2 Attachment(s)
Stepper motors not running smooth MACH3 LPT
Hello people.
I have an issue, mine stepper motors not running smooth, its like PC is not sending pulses to motors continously. Its like there are some delays at random times between pulses.
Also sound of motors is not continous, noises every cca half a second, and alot of vibrations cause of it.
I run via MACH3, Windows XP. I ran DriverTest in Mach3 folder and graph looks like this.
I've done some things already: Formatted and Reinstall windows, change PC mode from ACPI to Standard PC change pulse width from 0 to 5us in Motor Tunning in MACH3... and strange motor running is still present. I have DB25 1205 breakout board and its connected via LPT.
Do you have any recommendations what to do?
https://www.cnczone.com/forums/attac...d=482812&stc=1
Thank you, Matic
Attachment 483177
Re: Stepper motors not running smooth MACH3 LPT
You also could do with telling us:
What machine you are using it on.
Which stepper motors.
Which stepper drivers.
What voltage/ampage power supply you're using to run the drivers.
Re: Stepper motors not running smooth MACH3 LPT
My custom made CNC.
Stepper motors: https://www.omc-stepperonline.com/p-...s-24hp39-5004s
Stepper drivers: https://www.longs-motor.com/stepper-...er-dm860a.html
Power supply: DC 60V 5.9A, I have 3 PS's, one for each motor driver.
Re: Stepper motors not running smooth MACH3 LPT
You have to experiment with different amp and step setting till you find the sweet spot.
Re: Stepper motors not running smooth MACH3 LPT
Quote:
Originally Posted by
liefer
You have to experiment with different amp and step setting till you find the sweet spot.
Thank you, I already tried many different settings at stepping and amperage but motors runing strangely no matter I change the settings.
I think the problem is at PC due to unstable output frequency through parallel port LPT.
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Re: Stepper motors not running smooth MACH3 LPT
Quote:
Originally Posted by
dazp1976
Well, that certainly isn't a bad setup. I'd expect them to fly. For the 5A motors I normally set driver peak at 4.9A. Then keep an eye on motor heat. If pretty cool set to 5.7A peak and check again.
I use MM for measurement, and 5mm pitch screws.
For this bob and the above MM/pitch I'd start with:
Mach set at 25khz.
Driver per rev at 1000.
Steps per at 200.
My us were set at 3 & 8
That will give you good max velocity available.
If it works well then try:
25khz.
2000.
400.
If available max velocity is too low then put Mach at 35khz.
Tbf, 35khz/2000/400 settings are about enough for these boards.
Do you have the wiring diagram you used for the bob & drivers?.
Thank you.
Motor heat is ridiculous, they are very hot IDK why btw. I have 4mm and 3mm on Z axis pitch screws.
Good I will try this setup you wrote once I get my motors running smoothly.
Yes I wrote diagram here you are:
https://www.cnczone.com/forums/attac...d=482818&stc=1
2 Attachment(s)
Re: Stepper motors not running smooth MACH3 LPT
Quote:
Originally Posted by
dazp1976
Darn if. Your best option now then is either:
1. Get a cheap new motherboard and replace it. Or a cheap pc. Usually loads on ebay.
2. Get an ETHERNET controller and hook up your existing bob to it via DB25-IDC26 cable.
DO NOT waste your time with usb controllers. Nearly every problem I see is when using a USB.
(well except for whan a pport fails).
Thank you!
1. Good, I will try to replace motherboard with processor on it (i have one old pc laying around at home) and reinstall everything, do you suggest WIN XP, SP2 or SP3?
2. Do you think that I should replace my DB25 1205 BOB with ethernet BOB? I was googling and found this one: Novusun NVEM V2 Ethernet BOB and run it via ethernet connection insead of parallel port?
My DB25 1205 cheap BOB with LPT:
https://www.cnczone.com/forums/attac...d=482822&stc=1
Novusun NVEM V2 Ethernet
https://www.cnczone.com/forums/attac...d=482820&stc=1
Re: Stepper motors not running smooth MACH3 LPT
Hi,
the Novosun you linked to is a genuine motion controller and would be much better than a parallel port, but I would not choose that one. Novosun peddle pirate copies of Mach3
and get NO support on the Mach forum.
If you want to buy a motion controller buy a US or European made one, don't buy Chinese rubbish.
UC300
57CNC
Ethernet SmoothStepper
Hicon
are all good.
The second board you linked to is just a parallel port breakout board, it won't help your PC which is suffering from excess jitter.
Craig
Re: Stepper motors not running smooth MACH3 LPT
Hi,
eight-nine years ago I bought an Ethernet SmoothStepper to replace my existing parallel port. I'd had a good run with the parallel port and would have sworn that is
was operating well. When I got an ESS I was able to get my steppers to go 33% faster without losing steps. I would not have thought the the jitter of the parallel port
was too bad....but it must have been.
Craig
Re: Stepper motors not running smooth MACH3 LPT
Hi,
it very tempting to believe that increasing the number of microsteps also increases the resolution, but the practical reality is that it does not. The effective best
resolution for a two phase stepper occurs at half-stepping, ie 400 pulses per revolution.
The real reason we use microstepping is smoothness of motion. The idea was first invented by astronomers who wanted much smoother motion from the steppers they use on their
telescopes. The higher the microstepping the smoother the motion, however the higher the microstepping requires ever faster signalling to the driver to cause the stepper to spin at
maximum speed, and you may find the parallel port is just too slow.
For instance lets assume you want the stepper to spin at 600rpm (10 revs/sec) to make the machine go as fast as you want:
4 microsteps per fullstep =800 pulses /rev and at 10 revs/sec requires a pulse rate of 8000 pulses/sec.
32 microsteps per fullstep=6400 pulse/rev and at 10 revs/sec requires a pulse rate of 64000 pulse/sec
So you can see that a parallel port would have almost no chance of driving the stepper to full speed at 32 micro step per full step but have no trouble
driving it to full speed at 4 microsteps per full step.
For this reason most people use 4, 5, 8 or 10 microsteps pert full step, corresponding to 800, 1000, 1600, 2000 pulses per rev. It s good balance to get smooth motion
without requiring blindly fast pulses from your controller.
craig