hand as the timing shows 2/1 variations on a 10
>

Back emf , as measured in lathe at 800 rpm was 21.6 volts. It's a 20 volt
motor , I intend on driving at 28 volts with generic hbridge. I'm not sure
that 28 will give the 300 ipm rapid I'm after, but time will tell. I was
powering this with a 700 ma 5 volt supply so motor speed was pretty slow, I
did not put my tach on it , encoders are set to 1000 PPR as that's what I
already have the 7i 90 programmed to. 20/56 is the timing pulley ratio so
that will be over 2k per rev. I hope to ballscrew the x in the next month
or so , y and z are already ballscrew although I think I am going to
replace the y screw ( again) as it's a surplus screw and I don't like it's
mount and have been fairly impressed with the Chinese screw I put in z.

millisecond per grid line, so thats pretty slow. What it looks like at 3
> to 5k revs will tell the story.

I'm pretty sure 2k will be the absolute max with my setup.

But you are not going to get that
> display at 3 to 5k in halscope. That will need a good scope,
>
> On the list, but concrete and shop expansion are essential at this time .
> I wrench to support my Machine habit 
>
> > --
> > Check out the vibrant tech community on one of the world's
> > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
> --
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page 
>
>
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-31 Thread Gene Heskett

On Thursday 31 May 2018 19:45:24 jeremy youngs wrote:

> Encoders in hand, shaft turned and mounted, it looks good, 3 more to
> do . encoderawcount.jpg
> w?usp=drivesdk>

That does look pretty good at first glance. I can't read the clocking 
rate though. Humm, I just found the viewer has a zoom. So I assume you 
were turning it by hand as the timing shows 2/1 variations on a 10 
millisecond per grid line, so thats pretty slow. What it looks like at 3 
to 5k revs will tell the story. But you are not going to get that 
display at 3 to 5k in halscope. That will need a good scope,

> --
> Check out the vibrant tech community on one of the world's
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-31 Thread jeremy youngs

A,b and index. I'm beat for the day , I will follow up tomorrow, been
really busy in shop, beginning an ls swap and restoration of an 83 3/4 ton
Chevy for a customer. That will limit my ability to get this done , but
will provide much needed funds.

Also, I won the bid on that 6 horse bldc 37 NM motor, I will have questions
> about that when the brown dude drops it off.
>

Also I had the horizontal zoom up Fairly high, don't know if that makes a
difference. Can you post a pic of a good waveform please ?

>
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-31 Thread andy pugh

On 1 June 2018 at 00:45, jeremy youngs  wrote:
> Encoders in hand, shaft turned and mounted, it looks good, 3 more to do .
>   encoderawcount.jpg
> 

Is that with only one channel connected? Rawcounts should increase,
not go 1,0,1,0


-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-31 Thread jeremy youngs

Encoders in hand, shaft turned and mounted, it looks good, 3 more to do .
  encoderawcount.jpg

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread Chris Albertson

On Sat, May 26, 2018 at 9:23 AM, Jon Elson  wrote:
> On 05/26/2018 10:54 AM, Chris Albertson wrote:
>>
>> I had to look up the link to see how it is possible for an encoder to
>> cause lag.   Only by not having enough resolution for low speed
>> operations
>>
> The AMT encoders use interpolation of a very low resolution basic sensor.
> They must have some kind of velocity tracking loop.  When velocity changes
> suddenly, the position of the tracking loop falls behind the actual
> position, and the loop is commanded to speed up.

Looks like I guested right, low resolution encoders require a long
sample period to avoid quantization error.

There is a solution.  You stop COUNTING encoder ticks and measure the
TIME between the ticks.  But this requires an encoder that gives acce
to the actual edges of the physical encoder disk.



-- 

Chris Albertson
Redondo Beach, California

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread Jon Elson


On 05/26/2018 10:54 AM, Chris Albertson wrote:

I had to look up the link to see how it is possible for an encoder to
cause lag.   Only by not having enough resolution for low speed
operations

The AMT encoders use interpolation of a very low resolution 
basic sensor.  They must have some kind of velocity tracking 
loop.  When velocity changes suddenly, the position of the 
tracking loop falls behind the actual position, and the loop 
is commanded to speed up.


