[Emc-users] Rpi

[jeremy youngs]

I'm about to purchase the rpi 3 b to convert my other mill. I'm going to
use the steppers I took off this matson . Probably 7i90 as well. I have a
couple VGA monitor so I figured I'd get a HDMI to VGA cable . Is there any
reason not to get this?
eBay item number 323251929837
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Re: [Emc-users] Got LCNC into a corner, painted in you might say

[Gene Heskett]

On Sunday 27 May 2018 19:37:04 Gene Heskett wrote:

> On Sunday 27 May 2018 17:16:50 Gene Heskett wrote:
> > Giveing up on the jig brace, I decided to make a wooden one as it
> > doesn't have to last till the rapture. I laid out a circle, then
> > contemplated how to draw this circle such that its position was
> > offset half a mm for each time that it was drawn, until I got the
> > proper depth of cut.
> >
> > Without doing the arcgenm18 routine in 50 pieces of code, I tried to
> > make a sub routine out of it by manipulating the y offset, but
> > whilew it moved, it didn't want to do it in a straight line up the y
> > axis, but wandered off the the right and got smaller. I moved vars
> > around, but that failed similarly. So I got this wild hair to move
> > the co-ordinate, then I could re-use the same subroutine until I'd
> > hit the offset I wanted. But I stopped it as it was starting the 2nd
> > semi-circle, which means the y coordinate had been moved what I
> > thought was half a mm.
> >
> > But on further study of the docs, neither G10 L2 or G10 L20 take
> > anything but absolute values.
> >
> > So this means I have to get the current y coordinate from the memory
> > for P1's map, add my small var, and rewrite y with a G10 L2 y new
> > value.
> >
> > Except I moved it 40mm with the first command, and now it says the
> > first mpve will exceed the y limits. Then I noticed the - sign was
> > missing too for y.
> >
> > Is this a place where I have to g53 g0 x0 y0 z0
> > and then rewrite the p1 map to all balls at that location? A
> > shutdown, restart and rehome has not fixed it. Then reset y for each
> > pass with G10 L2 P1 y[#5222 + 0.5000] mm mode!
> >
> > And end the program with either a saved initial #5222, or another
> > g53 etc etc?
>
> And I just found out why the corrections applied are so gross as to
> disable lcnc. The value stored is in #5222(G54Y) is in inches, despite
> its being in G21 mode. So I need to divide my var for increments by
> 25.4 to make it inches.  Sigh... Sure as hell there ought to be a way
> to walk a D pattern in a while loop without unrolling it to a 50kb
> file.
>
> Funny part is it looks great in the back plot.
>
> Thanks

To those who wondered, its working and the poplar block is carved, and 
while I haven't carved brass in it yet, its quite a bit more rigid. I'm 
out of clamps so the tailstock is on a ladder step nearby, I bent up a 
6" piece of 1/8" alu panel that gently holds the slug into a r8 driven 
by the table, so I think its going to work better than anything else 
I've tried, lots better. I wound up sampling #5222 into a global var and 
referencing that, the didling it to offset the tool a wee bit for each 
pass thru the while loop, gradually digging the U channel deeper. And 
restoring the Y offset by putting the global var back into #5522 as it 
wraps up the job.

To Jon; I had to reset the pwm-servo several times, it was tripping off 
at the m5, which is completely off while the motor was cranking the 
spindle at 1500. So thinking about the motors emf, I put an s100, g4p.5 
in front of the m5.  Hasn't tripped again. Its probably down to 100 revs 
in .1 seconds, maybe less.  As a 4 quadrant controller, when its active, 
the motor responds _now_. I once measured the turnaround time at about 
400 milliseconds from 2800 to -2800, or back, accompanied of course by a 
short chirp of the iron from the 16 amp current limit I set in deference 
to the wire gage in the PSU transformers. And that signal from motion 
has a limit3 in series with it to slow that rail to rail signal down so 
the servo's current limiter doesn't have to do it all.
 
You make good stuff Jon. For anyone else similarly abusing Jon's 
pwm-servo, by running a 1 HP spindle motor with it, from a 127 volt psu, 
if its tripping the reset and turning on the led at a stop, put an s100 
in front of the m5, along with enough time delay for the motor to be 
slowed. Should be the end of the problem.

-- 
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] magnetic field

[Jon Elson]

On 05/27/2018 05:22 PM, andy pugh wrote:

On 27 May 2018 at 20:03, a k  wrote:


possible to notice that hair - start move. like someone
touching it. right?
this is magnetic field touching. right?
Probably not. I think it is more likely to be the electric 
field.
Though i think that blood is ferromagnetic so it is just 
about

possible.

