Stepper motors keep starting and stopping

[Davo242]

i was looking threw some set up videos on youtube and it was showing how to test the driver with mach3, my test showed that mine was pulsing to slow. but when i tried to up the kh it never changed. could this be a slow computer problem?

[JAZZCNC]

i was looking threw some set up videos on youtube and it was showing how to test the driver with mach3, my test showed that mine was pulsing to slow. but when i tried to up the kh it never changed. could this be a slow computer problem?

Not so much slow computer but low voltage parallel port. It's common cause of problems on newer PC's and is most likely your problem if none of the other things I suggested have worked.

The easist/cheapist fix is to use PCI PP card but this can have problems because to all cards work with mach3.
Next option and by far the best is to get way from it and use external motion control card. This option is expensive thou.

Then you have the Drives.?? They are TB based drives and very very delicate things when it comes to voltage so don't what ever you do run them more than 36V or you'll fry them. 24V is safer but this does affect performance you'll get from the motors.

In all honesty they are Rubbish and not something I'd recommend building a machine based on but now you have them.!! . . . Well use them until they die.!
Trying to do CNC on the cheap 99.9% of time costs more than buying decent stuff and with a lot more hair pulling so not worth it.

There is another option you could try and is free and that is using Linux CNC. It may well work better with your PP than Mach3's driver does and end up costing you nothing.
I'm not Linux user so I can't help much on where or how but sure there will be others that can point you in wright direction.

[Davo242]

its an old pc could be 7/8 years or older. is the motion control for the under powered parallel port ? im going to see about getting a newer pc made up on monday is there anything i should be getting in it that would be an advantage ie.. ports drives etc!!
im going to try the new pc on mach3 and if it still isnt working prop il try down loading linux cnc.

[JAZZCNC]

its an old pc could be 7/8 years or older. is the motion control for the under powered parallel port ? im going to see about getting a newer pc made up on monday is there anything i should be getting in it that would be an advantage ie.. ports drives etc!!

I wouldn't waste money on buying a newer PC because it could be just the same. If your going to spend money and intend to use mach3 then buy an external motion control card.
External Motion controller will give you reliable system and higher performance. It will also allow you to use your Old PC because it takes much the work load away from PC. The parallel port is dead dieing technology best avoided.

I suggest before you go spending any more money that you do some research and learn more about Drives, controllers etc. It's all here on the Forum if you look. If not your going to waste money buying more rubbish or stuff that's wrong for your needs.

Which Motion controller depends on your pockets but if you can afford it buy one that uses Ethernet rather than USB. Komatis on the Forum sells Ethernet Smooth steppers which I would recommended.

[Davo242]

Thanks for the advice jazz, I'm going to down load the Linux cnc and see if that solves any issues and if not then I think I will order one of the motion controler and see if that solves the problem. Does it connect to any Bob board? Once agin thanks for the advice.

[JAZZCNC]

Thanks for the advice jazz, I'm going to down load the Linux cnc

Your Welcome and think you will have more success with linux cnc.

[komatias]

Davo,

I too faced motor stalling like you show in the video on my first build. Looked through the cables, voltages step durations etc. I considered that it could have been my Gecko G540 driver so changed that to individual drivers..no improvement.upped the voltage.. Nothing..Never thought that the parallel port would be to blame and definately did not want to spend any more money on the problem.

Every time you lose a step the motors need to reaccelerate. All good and well when they have the voltage to boost them but not so good otherwise. This can leed to stalling as the rotation speed is not ramped but stepped. Hate to burst your bubble but if you are having bench test problems you will have hair pulling moments when you finally build the machine. I know I did even when the bench test was perfect.


Some more reading on the mach forum: http://www.machsupport.com/forum/ind...?topic=9943.30

In todays CNC world it seems that there is just no point in using the lpt unless you have a linux cnc system. Even then a lot of people use a motion control card. For example when i tried Emc with an Asus motherboard it would not pass the test the software performs.
Arguably the first and foremost frustration in any build log seems to be the issue of lost steps for whatever reason,( drivers, noise, lpt port) so eliminating it is money will spent in my opinion. Second will be backlash but that can be managed.

Best regards

George

[Davo242]

Thanks George some good info on the link. The computer I am using is as slow as so I think that is the first port of call, then the smooth stepper which u supply if problems persist.