Jon

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread jeremy youngs

On Sat, May 26, 2018, 10:54 Chris Albertson 
wrote:

> I had to look up the link to see how it is possible for an encoder to
> cause lag.   Only by not having enough resolution for low speed
> operations
>
> Did you notice the 20 week lead time and the note about problems at the
> factory?
>

I didn't see factory problems, but digikey has hundreds in stock, and they
are already in the box headed this way, we will see next week rather I am
smiling or crying lol

>
>
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread Chris Albertson

I had to look up the link to see how it is possible for an encoder to
cause lag.   Only by not having enough resolution for low speed
operations

Did you notice the 20 week lead time and the note about problems at the factory?

On Sat, May 26, 2018 at 4:40 AM, andy pugh  wrote:
> On 25 May 2018 at 07:24, jeremy youngs  wrote:
>
>> https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d
>> Any thoughts? Seems like a good solution
>
> I was expecting Jon Elson to chip in. I think he found an odd
> accelleration lag with these encoders:
>
> https://sourceforge.net/p/emc/mailman/emc-developers/thread/4DFC13BB.4020109%40pico-systems.com/#msg27669457
>
> --
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1916
>
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



-- 

Chris Albertson
Redondo Beach, California

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread Jon Elson

On 05/26/2018 06:40 AM, andy pugh wrote:

On 25 May 2018 at 07:24, jeremy youngs wrote:

https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d
Any thoughts? Seems like a good solution

I was expecting Jon Elson to chip in. I think he found an odd
accelleration lag with these encoders:

https://sourceforge.net/p/emc/mailman/emc-developers/thread/4DFC13BB.4020109%40pico-systems.com/#msg27669457

Yes, but it may not be as big a deal as I once thought.
Certainly, a lot of people have used them with Gecko 320
drives. But, yes, I rigged a motor to both an AMT103 and a
HEDS optical encoder, and fed both into encoder channels on
my PWM controller, so I could compare them sample by sample.
And, I did find a couple ms lag in response to
acceleration. Then, the AMT103 would show greater velocity
for a bit so the position could catch up.

So, it may depend a lot on the bandwidth of your servo loops
as to whether it causes any stability problems.

These encoders are CERTAINLY some of the least expensive
available. There is a little issue where the sensing rotor
can be a loose fit on the collet that fits over the shaft.
You really do NOT want the rotor to be able to rattle
around. Mariss Freimanis of Geckodrive suggests supergluing
the rotor in place.

Jon

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread Gene Heskett

On Saturday 26 May 2018 07:40:05 andy pugh wrote:

> On 25 May 2018 at 07:24, jeremy youngs  wrote:
> > https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46
> >O%252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d Any thoughts? Seems like
> > a good solution
>
> I was expecting Jon Elson to chip in. I think he found an odd
> accelleration lag with these encoders:
>
> https://sourceforge.net/p/emc/mailman/emc-developers/thread/4DFC13BB.4
>020109%40pico-systems.com/#msg27669457

I vaguely remember that thread, 2-4 years ago, thank you for the reminder 
and link. All of my home-made efforts have been magnetic (ats667's in 
the sheldon lathe watching its 60 tooth main gear, but no PID's, just 
feedback for rigid tapping), or opto-interrupters in the others. This 
Omron was not mentioned in that thread, perhaps its newer? But it seems 
to be far smoother at controlling a motor, so much so that on the mill, 
I have used Pgains of 40 in its PID, whereas with the combined 
mechanical errors and such of the home made opticals, Pgain was very 
limited, 3 maximum, and even then the quantization noise was hammering 
the gear teeth in the g0704's head, making it sound like every bearing 
in the head was hammered flat. The difference in the noise level when 
running is amazing. Below 500 rpms, I have to look at the spindle nose 
or tool to verify its running, its that quiet.