It is not something that I have ever felt, but I can feel 
when

appliances are not properly earthed by stroking them.

I can sense large magnetic fields.  But, it has to be REALLY 
strong, as in an MRI magnet.
I get a slight dizzy feeling when in the presence of this 
class of magnetic field.  I have friends who work on MRIs, 
and they have checked the field with magnetometers, and say 
I am about right where I say I start to feel the field.


I can't imagine any motor producing such a field.  You know 
it is a strong field when keys start moving around in your 
pocket when you are 20 feet away from the magnet, on the 
outside of the shielded wall.


Yes, I can also detect AC leakage in appliances, mostly with 
the back of my hand, but sometimes other parts.


Blood is supposed to be NON-ferromagnetic due to the 
Hemoglobin structure.  Which is good, as I can't imagine 
what a 5 T MRI magnet would do to a person otherwise.


Jon



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Re: [Emc-users] Got LCNC into a corner, painted in you might say

[Gene Heskett]

On Sunday 27 May 2018 17:16:50 Gene Heskett wrote:

> Giveing up on the jig brace, I decided to make a wooden one as it
> doesn't have to last till the rapture. I laid out a circle, then
> contemplated how to draw this circle such that its position was offset
> half a mm for each time that it was drawn, until I got the proper
> depth of cut.
>
> Without doing the arcgenm18 routine in 50 pieces of code, I tried to
> make a sub routine out of it by manipulating the y offset, but whilew
> it moved, it didn't want to do it in a straight line up the y axis,
> but wandered off the the right and got smaller. I moved vars around,
> but that failed similarly. So I got this wild hair to move the
> co-ordinate, then I could re-use the same subroutine until I'd hit the
> offset I wanted. But I stopped it as it was starting the 2nd
> semi-circle, which means the y coordinate had been moved what I
> thought was half a mm.
>
> But on further study of the docs, neither G10 L2 or G10 L20 take
> anything but absolute values.
>
> So this means I have to get the current y coordinate from the memory
> for P1's map, add my small var, and rewrite y with a G10 L2 y new
> value.
>
> Except I moved it 40mm with the first command, and now it says the
> first mpve will exceed the y limits. Then I noticed the - sign was
> missing too for y.
>
> Is this a place where I have to g53 g0 x0 y0 z0
> and then rewrite the p1 map to all balls at that location? A shutdown,
> restart and rehome has not fixed it. Then reset y for each pass with
> G10 L2 P1 y[#5222 + 0.5000] mm mode!
>
> And end the program with either a saved initial #5222, or another g53
> etc etc?

And I just found out why the corrections applied are so gross as to 
disable lcnc. The value stored is in #5222(G54Y) is in inches, despite 
its being in G21 mode. So I need to divide my var for increments by 25.4 
to make it inches.  Sigh... Sure as hell there ought to be a way to walk 
a D pattern in a while loop without unrolling it to a 50kb file.

Funny part is it looks great in the back plot.

Thanks


-- 
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] magnetic field

[Gene Heskett]

On Sunday 27 May 2018 18:22:00 andy pugh wrote:

> On 27 May 2018 at 20:03, a k  wrote:
> > possible to notice that hair - start move. like someone
> > touching it. right?
> > this is magnetic field touching. right?
>
> Probably not. I think it is more likely to be the electric field.
> Though i think that blood is ferromagnetic so it is just about
> possible.
>
> It is not something that I have ever felt, but I can feel when
> appliances are not properly earthed by stroking them.

Use the back of your hand Andy, its much more sensitive.


-- 
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] magnetic field

[andy pugh]

On 27 May 2018 at 20:03, a k  wrote:

> possible to notice that hair - start move. like someone
> touching it. right?
> this is magnetic field touching. right?

Probably not. I think it is more likely to be the electric field.
Though i think that blood is ferromagnetic so it is just about
possible.

It is not something that I have ever felt, but I can feel when
appliances are not properly earthed by stroking them.

-- 
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

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[Emc-users] Got LCNC into a corner, painted in you might say

[Gene Heskett]

Giveing up on the jig brace, I decided to make a wooden one as it doesn't 
have to last till the rapture. I laid out a circle, then contemplated 
how to draw this circle such that its position was offset half a mm for 
each time that it was drawn, until I got the proper depth of cut.

