Re: [Emc-users] Gecko G213V failed yet again.

2020-12-17 Thread John Dammeyer 
Haven't actually.  I'll do that.  

However, the Chinese Stepper driver runs it like a charm other than an annoying 
3.6kHz whine when it's stopped.  Even with the dip switch set to reduce current 
to half when idle.  The whine is barely detectable with 2A per phase but then 
it won't run the load.
Also a 600oz-in motor I have here also turns nicely with the Chinese one and 
doesn't whine as loud though still at the same frequency.  And since it's half 
the length, half the whine probably makes sense.

I've just ordered an AC Servo to replace it.  It's the same size but will allow 
me 4x the speed.

John


> -Original Message-
> From: jrmitchellj [mailto:jrmitche...@gmail.com]
> Sent: December-17-20 3:23 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Gecko G213V failed yet again.
> 
> By chance have you checked if there is a continuity/resistance from one of
> the windings to the frame of the stepper?
> 
> --J. Ray Mitchell Jr.
> jrmitche...@gmail.com
> 
> 
> 
> "Good enough is the enemy of excellence"author unknown
> 
> 
> On Tue, Dec 8, 2020 at 3:17 PM John Dammeyer  wrote:
> 
> > Hi Gene,
> >
> > > From: Gene Heskett [mailto:ghesk...@shentel.net]
> > > On Tuesday 08 December 2020 02:04:49 John Dammeyer wrote:
> > >
> > > > > I think I'd be measuring the ohmage and inductance of each winding
> > > > > in that motor. A partially shorted winding would be on my suspects
> > > > > list.
> > > > >
> > > > > They should match within a few %. A 10% diff would condemn it in my
> > > > > CET mind.
> > > > >
> > > > > Cheers, Gene Heskett
> > > > > --
> > > >
> > > > Thanks for the suggestion.
> > > > I'll check that too although I'm leaning to epoxy PC board material
> > > > converted to conductive carbon.
> >
> > Unfortunately I can't see which transistor pins go to which terminal
> > pins.  But it appears there isn't a lot of conduction between the winding
> > pins since without the motor connected nothing gets warm.
> >
> > The winding resistances are the same and actually motion is quite smooth.
> >
> > But with the 58.5VDC toroidal power supply meant originally to run a 4
> > axis stepper conversion there's lots of power there to create the specified
> > current.  Now assume for example it's 7 amps and the motor measures at 1.2
> > ohms on each winding.  That's 8.4V steady state across the winding or 58W
> > in the motor.
> >
> > Now we know of course the chopper design will apply the 58V for as long as
> > needed to maintain say the 7A at the top of the micro-stepping curve.  So
> > assume we have 2 ohms DC resistance in a now burnt traces in between
> > layers.  With 7A through that 2 ohms there's a 14V drop.  Not a big deal
> > with the 58V supply.  But 14V and 7A is 98W.  Easily enough to slowly raise
> > the temperature.  And for all I know the resistance is even higher.
> >
> > I hit ESTOP which removes DC power.  Plugged the motor back in.  ESTOP off
> > and the reflective temperature probe shows the bottom pin of the connector
> > quickly reach 40C from 22C.  During all this time the motor itself is
> > barely warm.
> >
> > A far east stepper driver rated for up to 110VDC and 8A is on the way.  Be
> > here next Wednesday so then I can verify that it's the driver.
> >
> > And no answer back from Gecko.
> > John
> >
> >
> >
> >
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> 
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Re: [Emc-users] Gecko G213V failed yet again.

2020-12-17 Thread jrmitchellj 
By chance have you checked if there is a continuity/resistance from one of
the windings to the frame of the stepper?