Its self contained, so I have no clue what technology is used internally, 
and its just over a $20 bill on ebay. Perhaps someone could do similar 
tests on one of those. I am, for just small change, very impressed with 
the single such device I have.  Its made a whole new machine out of a 
noisy rattle-trap. But because it is not on the spindle, its on the back 
of the motor, I am using only its a/b outputs, the index is still coming 
from the home-made opto-interruptor that is on the spindle.

off-topic bragging, I have some switches on the gearshift knob and some 
hal magic to correct for the gear changes of coarse. And I made use of 
that to add a setp to the neither switch closed state so the motor is 
turning at about 20 rpm's when the gear is in neutral but is supposed to 
be running. I can reach up and change gears at 1400 revs, its down to 
about 20 motor shaft rpm's long before the gear is disengaged, and 
because the motor is turning, the next gear engages silently, bringing 
the motor back to selected speed when the switch closes, indicating full 
engagement. None of the grab the spindle and turn it by hand coaxing the 
gears to re-engage.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread jeremy youngs

On Sat, May 26, 2018, 06:41 andy pugh  wrote:

> On 25 May 2018 at 07:24, jeremy youngs  wrote:
>
> >
> https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d
> > Any thoughts? Seems like a good solution
>
> I was expecting Jon Elson to chip in. I think he found an odd
> accelleration lag with these encoders:
>
>
> https://sourceforge.net/p/emc/mailman/emc-developers/thread/4DFC13BB.4020109%40pico-systems.com/#msg27669457
>
>
> Maybe I should have been more patient, but they are on their way , and I'm
> soon to find out.
> --
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1916
>
>
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-26 Thread andy pugh

On 25 May 2018 at 07:24, jeremy youngs  wrote:

> https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d
> Any thoughts? Seems like a good solution

I was expecting Jon Elson to chip in. I think he found an odd
accelleration lag with these encoders:

https://sourceforge.net/p/emc/mailman/emc-developers/thread/4DFC13BB.4020109%40pico-systems.com/#msg27669457

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-25 Thread jeremy youngs

These will be here late next week
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-25 Thread jeremy youngs

On Fri, May 25, 2018, 07:01 Gene Heskett  wrote:

> On Friday 25 May 2018 02:24:57 jeremy youngs wrote:
>
> > New thread, as I seem to be done getting the 7i90 functional.
> > These are capacitive and seem to have good response, universal and
> > programmable. And cheap and u.s. stock, 15.3 mm is the largest of them
> > I can find, and I don't understand what they say about axial or radial
> > mount . I will call them tomorrow .
> >
> > https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%
> >252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d Any thoughts? Seems like a
> > good solution , for a stocking part a fella could even keep a couple
> > to gather dust .
>
> Thats about the same price as the Omron, and it uses the motors bearings
> and fits the tailshaft, so it mounts much more compactly than the Omron.
> But the Omron has its own bearings making it totally selfcontained. But
> in close proximity to the motors magnetic field, the index may not work.
> And they are out of stock till the 2nd week of June, more delay than
> ebay/omron, by a week maybe.
>
> Digikey has them in stock, I gave the wrong link , I'm going to pull the
> trigger on this as it's easier to modify my shaft if necessary than it is
> to adapt the omron, I will give report when I get them.
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-25 Thread Gene Heskett

On Friday 25 May 2018 02:24:57 jeremy youngs wrote:

> New thread, as I seem to be done getting the 7i90 functional.
> These are capacitive and seem to have good response, universal and
> programmable. And cheap and u.s. stock, 15.3 mm is the largest of them
> I can find, and I don't understand what they say about axial or radial
> mount . I will call them tomorrow .
>
> https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%
>252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d Any thoughts? Seems like a
> good solution , for a stocking part a fella could even keep a couple
> to gather dust .

Thats about the same price as the Omron, and it uses the motors bearings 
and fits the tailshaft, so it mounts much more compactly than the Omron. 
But the Omron has its own bearings making it totally selfcontained. But 
in close proximity to the motors magnetic field, the index may not work. 
And they are out of stock till the 2nd week of June, more delay than 
ebay/omron, by a week maybe.