Without doing the arcgenm18 routine in 50 pieces of code, I tried to make 
a sub routine out of it by manipulating the y offset, but whilew it 
moved, it didn't want to do it in a straight line up the y axis, but 
wandered off the the right and got smaller. I moved vars around, but 
that failed similarly. So I got this wild hair to move the co-ordinate, 
then I could re-use the same subroutine until I'd hit the offset I 
wanted. But I stopped it as it was starting the 2nd semi-circle, which 
means the y coordinate had been moved what I thought was half a mm.

But on further study of the docs, neither G10 L2 or G10 L20 take anything  
but absolute values.

So this means I have to get the current y coordinate from the memory for 
P1's map, add my small var, and rewrite y with a G10 L2 y new value.

Except I moved it 40mm with the first command, and now it says the first 
mpve will exceed the y limits. Then I noticed the - sign was missing too 
for y.

Is this a place where I have to g53 g0 x0 y0 z0
and then rewrite the p1 map to all balls at that location? A shutdown, 
restart and rehome has not fixed it. Then reset y for each pass with
G10 L2 P1 y[#5222 + 0.5000] mm mode!

And end the program with either a saved initial #5222, or another g53 etc 
etc?

-- 
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] magnetic field

[Gene Heskett]

On Sunday 27 May 2018 15:03:22 a k wrote:

> hi
> i was thinking about problem that i got and have some ideas.
> when one come close to the large motor - any motor - size of
> motorcycle or small car , possible to notice that hair - start move.
> like someone touching it.
> right?
> this is magnetic field touching. right?
> such large motor always grounded. only super large business use such
> motors.
> i am talking about such large motor because no  need to special
> magnetometor to detect magnetic field- hair is enough .
> what will happen if next to such motor put any coil or any metal body
> -sheet metal etc?
> the electricity will be generated. right?
> if one will grounded this metallic part /coil next to large motor ,
> what will happen?

That is highly dependant on the motor.

> that will effect large motor through magnetic field- without direct
> contact to any large motor wiring etc.
> my point. every motor will generate magnetic field - outside of motor
> body. this magnetic field will have very strong robust effect on metal
> object that close to motor as much as effect motor performance them
> self. if some coil must be placed close to the motor then such motor
> must be tune in same environment-situation.
>
> just a thinking

And not. Whats basic is that any electric motor, is also a generator. But 
the common squirrel cage armature has no external circuits, its all a 
short circuit, so if its spinning, and a DC current is applied to the 
field windings, creating a magnetic field thru which the armature is 
turning, all its generated current goes into the shorting rings on the 
ends of the armature. Since it takes energy to generate that current, 
the motor turns into a braking system. A huge pulse of heat is 
developed, but the heating is over so fast because it has slowed, so its 
not often the heat is noticed. If the current is not turned off, and you 
try to turn the shaft, it will turn, but slowly like its full of 
mollasses.

The external magnetic field is quite weak, again the motor is less 
efficient if it has high magnetic leakage, so its to the makers 
advantage to use a magnetic structure that minimizes this leakage since 
it causes the motor to need more power to develop x horsepower.

Some PMDC motors have horrible leakage, but they just use bigger, 
stronger magnets to make up for that, its a one time cost the customer 
doesn't have to pay for.

I haven't a clue where you were/are going with this line of thought, but 
just consider that there is no such thing as a perpetual motion machine, 
TANSTAAFL wins that argument every time.
 
-- 
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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[Emc-users] magnetic field

[a k]

hi
i was thinking about problem that i got and have some ideas.
when one come close to the large motor - any motor - size of motorcycle or
small car , possible to notice that hair - start move. like someone
touching it.
right?
this is magnetic field touching. right?
such large motor always grounded. only super large business use such
motors.
i am talking about such large motor because no  need to special
magnetometor to detect magnetic field- hair is enough .
what will happen if next to such motor put any coil or any metal body
-sheet metal etc?
the electricity will be generated. right?
if one will grounded this metallic part /coil next to large motor , what
will happen?
that will effect large motor through magnetic field- without direct contact
to any large motor wiring etc.
my point. every motor will generate magnetic field - outside of motor body.
this magnetic field will have very strong robust effect on metal object
that close to motor as much as effect motor performance them self.
if some coil must be placed close to the motor then such motor must be tune
in same environment-situation.

just a thinking
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Re: [Emc-users] rotary tables, was Home switches.