--J. Ray Mitchell Jr.
jrmitche...@gmail.com



"Good enough is the enemy of excellence"author unknown


On Tue, Dec 8, 2020 at 3:17 PM John Dammeyer  wrote:

> Hi Gene,
>
> > From: Gene Heskett [mailto:ghesk...@shentel.net]
> > On Tuesday 08 December 2020 02:04:49 John Dammeyer wrote:
> >
> > > > I think I'd be measuring the ohmage and inductance of each winding
> > > > in that motor. A partially shorted winding would be on my suspects
> > > > list.
> > > >
> > > > They should match within a few %. A 10% diff would condemn it in my
> > > > CET mind.
> > > >
> > > > Cheers, Gene Heskett
> > > > --
> > >
> > > Thanks for the suggestion.
> > > I'll check that too although I'm leaning to epoxy PC board material
> > > converted to conductive carbon.
>
> Unfortunately I can't see which transistor pins go to which terminal
> pins.  But it appears there isn't a lot of conduction between the winding
> pins since without the motor connected nothing gets warm.
>
> The winding resistances are the same and actually motion is quite smooth.
>
> But with the 58.5VDC toroidal power supply meant originally to run a 4
> axis stepper conversion there's lots of power there to create the specified
> current.  Now assume for example it's 7 amps and the motor measures at 1.2
> ohms on each winding.  That's 8.4V steady state across the winding or 58W
> in the motor.
>
> Now we know of course the chopper design will apply the 58V for as long as
> needed to maintain say the 7A at the top of the micro-stepping curve.  So
> assume we have 2 ohms DC resistance in a now burnt traces in between
> layers.  With 7A through that 2 ohms there's a 14V drop.  Not a big deal
> with the 58V supply.  But 14V and 7A is 98W.  Easily enough to slowly raise
> the temperature.  And for all I know the resistance is even higher.
>
> I hit ESTOP which removes DC power.  Plugged the motor back in.  ESTOP off
> and the reflective temperature probe shows the bottom pin of the connector
> quickly reach 40C from 22C.  During all this time the motor itself is
> barely warm.
>
> A far east stepper driver rated for up to 110VDC and 8A is on the way.  Be
> here next Wednesday so then I can verify that it's the driver.
>
> And no answer back from Gecko.
> John
>
>
>
>
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Re: [Emc-users] Gecko G213V failed yet again.

2020-12-08 Thread John Dammeyer 
Hi Gene,

> From: Gene Heskett [mailto:ghesk...@shentel.net]
> On Tuesday 08 December 2020 02:04:49 John Dammeyer wrote:
> 
> > > I think I'd be measuring the ohmage and inductance of each winding
> > > in that motor. A partially shorted winding would be on my suspects
> > > list.
> > >
> > > They should match within a few %. A 10% diff would condemn it in my
> > > CET mind.
> > >
> > > Cheers, Gene Heskett
> > > --
> >
> > Thanks for the suggestion.
> > I'll check that too although I'm leaning to epoxy PC board material
> > converted to conductive carbon.

Unfortunately I can't see which transistor pins go to which terminal pins.  But 
it appears there isn't a lot of conduction between the winding pins since 
without the motor connected nothing gets warm.

The winding resistances are the same and actually motion is quite smooth. 

But with the 58.5VDC toroidal power supply meant originally to run a 4 axis 
stepper conversion there's lots of power there to create the specified current. 
 Now assume for example it's 7 amps and the motor measures at 1.2 ohms on each 
winding.  That's 8.4V steady state across the winding or 58W in the motor.

Now we know of course the chopper design will apply the 58V for as long as 
needed to maintain say the 7A at the top of the micro-stepping curve.  So 
assume we have 2 ohms DC resistance in a now burnt traces in between layers.  
With 7A through that 2 ohms there's a 14V drop.  Not a big deal with the 58V 
supply.  But 14V and 7A is 98W.  Easily enough to slowly raise the temperature. 
 And for all I know the resistance is even higher.

I hit ESTOP which removes DC power.  Plugged the motor back in.  ESTOP off and 
the reflective temperature probe shows the bottom pin of the connector quickly 
reach 40C from 22C.  During all this time the motor itself is barely warm.