It says stepper magnetics, but I don't see a huge diff between the 
magnetic noise of a chopper current regulated stepper, or the magnetic 
noise of a pwm driven servo.  There will be an ultrasonic component to 
either's magnetic field. Interesting connundrum. If motors came 
predrilled, the choice is the CUA, but they don't.

As for deleting portions of the text that are not germane to the reply, 
in kmail, use the arrows keys to place the cursor where you want to 
start deleting, step on the shift key and using the arrow keys, 
highlight whats to go and hit the delete key. Its gone. kmail also has 
an undo function in case that wasn't what you intended to do.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2018-05-25 Thread Chris Kelley

>From looking at the mechanical drawings on the datasheet, it looks like the
axial/radial mount refers to the direction of the connector pins.

On Fri, May 25, 2018 at 1:24 AM, jeremy youngs  wrote:

> New thread, as I seem to be done getting the 7i90 functional.
> These are capacitive and seem to have good response, universal and
> programmable. And cheap and u.s. stock, 15.3 mm is the largest of them I
> can find, and I don't understand what they say about axial or radial mount
> . I will call them tomorrow .
>
> https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%
> 252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d
> Any thoughts? Seems like a good solution , for a stocking part a fella
> could even keep a couple to gather dust .
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Encoders

2018-05-25 Thread jeremy youngs

New thread, as I seem to be done getting the 7i90 functional.
These are capacitive and seem to have good response, universal and
programmable. And cheap and u.s. stock, 15.3 mm is the largest of them I
can find, and I don't understand what they say about axial or radial mount
. I will call them tomorrow .

https://www.mouser.com/ProductDetail/CUI/AMT103-V?qs=sGAEpiMZZMsWp46O%252bq11Wc6D0rLp%252bQH%2fN7GEqDkL%2fc8%3d
Any thoughts? Seems like a good solution , for a stocking part a fella
could even keep a couple to gather dust .
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Encoders

2018-05-14 Thread jeremy youngs

Hi all. These ametek motors have undefined encoders on them. One is just an
empty 4 pin. The other has a flat 4 pin ribbon. I'm awaiting my 7i42 . The
flat ribbon is marked with a hot lead. I also have a 5v current limited
supply on order. I'm thinking set voltage low and shuffle ground until I
find the 2 pins that provide an output to my frequency meter , then I will
know which ones are my a and b . Once I get the 7i42 I will then be able to
use Hal to find their count me any words of advice or am I solid on this .
Thanks
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2011-12-14 Thread Tom Easterday


On Dec 13, 2011, at 11:08 PM, Jon Elson wrote:
 Tom Easterday wrote:
 
 These are versions without the velocity command at 250ipm and ~1500ipm
 Oh, at 1500 IPM, maybe you need to turn up the servo thread to faster 
 than 1 ms, or
 have you tried that already?

We did try that.  But, I am only able to turn it to down to about 600,000.  
Below that I get realtime errors on the system for some reason (that I don't 
understand).  At 600,000 it didn't seem to help.
-Tom


--
Cloud Computing - Latest Buzzword or a Glimpse of the Future?
This paper surveys cloud computing today: What are the benefits? 
Why are businesses embracing it? What are its payoffs and pitfalls?
http://www.accelacomm.com/jaw/sdnl/114/51425149/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2011-12-14 Thread Tom Easterday


On Dec 13, 2011, at 11:03 PM, Jon Elson wrote:

 Peter C. Wallace wrote:
 Theres a FAQ fom AMT that mentions a jumper on the card that can be removed
 to approximately 1/2 the filter time constant (at the expense of more noise)
 
 And, that is real hard to do once the hub has been glued!  Oops!

Even with the hub glued to the shaft, the encoder still pops out, so you can 
remove the jumper.  We did that yesterday but if it helped it was not obvious.

