On 4 May 2012 05:40, Jon Elson wrote:
> Peter Homann wrote:
> > Jon,
> >
> > IIRC correctly the pre CPLD drives did not have full step morphing. Also
> the
> > new drives have a much improved recirculation sequencing. This means
> that heat
> > sinking requirements for the drives are greatly redu
Peter Homann wrote:
> Jon,
>
> IIRC correctly the pre CPLD drives did not have full step morphing. Also the
> new drives have a much improved recirculation sequencing. This means that
> heat
> sinking requirements for the drives are greatly reduced.
>
Right, I agree about the recirculation ch
On Wed, 2012-05-02 at 20:17 -0500, Jon Elson wrote:
> Kirk Wallace wrote:
> >
> >
> > I suspect the magic is in the Xilinx chip programming, so we'll probably
> > never know what the magic is.
> The G201A and some other drives from years ago used CD4000 CMOS chips and
> had all this. Those drives
Jon,
IIRC correctly the pre CPLD drives did not have full step morphing. Also the
new drives have a much improved recirculation sequencing. This means that heat
sinking requirements for the drives are greatly reduced.
Also the advantage of the CPLD design is that it makes it harder to reverse
Kirk Wallace wrote:
>
>
> I suspect the magic is in the Xilinx chip programming, so we'll probably
> never know what the magic is.
The G201A and some other drives from years ago used CD4000 CMOS chips and
had all this. Those drives could be deciphered fairly easily.
> I'd like to play with a coup
Hi Kirk,
The answer is below. Mariss, puts a lot into the public domain. That way it's
prior art if anyone tries to patent it.
---
The drive generates a reference voltage proportional to speed. This voltage is
sensed by an offset/gain circuit that becomes linear (fro
On 5/2/2012 11:45 AM, Kirk Wallace wrote:
> On Wed, 2012-05-02 at 10:19 -0500, Jon Elson wrote:
> ... snip
>> It just seems to me that when the motor inductance causes the winding
>> current to lag
>> behind the current command from the microstep sine wave, the current control
>> logic will automat
On Wed, 2012-05-02 at 10:19 -0500, Jon Elson wrote:
... snip
> It just seems to me that when the motor inductance causes the winding
> current to lag
> behind the current command from the microstep sine wave, the current control
> logic will automatically become the same as a full-step drive, wi
Peter Homann wrote:
> Better to hear from Mariss himself.
>
>
> Simple drives persist in microstepping anyway above this speed. This means
> they still try to make the motor phase currents sine and cosine past this
> speed. A little problem with that and it's called 'area under the curve'. The
Peter wrote:
>
>
> Jon,
>
> It doesn't "switch" from 1/10 to full-step, it "morphs". It's not done
> with clocks and dividers, its done more in the analog side. That's the
> difference that Mariss adds. Anyone can built a microstepping drive. There
> are scores of application notes and open sour
Better to hear from Mariss himself.
-
It's a give and take kind of situation:
1) For the same peak current, a microstepped motor will have 71% (1/sqrt 2)
the holding torque of a full-step drive. This is because motor
Jon,
It doesn't "switch" from 1/10 to full-step, it "morphs". It's not done
with clocks and dividers, its done more in the analog side. That's the
difference that Mariss adds. Anyone can built a microstepping drive. There
are scores of application notes and open source designs. To do what
Geck
Viesturs Lācis wrote:
> 2012/5/1 John Thornton :
>
>> The G203v's that I use on my plasma cutter are smooth as silk and when
>> you adjust the morphing pot you can really tell the difference when it
>> is adjusted correctly.
>>
>
> Hmm, I put 6 G203v drives in the welding robot, but did not
andy pugh wrote:
> On 1 May 2012 12:26, cogoman wrote:
>
>> I don't see how they could switch from 1/10 to full step without letting
>> LinuxCNC know, and having LinuxCNC reduce the number of steps being
>> sent, unless they used a clock multiplier, which would make it look like
>> full step to
On Tue, 2012-05-01 at 23:48 +1000, Peter Homann wrote:
> You run it at a couple of RPS. Its the speed where you notice that its smooth
> rather than silky smooth. :)
>
> Then adjust the pot to get it as smooth as you can.