[Gene Heskett]

On Sunday 27 May 2018 10:06:10 Gene Heskett wrote:

> On Sunday 27 May 2018 09:02:21 Ken Strauss wrote:
> > Paypal is an option.
>
> According to their web site last night, paypal is not accepted.
 Using "collet black" as a search term on fleabay did get some hits from 
NA places.  But I've come to the conclusion that a gear drive hose clamp 
on the nose of the R8, and the tables tailstock on the far end of the 
workpiece is still subject to too much slippage opportunities.

So I am going to round up a block big enough to cut a half circle that 
just fits the relaxed size of the r8 collet at the bottom of the skirt, 
and clamp that to the table under the end of the r8. That, combined with 
the tail stock should prevent it canting when the pressure of the drill 
hits it. I was cutting a flat on the side so the drill didn't walk, but 
found a better idea, bring the drill to within a half a mm, then go down 
at 2mm/minute and the drill doesn't walk while making its starter 
dimple, then send it on down to intersect the central tap shank bore at 
about 40mm/min. But that seems to harden the brass at the point of 
contact, and the force of speeding up the drill pushes the workpiece 
canted lengthwise. Back off and then come back down and it seems to cut 
thru the hard layer and keep going. Fix my code to make that move, and 
make a follower to brace the bottom of the r8, which is sticking out of 
the chuck around 4" and has no clamp on the workpiece other than its 
friction fit. Or, better yet, size the follower to fit the bottom of the 
workpiece and put it directly under the drills path.  Yeah, I like that 
even better. I've still got about 40 left to do.

Now if I could get one of the neighbors kids to cut my grass, its a 
jungle, and in the middle 80's here.

-- 
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] rotary tables, was Home switches.

[Gene Heskett]

On Sunday 27 May 2018 09:02:21 Ken Strauss wrote:

> Paypal is an option.
>
According to their web site last night, paypal is not accepted.


-- 
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] rotary tables, was Home switches.

[Ken Strauss]

Paypal is an option.

> -Original Message-
> From: Gene Heskett [mailto:ghesk...@shentel.net]
> Sent: Saturday, May 26, 2018 11:22 PM
> To: emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] rotary tables, was Home switches.
>
> On Saturday 26 May 2018 19:35:20 Ken Strauss wrote:
>
> > I haven't found a North American supplier but shipping by ArcEuro only
> > takes a few days. I recently got an ER40 square/hex pair from them. At
> > current exchange rates 1 UKP is about us$1.14. Note, VAT does not
> > apply to shipments to outside the EU so assume 1 pound = 1 dollar.
> >
> And this is upsetting me, my bank declined the off shore charge.
> They've been known to use more stringent anti-fraud measures outside of
> normal business hours or on a long holiday before. So I sit and simmer
> till Tuesday I guess. They don't get it that I'm retired & have been
> since the middle of 2002. I don't often wear a watch, or pay attention
> to what day of the week it is.
>
> > > -Original Message-
> > > From: Gene Heskett [mailto:ghesk...@shentel.net]
> > > Sent: Saturday, May 26, 2018 7:05 PM
> > > To: emc-users@lists.sourceforge.net
> > > Subject: Re: [Emc-users] rotary tables, was Home switches.
> > >
> > > On Saturday 26 May 2018 18:58:32 Gene Heskett wrote:
> > > > On Saturday 26 May 2018 18:20:14 andy pugh wrote:
> > > > > On 25 May 2018 at 17:47, Gene Heskett 
> wrote:
> > > > > > Its a piece of India made 4" junk.
> > > > > > Handy for facing bolt head flats,
> > > > >
> > > > > I tend to use these for that:
> > > > > http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collet-Fixtur
> > > > >es/E R3 2-Collet-Blocks
> > > >
> > > > I have wished for something like that, but thats the first I've
> > > > actually seen such a critter. Next time it comes up, I'll see if
> > > > they ship to the middle of the US.
> > > >
> > > > > Much quicker to set up. Just hold the bolt in a collet and hold
> > > > > the block in the machine vice.
> > > > > The square one would work well for drilling grub-screw holes in
> > > > > tap hats.
> > > >
> > > > That it would, but I've got a lashup that works most of the time
> > > > now.
> > > >
> > > > I didn't see a price, can you venture a SWAG?
> > >
> > > Its there in pounds or euro's if I scroll down far enough. Looks
> > > like the best deal, one of each and a nut for 33 something. Most
> > > brit stuff is quite reasonable.
> > >
> > > > > I don't know if there is a US supplier.
> > > >
> > > > Thanks Andy.
> > >
> > > --
> > > 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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> > 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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