-Tom


--
Cloud Computing - Latest Buzzword or a Glimpse of the Future?
This paper surveys cloud computing today: What are the benefits? 
Why are businesses embracing it? What are its payoffs and pitfalls?
http://www.accelacomm.com/jaw/sdnl/114/51425149/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

Thanks for the info Jon.  We are seeing a small (about 0.001) position error 
just on initial acceleration and deceleration that we cannot account for.  It 
may be due to the encoder.  Since this is mainly a plasma machine we will 
probably live with it.  If we need to do better we'll look at replacing the 
encoders.  We now know the string attached to our cheap encoder :-)
-Tom

On Dec 13, 2011, at 12:21 AM, Jon Elson wrote:
 Yes, that is EXACTLY the kind of problem I saw.  This encoder is highly 
 interpolated, so
 it has a tracking counter that is incremented or decremented by an 
 estimate of the current
 velocity.  If you don't do these computations correctly, there is a lag 
 in responding to
 changes in velocity.  As far as I can tell, the interpolator in such 
 devices as the Analog
 Devices AD2S1200 has a really fine 2nd or 3rd order filter to make this 
 work well.
 Obviously, CUI did not go to the trouble of such mathematics.
 
 After never being happy with these encoders and having a bit of customer 
 feedback,
 I decided to compare to a standard HP optical encoder (with no 
 interpolation.)
 So, I put the optical encoder on the other end of the motor, and fed 
 both to encoder
 inputs on my PWM controller board.  Most useful was to plot velocity 
 derived from
 both encoders at the same time.  This comes up often enough, I have the 
 plots
 permanently on my web site.  See
 http://pico-systems.com/images/compare_encoder2.png
 
 The red trace is the CUI encoder, which was controlling the motor 
 (badly).  The white
 trace is the HP encoder.  Both are providing 4000 counts/rev.  You can 
 clearly see
 the velocity peaks of the CUI encoder are higher, and if you look 
 closely at the
 slopes, you can see the CUI is slow to react to velocity changes, and 
 then has to
 overshoot significantly so the position can catch up.  This of course 
 accounts for
 the bad servo behavior.  As the Halscope is set for 20 ms/div, the 
 velocity lag
 is easily 3-5 ms in duration!
 
 If you have a plain optical encoder handy, you could easily set up the same
 arrangement to compare the encoders.
 
 Jon


--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Tue, 13 Dec 2011, Tom Easterday wrote:

 Date: Tue, 13 Dec 2011 11:45:41 -0500
 From: Tom Easterday tom-...@bgp.nu
 Reply-To: Enhanced Machine Controller (EMC)
 emc-users@lists.sourceforge.net
 To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
 Subject: Re: [Emc-users] Encoders

 Thanks for the info Jon.  We are seeing a small (about 0.001) position error 
 just on initial acceleration and deceleration that we cannot account for. 
 It may be due to the encoder.  Since this is mainly a plasma machine we will 
 probably live with it.  If we need to do better we'll look at replacing the 
 encoders.  We now know the string attached to our cheap encoder :-) -Tom

Have you tried using FF2 to tune out the lag/lead during accel/decel?

(a jerk limited profile would also help)

Peter Wallace
Mesa Electronics

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
()_() signature to help him gain world domination.

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

Viesturs Lācis wrote:
 2011/12/13 Jon Elson el...@pico-systems.com:
   
 Watch out for the CUI AMT-10x encoders at Digi-Key, they have a lag
 responding to acceleration, and
 may not be well-suited to CNC systems such as EMC2.
 

 Thanks for the warning, Jon!
  I happen to have bought these encoders for one of the machines...
 Do I understand correctly that they are working fine, but I will need
 to decrease max acceleration to get better performance of the encoder?
   
The problem is there is a lag between acceleration and the encoder 
responding to it.
If your servo loop can be tuned for good performance, you are lucky. The 
more
massive the load, the better, I guess. The worst case is a low-inertia 
motor sitting
on the bench. But, if you cannot get the loop response tuned properly, 
then there
really is nothing you can do to fix that. The problem is that when 
velocity changes,
the encoder does not correctly report position. It reports what the 
position WOULD
have been if there had not been an acceleration.

Decreasing max accel will help prevent exciting any unstable response 
from G-code,
but external forces acting on the system cannot be controlled that way, 
and may
excite instability. In other words, reducing accel masks the problem, 
instead of
solving it. Reducing gain will help, but can make the servo response less
accurate.