A far east stepper driver rated for up to 110VDC and 8A is on the way.  Be here 
next Wednesday so then I can verify that it's the driver.

And no answer back from Gecko.
John




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Re: [Emc-users] Gecko G213V failed yet again.

2020-12-08 Thread John Dammeyer 
> From: Roland Jollivet [mailto:roland.jolli...@gmail.com]


> Solder a bridging wire under the pcb directly to the output Fet or whatever.
> And/or maybe solder wires from the posts to an off-board connector so there
> are no connectors on the board itself.
> 
I'm not sure which FET to solder to unfortunately.  It's a 4 layer board (maybe 
even 6) and the problem is likely the converted epoxy to carbon between the two 
pins going to one terminal.  So there's current flow through the PC board 
itself.  
Now if GECKO's provided schematics then perhaps...

I could spend hours trying to fix it or instead replace it with one that costs 
$79 Cdn and PRIME shipping. 

So by the 16th I'll have a new driver.  Meanwhile I'm working on an AC Servo 
solution just because...

John
 



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[Emc-users] Gecko G213V failed yet again.

2020-12-08 Thread Roland Jollivet 
Solder a bridging wire under the pcb directly to the output Fet or whatever.
And/or maybe solder wires from the posts to an off-board connector so there
are no connectors on the board itself.



On Tue, 8 Dec 2020 at 06:39, John Dammeyer  wrote:

> The attached photo is of the last time but this time it's not much
> different.  I've resoldered the posts, cleaned everything up including
> polishing the posts and installed a new connector.  With only a few minutes
> running the connector is already quite hot.
>
> So I'm guessing the problem is in one of the middle layers of the PC board
> and either the fibreglass is already so carboned up that it's conducting or
> the trace for the one winding is pretty well toast and has a high
> resistance therefore acting like a toaster.  8-(
>
> So it's a 1200 oz-in stepper motor with a 60V power supply moving the knee
> up and down using a 3:1 reduction to the 0.25" pitch screw.
>
> Any suggestions for an alternative drive?  Really don't want to get
> another Gecko at $201.65 Cdn.
>
> Since I still have two extra HP_UHU drives and 2 STMBLs going to a DC
> Servo motor wouldn't be any more expensive other than the work of mounting
> it and maybe increasing the reduction ratio.  So maybe I should just look
> for an AC or DC Servo motor.
>
> John
>
>
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Re: [Emc-users] Gecko G213V failed yet again.

2020-12-07 Thread Gene Heskett 
On Tuesday 08 December 2020 02:04:49 John Dammeyer wrote:

> > I think I'd be measuring the ohmage and inductance of each winding
> > in that motor. A partially shorted winding would be on my suspects
> > list.
> >
> > They should match within a few %. A 10% diff would condemn it in my
> > CET mind.
> >
> > Cheers, Gene Heskett
> > --
>
> Thanks for the suggestion.
> I'll check that too although I'm leaning to epoxy PC board material
> converted to conductive carbon.
>
> And doing the math if I change to an AC Servo rated at 3.5 NM at 2000
> RPM and update my pulleys to 4:1 from 3:1 I can go from 25 IPM to 125
> IPM compared to the stepper motor.
>
> A change to 4:1 is pretty easy.  Just costs money for pulleys.
> John
>
125 IPM on a mills knee? That's earthquake territory when the knee 
weights 200+ lbs.

Take a look at maybe a 5/1 pulley set, and one of the new 3NM 3 phase 
nema 23 stepper servo's for a few bucks over $100. But you'll need to 
turn that 60 volt supply down as the driver is only rated to 50 volts. 
I've turned a pair of 48 volters down to 42.5, and am plumb amazed at 
what they are doing on my Sheldon lathe. Super quiet like casper the 
ghost. z is moving at over 120 ipm, compared to just barely 60 on a 
motor like the one on your mills knee. Had to use a shorter 2NM version 
for X as the 3NM was too long to put of the back side of the apron. 
Speed went up from 29 to the 60's, hard to measure as the cruising run 
is so short on X. They Just Work.

