Re: [Emc-users] Encoders

[Gene Heskett]

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 

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Re: [Emc-users] Encoders

[jeremy youngs]

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.
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Re: [Emc-users] Encoders

[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
> > ___
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
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-- 

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Re: [Emc-users] Encoders

[Gene Heskett]

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. 
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-- 
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 

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Re: [Emc-users] Encoders

[jeremy youngs]

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

>
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Re: [Emc-users] Encoders

[Gene Heskett]

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
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-- 
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--
"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 

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Re: [Emc-users] Encoders

[Gene Heskett]

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 

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Re: [Emc-users] Encoders

[jeremy youngs]

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
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Re: [Emc-users] Encoders

[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 
>
> 
> --
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Re: [Emc-users] Encoders

[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.
-- 

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Redondo Beach, California
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Re: [Emc-users] Encoders

[Gene Heskett]

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.

> --
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> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
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-- 
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 

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Re: [Emc-users] Encoders

[jeremy youngs]

A quick Google, digikey and eBay search turned up nothing for an if357 , or
an irf 357 . Any other suggestions?
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Re: [Emc-users] Encoders

[jeremy youngs]

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.
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Re: [Emc-users] Encoders

[Gene Heskett]

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 

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