Jon

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Dec 13, 2011, at 12:52 PM, Peter C. Wallace wrote:
 On Tue, 13 Dec 2011, Tom Easterday wrote:

 Date: Tue, 13 Dec 2011 11:45:41 -0500
 From: Tom Easterday tom-...@bgp.nu
 Reply-To: Enhanced Machine Controller (EMC)
emc-users@lists.sourceforge.net
 To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
 Subject: Re: [Emc-users] Encoders

 Thanks for the info Jon.  We are seeing a small (about 0.001) position error 
 just on initial acceleration and deceleration that we cannot account for. 
 It may be due to the encoder.  Since this is mainly a plasma machine we will 
 probably live with it.  If we need to do better we'll look at replacing the 
 encoders.  We now know the string attached to our cheap encoder :-) -Tom

 Have you tried using FF2 to tune out the lag/lead during accel/decel?

Yes.  Peter (working with me) spent a long time playing with FF2.  We were 
seeing large spikes at first and had FF2 set to 0.007 which helped to lower it 
to .002-.003.  We then realized we had the Granite Devices input filtering 
(which introduces a delay and is documented as doing so) turned on.  Turning 
that off has allowed us to lower FF2 to 0.000105, not zero but getting there.  
The remainder of the delay is now (possibly) coming from the encoder issue Jon 
has pointed out.

 (a jerk limited profile would also help)

What'd you call me?  :-)

What is a jerk limited profile?

-Tom

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

Tom Easterday wrote:
 Thanks for the info Jon.  We are seeing a small (about 0.001) position error 
 just on initial acceleration and deceleration that we cannot account for.  It 
 may be due to the encoder.  Since this is mainly a plasma machine we will 
 probably live with it.  If we need to do better we'll look at replacing the 
 encoders.  We now know the string attached to our cheap encoder 
If you can send me a picture form Halscope, I can compare it to what I 
get.  Are you using FF2?
This can be quite helpful in fixing errors on acceleration.  You have to 
use it in VERY small
amounts, though, like .005 or even less.  It is easy to add too MUCH FF2 
and cause jerks
in the response.  Also, there is a manufacturing issue in these, where 
the encoder ring may
fit loosely on the splined hub that mounts to the shaft.  On some units 
you need to put a
little dab of RTV, super glue or whatever on the splined hub to lock the 
ring to it.  You
can poke the ring with an X-acto knife to see if there is any play 
between it and the hub
when the whole thing is assembled.

Jon

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders


On Dec 13, 2011, at 1:02 PM, Jon Elson wrote:
 The more massive the load, the better, I guess. The worst case is a 
 low-inertia  motor sitting on the bench.

Yes, this is an important point - that we have learned the hard way.   We were 
about to throw in the towel trying to tune our machine.  We have some fairly 
torquey (I can't believe that is actually a word:-) ) motors given the mass of 
the machine.  We finally got a little education on servos and ended up changing 
our gearing from 2:1 to 5:1 (and using an initial 10:1 gearbox attached to the 
motor).  This made ALL the difference in the world.  The machine runs smooth as 
silk now as there is a constant load on the motor to overcome the 10:1 gearing. 
 

Tom
--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders


On Dec 13, 2011, at 1:09 PM, Jon Elson wrote:
 If you can send me a picture form Halscope, I can compare it to what I 
 get.  Are you using FF2?
 This can be quite helpful in fixing errors on acceleration.  You have to 
 use it in VERY small
 amounts, though, like .005 or even less.  It is easy to add too MUCH FF2 
 and cause jerks
 in the response.  

Yes, see post in response to Peter Wallace.

 Also, there is a manufacturing issue in these, where 
 the encoder ring may
 fit loosely on the splined hub that mounts to the shaft.  On some units 
 you need to put a
 little dab of RTV, super glue or whatever on the splined hub to lock the 
 ring to it.  You
 can poke the ring with an X-acto knife to see if there is any play 
 between it and the hub
 when the whole thing is assembled.