And both have an error output that I've rigged to do an e-stop and unhome 
the machine if it trips but so far the only trips have been test trips 
from purposely running a tool into a stationary chuck jaw to test. At 
low speeds, spindle off, it isn't pushing hard enough to shatter or 
otherwise damage the chuck jaw or the chip in the tool, it just trips 
the machine off. On my lathe that trips off the motor power supplies, 
which resets the error, hit f2 to re-enable motion, pull the tool, 
rehome the machine, replace the tool, and restart the job. Whats not to 
like?

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] Gecko G213V failed yet again.

2020-12-07 Thread John Dammeyer 
> I think I'd be measuring the ohmage and inductance of each winding in
> that motor. A partially shorted winding would be on my suspects list.
> 
> They should match within a few %. A 10% diff would condemn it in my CET
> mind.
> 
> Cheers, Gene Heskett
> --
Thanks for the suggestion.
I'll check that too although I'm leaning to epoxy PC board material converted 
to conductive carbon.

And doing the math if I change to an AC Servo rated at 3.5 NM at 2000 RPM and 
update my pulleys to 4:1 from 3:1 I can go from 25 IPM to 125 IPM compared to 
the stepper motor.

A change to 4:1 is pretty easy.  Just costs money for pulleys.
John

 



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Re: [Emc-users] Gecko G213V failed yet again.

2020-12-07 Thread Gene Heskett 
On Monday 07 December 2020 23:37:08 John Dammeyer wrote:

> The attached photo is of the last time but this time it's not much
> different.  I've resoldered the posts, cleaned everything up including
> polishing the posts and installed a new connector.  With only a few
> minutes running the connector is already quite hot.
>
> So I'm guessing the problem is in one of the middle layers of the PC
> board and either the fibreglass is already so carboned up that it's
> conducting or the trace for the one winding is pretty well toast and
> has a high resistance therefore acting like a toaster.  8-(
>
> So it's a 1200 oz-in stepper motor with a 60V power supply moving the
> knee up and down using a 3:1 reduction to the 0.25" pitch screw.
>
> Any suggestions for an alternative drive?  Really don't want to get
> another Gecko at $201.65 Cdn.
>
> Since I still have two extra HP_UHU drives and 2 STMBLs going to a DC
> Servo motor wouldn't be any more expensive other than the work of
> mounting it and maybe increasing the reduction ratio.  So maybe I
> should just look for an AC or DC Servo motor.
>
> John

I think I'd be measuring the ohmage and inductance of each winding in 
that motor. A partially shorted winding would be on my suspects list.

They should match within a few %. A 10% diff would condemn it in my CET 
mind. 

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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[Emc-users] Gecko G213V failed yet again.

2020-12-07 Thread John Dammeyer 
The attached photo is of the last time but this time it's not much different.  
I've resoldered the posts, cleaned everything up including polishing the posts 
and installed a new connector.  With only a few minutes running the connector 
is already quite hot. 

So I'm guessing the problem is in one of the middle layers of the PC board and 
either the fibreglass is already so carboned up that it's conducting or the 
trace for the one winding is pretty well toast and has a high resistance 
therefore acting like a toaster.  8-(

So it's a 1200 oz-in stepper motor with a 60V power supply moving the knee up 
and down using a 3:1 reduction to the 0.25" pitch screw.

Any suggestions for an alternative drive?  Really don't want to get another 
Gecko at $201.65 Cdn.  

Since I still have two extra HP_UHU drives and 2 STMBLs going to a DC Servo 
motor wouldn't be any more expensive other than the work of mounting it and 
maybe increasing the reduction ratio.  So maybe I should just look for an AC or 
DC Servo motor.

John


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