>
> Cheers,
>
> Peter.
I suspect, and I may be way off base, the 2 RPS (
I use a chinese model with DSP, and it include 3 notch finder that kill
resonance frequency. (well, this is not exactly a notch finder, but it
kill a mechanical resonance)
even using the microstep mode, if you need a really smooth motion, you
will notice that a standard stepper driver (even wit
You run it at a couple of RPS. Its the speed where you notice that its smooth
rather than silky smooth. :)
Then adjust the pot to get it as smooth as you can.
Cheers,
Peter.
On 1/05/2012 10:29 PM, John Thornton wrote:
> I think it works no matter what but it is smoother if you adjust it. I
> f
I think it works no matter what but it is smoother if you adjust it. I
forget the RPM you run the stepper at then tune for smoothest sound and
done.
John
On 5/1/2012 7:21 AM, Viesturs Lācis wrote:
> 2012/5/1 John Thornton:
>> The G203v's that I use on my plasma cutter are smooth as silk and whe
2012/5/1 John Thornton :
> The G203v's that I use on my plasma cutter are smooth as silk and when
> you adjust the morphing pot you can really tell the difference when it
> is adjusted correctly.
Hmm, I put 6 G203v drives in the welding robot, but did not touch that
small tuning pot and the robot
The G203v's that I use on my plasma cutter are smooth as silk and when
you adjust the morphing pot you can really tell the difference when it
is adjusted correctly.
John
On 4/30/2012 4:46 PM, Kent A. Reed wrote:
> Gene brought up mechanically damping mid-band resonance in a stepper.
> I'm old s
The motor sees the change electrically, the interface to LinuxCNC does
not change.
It is all internal to the Gecko drive.
Dave
On 5/1/2012 7:26 AM, cogoman wrote:
> I don't see how they could switch from 1/10 to full step without letting
> LinuxCNC know, and having LinuxCNC reduce the number of
On 1 May 2012 12:26, cogoman wrote:
> I don't see how they could switch from 1/10 to full step without letting
> LinuxCNC know, and having LinuxCNC reduce the number of steps being
> sent, unless they used a clock multiplier, which would make it look like
> full step to the control,
I imagine it
I don't see how they could switch from 1/10 to full step without letting
LinuxCNC know, and having LinuxCNC reduce the number of steps being
sent, unless they used a clock multiplier, which would make it look like
full step to the control, and just use microstepping to smooth out the
full steps
Hi Jon,
Yes, the Geckos are one of the few drives that have electronic
anti-resonace built it. The other feature that improves the performance is
that they morph from 1/10 to fullstep as the stepper rpm increases. This
overcomes the deficiencies of using microstepping at faster rpms, and
gives
Kent A. Reed wrote:
> Question to y'all. Do these electronic techniques deliver the goods?
I can tell you that the Gecko 201A from way back around 2000 were quite
awesome.
I have fooled around with steppers for some time, and the G201 was the first
drive I would even consider for a CNC application
On Mon, 30 Apr 2012 16:52:21 -0500, you wrote:
>from my experience - full step/ half step/ 1/4 step all seem to have
>problems with resonance (although 1/4 step is much reduced).Once you
>get into microstepping drives - that problems seems to go away. ie - we
>have never had a resonance pr
from my experience - full step/ half step/ 1/4 step all seem to have
problems with resonance (although 1/4 step is much reduced).Once you
get into microstepping drives - that problems seems to go away. ie - we
have never had a resonance problem with drives we have used that are at
least 10
Gene brought up mechanically damping mid-band resonance in a stepper.
I'm old school and mechanical/inertia dampers are all I know. Folks have
posted videos to YouTube that show the efficacy of this approach.
However, I've noticed a number of stepper-drive vendors claim to have
electronic solut
28 matches
Mail list logo