Mariss from Gecko suggested this to me early on, so we super glued the collars 
to the shafts.  This did indeed help a little, one of them was slipping badly, 
the others perhaps a small amount.  He also suggested adding a tiny bit of 
silicone caulk to one of the cogs in the gear to take up any slop in the fit 
(both pieces are plastic after all).  I did that as well, but I don't think 
there was much slop to begin with so that provided no noticeable improvement.

-Tom


--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Tue, 13 Dec 2011, Tom Easterday wrote:

 Date: Tue, 13 Dec 2011 13:06:31 -0500
 From: Tom Easterday tom-...@bgp.nu
 Reply-To: Enhanced Machine Controller (EMC)
 emc-users@lists.sourceforge.net
 To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
 Subject: Re: [Emc-users] Encoders

 On Dec 13, 2011, at 12:52 PM, Peter C. Wallace wrote:
 On Tue, 13 Dec 2011, Tom Easterday wrote:

 Date: Tue, 13 Dec 2011 11:45:41 -0500
 From: Tom Easterday tom-...@bgp.nu
 Reply-To: Enhanced Machine Controller (EMC)
emc-users@lists.sourceforge.net
 To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
 Subject: Re: [Emc-users] Encoders

 Thanks for the info Jon.  We are seeing a small (about 0.001) position error
 just on initial acceleration and deceleration that we cannot account for.
 It may be due to the encoder.  Since this is mainly a plasma machine we will
 probably live with it.  If we need to do better we'll look at replacing the
 encoders.  We now know the string attached to our cheap encoder :-) -Tom

 Have you tried using FF2 to tune out the lag/lead during accel/decel?

 Yes.  Peter (working with me) spent a long time playing with FF2.  We were 
 seeing large spikes at first and had FF2 set to 0.007 which helped to lower 
 it to .002-.003.  We then realized we had the Granite Devices input filtering 
 (which introduces a delay and is documented as doing so) turned on.  Turning 
 that off has allowed us to lower FF2 to 0.000105, not zero but getting there. 
  The remainder of the delay is now (possibly) coming from the encoder issue 
 Jon has pointed out.

 (a jerk limited profile would also help)

 What'd you call me?  :-)

 What is a jerk limited profile?

A cubic profile

Currently EMC uses a trapezoidal (linear) velocity profile (so parabolic 
position profile) This means the acceleration profile is a step function. The 
beginning of this step is whats hard to tune around (as you have found)

Jerk is the derivative of acceleration so is infinite with stepped 
acceleration (the current situation with EMC). By using a cubic profile where 
the acceleration is ramped (like velocity is now) starts and stops are much 
gentler and contain less high frequency components that make it hard to tune

 -Tom

 --
 Systems Optimization Self Assessment
 Improve efficiency and utilization of IT resources. Drive out cost and
 improve service delivery. Take 5 minutes to use this Systems Optimization
 Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
 ___
 Emc-users mailing list
 Emc-users@lists.sourceforge.net
 https://lists.sourceforge.net/lists/listinfo/emc-users

Peter Wallace
Mesa Electronics

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
()_() signature to help him gain world domination.

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Tue, 13 Dec 2011, Tom Easterday wrote:

 Date: Tue, 13 Dec 2011 13:20:28 -0500
 From: Tom Easterday tom-...@bgp.nu
 Reply-To: Enhanced Machine Controller (EMC)
 emc-users@lists.sourceforge.net
 To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
 Subject: Re: [Emc-users] Encoders



Theres a FAQ fom AMT that mentions a jumper on the card that can be removed
to approximately 1/2 the filter time constant (at the expense of more noise)

Might be worth a try

www.amtencoder.com/Resources/Frequently-Asked-Questions

Peter Wallace
Mesa Electronics

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
()_() signature to help him gain world domination.


