On 10/25/23 12:00, Todd Zuercher wrote:
Gene,
The drive is a "closed loop" stepper drive from Steperonline.
Here is a link to the doc.
https://www.omc-stepperonline.com/index.php?route=product/product/get_file&file=388/CL57T_V4.0.pdf
I've yet to actually power one of these up yet. (Still have a lot more
building to do before I'm ready for that.) But I don't think I'm going to be
asking too much of them. At this point I'm only hoping for at least 1000rpm
from these NEMA23 closed loop stepper motors. (If I can get them to spin
faster great, but I won't be upset if they can't do 2000rpm.)
I'd be looking for high friction someplace if they can't beat 3000 given
enough voltage. They've got 72 volt supplies out now, but that, for
under $40 a copy, should be relegated to one motor, not enough amps to
handle 2 if they are working hard. So until psu's catch up, figure on a
psu per motor.
Actually, I am impressed at the number of high vltage psu's the had
crawled out of the woodwor in the last 6 months.
Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone: (330)828-2105ext. 2031
-----Original Message-----
From: gene heskett <ghesk...@shentel.net>
Sent: Wednesday, October 25, 2023 11:17 AM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] Mesa Step Pulses?
[EXTERNAL EMAIL] Be sure links are safe.
On 10/25/23 08:24, Todd Zuercher wrote:
Hello,
It is my understanding that the step pulses generated by Mesa cards are always
the minimum pulse length set by for example hm2_5i25.0.stepgen.00.steplen, only
the space between the pulses is varied by the step rate, is that correct?
I was reading the manual for the new drive I was planning to use in my next
build and see that the drive calls a preference of a 50% duty cycle for step
pulse inputs. I am guessing that it may have something to do with how the
drive's pulse filtering system works, such that for maximum noise filtering and
step reliability having the pulse length be approximately equal to the step
spacing gives the best results.
So my questions are; Would it be possible to make a Mesa card output a 50%
duty cycle step pattern instead of the current default pattern? And would
doing this even be worth the effort?
Do yopu have a link to that doc?
In the drives I've played with using a function generator, a near 50% ratio can
help when pushing the drive limits, but generally the speed of the
opto-isolator is the ultimate limit, blurring the pulse into almost
unrecognizable signals, slowed by the response times of the opto device used.
For real dependability at 200 khz and up to the failure of the opto, usually
around 375khz, trimming a wee bit one side or the other might get a motor with
no load, just laying on the table some good, getting it upto 2000 revs but
unless the motor voltage is also cranked uo, torque to do actual work at that
speed is just a dream at 45 volts.
Some of the nextgen closed loop drivers can use 90-140 volts, overcoming the
windings inductance much faster, That makes it possible to make usable torque
at 3000 revs. Those higher performance transistors do raise the price a bit.
Particularly in the 3 phase versions. But they run like casper the ghost is
turning the cranks, Quiet.
> Todd Zuercher
P. Graham Dunn
Inc.<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2F
http://www.pgrahamdunn.com/%2Findex.php&data=05%7C01%7Ctoddz%40pgrahamdunn.com
%7C0522ff7789484192c1e808dbd56d7fcc%7C5758544c573f47cebee96c3e0806fb43
%7C0%7C0%7C638338438551181150%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAw
MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sda
ta=GD9S6tywNNdc0N2LZQ6I10zMC0BZScL%2FKumvnpWyoz8%3D&reserved=0>
630 Henry Street
Dalton, Ohio 44618
Phone: (330)828-2105ext. 2031
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, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
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_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
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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, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
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