--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders


On Dec 13, 2011, at 1:17 PM, Peter C. Wallace wrote:
 A cubic profile
 
 Currently EMC uses a trapezoidal (linear) velocity profile (so parabolic 
 position profile) This means the acceleration profile is a step function. The 
 beginning of this step is whats hard to tune around (as you have found)
 
 Jerk is the derivative of acceleration so is infinite with stepped 
 acceleration (the current situation with EMC). By using a cubic profile where 
 the acceleration is ramped (like velocity is now) starts and stops are much 
 gentler and contain less high frequency components that make it hard to tune


Thanks Peter.  And how/where does one set this as the velocity profile?
Tom
--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

On Tue, 13 Dec 2011, Tom Easterday wrote:

 Date: Tue, 13 Dec 2011 13:44:01 -0500
 From: Tom Easterday tom-...@bgp.nu
 Reply-To: Enhanced Machine Controller (EMC)
 emc-users@lists.sourceforge.net
 To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
 Subject: Re: [Emc-users] Encoders

 On Dec 13, 2011, at 1:17 PM, Peter C. Wallace wrote:
 A cubic profile

 Currently EMC uses a trapezoidal (linear) velocity profile (so parabolic
 position profile) This means the acceleration profile is a step function. The
 beginning of this step is whats hard to tune around (as you have found)

 Jerk is the derivative of acceleration so is infinite with stepped
 acceleration (the current situation with EMC). By using a cubic profile where
 the acceleration is ramped (like velocity is now) starts and stops are much
 gentler and contain less high frequency components that make it hard to 
 tune

 Thanks Peter.  And how/where does one set this as the velocity profile?
 Tom

Apply ~0.5 man year to Trajectory Planner

 --
 Systems Optimization Self Assessment
 Improve efficiency and utilization of IT resources. Drive out cost and
 improve service delivery. Take 5 minutes to use this Systems Optimization
 Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
 ___
 Emc-users mailing list
 Emc-users@lists.sourceforge.net
 https://lists.sourceforge.net/lists/listinfo/emc-users

Peter Wallace
Mesa Electronics

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
()_() signature to help him gain world domination.

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

2011-12-13 Thread andy pugh

On 13 December 2011 18:44, Tom Easterday tom-...@bgp.nu wrote:

 Thanks Peter.  And how/where does one set this as the velocity profile?

It isn't currently an option with EMC2. Though I think at least some
work has been done around adding it.

-- 
atp
The idea that there is no such thing as objective truth is, quite simply, wrong.

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders


On Dec 13, 2011, at 1:09 PM, Jon Elson wrote:
 If you can send me a picture form Halscope, I can compare it to what I 
 get. 

See: 
http://bgp.nu/~tom/pub/XPosErr-VelCmd.png

These are versions without the velocity command at 250ipm and ~1500ipm:
http://bgp.nu/~tom/pub/XPosError-250ipm.png
http://bgp.nu/~tom/pub/XPosError-Rpaid.png

-Tom

--
Systems Optimization Self Assessment
Improve efficiency and utilization of IT resources. Drive out cost and 
improve service delivery. Take 5 minutes to use this Systems Optimization 
Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

Peter C. Wallace wrote:
 Theres a FAQ fom AMT that mentions a jumper on the card that can be removed
 to approximately 1/2 the filter time constant (at the expense of more noise)
   
And, that is real hard to do once the hub has been glued!  Oops!

Jon

--
Cloud Computing - Latest Buzzword or a Glimpse of the Future?
This paper surveys cloud computing today: What are the benefits? 
Why are businesses embracing it? What are its payoffs and pitfalls?
http://www.accelacomm.com/jaw/sdnl/114/51425149/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders

Tom Easterday wrote:
 On Dec 13, 2011, at 1:09 PM, Jon Elson wrote:
   
 If you can send me a picture form Halscope, I can compare it to what I 
 get. 
 

 See: 
 http://bgp.nu/~tom/pub/XPosErr-VelCmd.png
   
Doesn't look that bad.  I'm a little surprised the FF2 can't make it 
better.  But, then these
systems with multiple smart controllers can be quite hard to tune.

Jon

--
Cloud Computing - Latest Buzzword or a Glimpse of the Future?
This paper surveys cloud computing today: What are the benefits? 
Why are businesses embracing it? What are its payoffs and pitfalls?
http://www.accelacomm.com/jaw/sdnl/114/51425149/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Encoders