Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: rfultont on October 22, 2007, 10:18:33 AM

Title: need help! new driver wont work with mach 3
Post by: rfultont on October 22, 2007, 10:18:33 AM
Hi all, was hoping someone might have the answer.  I have been running mach 3 with a xylotex driver bd but it has been stalling out after running for several minutes.  So I am replacing it with a Mechtronics driver board.  I set it up according to it's instruction manual and works great with the kcam that runs the test on it.  But when I hook it to Mach 3, I don't get anything.  I have been over all the settings and nothing looks out of place.  do I need a different post processor,  what setting should I look at??  Please help.  thanks.  Rob   ???
Title: Re: need help! new driver wont work with mach 3
Post by: Chaoticone on October 22, 2007, 11:34:50 AM
You got a link to what you had and what you replaced it with?

Brett
Title: Re: need help! new driver wont work with mach 3
Post by: rfultont on October 22, 2007, 12:18:26 PM
Thanks for the reply, I don't know how to post the links but for the xylotex you go to xylotex.com and the board # is xs-3525/8s-3 and has the data sheet there and the mechtronics is on ebay, item # 230183693887 and the seller is autohec. and he has info on the board there.  Hope this help.  Rob
Title: Re: need help! new driver wont work with mach 3
Post by: Chaoticone on October 22, 2007, 12:47:13 PM
I have sent you a personal message.

Brett
Title: Re: need help! new driver wont work with mach 3
Post by: rfultont on October 22, 2007, 06:47:07 PM
This is my xml file. 
Title: Re: need help! new driver wont work with mach 3
Post by: rfultont on October 23, 2007, 05:26:35 AM
The problem was in the settings-- my drive board was set to slow.

Thanks Brett,  You are a life saver.  I tuned the motors to where they are smooth and singing.  I can't thank you enough! Will be switching it over to the other computer tonight.  Will let you know how it goes.

Rob
Title: Re: need help! new driver wont work with mach 3
Post by: Chaoticone on October 23, 2007, 06:07:08 AM
Your welcome Rob.  :)

Brett
Title: Re: need help! new driver wont work with mach 3
Post by: marko on November 03, 2007, 01:21:12 PM
hi brett
i have also bought the same board from ebay and also have same problem...
could you please help as it really p***ing me off lol

cheers again
Title: Re: need help! new driver wont work with mach 3
Post by: rfultont on November 06, 2007, 05:44:12 AM
Marko, I had to check the "shirline 1/2 step" box on the right side of the config page. It is on the first page I beleive.  hope this helps

Rob
Title: Re: need help! new driver wont work with mach 3
Post by: Dan13 on November 23, 2007, 04:34:25 AM
Hi Rob,
I have the same driver and experiencing some problems with it too.
When I use it with KCam the motors make a lot of noise and rotate only at very low speeds - trying to increase speed results in stalling the motors.
With Mach2 the motors rotate at very high speeds with no problem and surprisingly quite. However, there is a certain mid-range were the motors stall and hum. There is no such setting in Mach2 that I've not tried to adjust, but nothing seems to cure the issue.
This range is approximately between 1500 and 3000 ppm (using full step resolution), i.e. when set to 200 steps per mm the speeds range is 450-900mm/rev. Using micro-step offsets this range to other values. Besides, I do not like using micro-step, as it drastically reduces the motor torque.

Have you encountered something like this, or do you have any guess how can it be fixed?

Thanks,
Daniel
Title: Re: need help! new driver wont work with mach 3
Post by: Chaoticone on November 23, 2007, 06:48:52 AM
Are you using Mach2 or Mach3? Microstepping shouldn't reduce torque at all. It should only increase your resoloution. This may make your steps per second go into a higher KHz range to still get the rapids you want. This may cause problems.

Brett
Title: Re: need help! new driver wont work with mach 3
Post by: Dan13 on November 23, 2007, 09:02:19 AM
Brett,
I use Mach2, though I tried Mach3 and had the same problem.

Miscrostepping does reduce torque, because when you switch to microstepping, then in order to maintain the same speed the driver has to send more frequent pulse rate to the motor. And if you look at a torque diagram of a step motor you can see that the torque decreases with the increase in ppm value. Anyway, that's what I know.

I've just hooked up it all to my PC (the first trials were made with a laptop) and there was the same problem. It's almost two weeks now that I'm  trying to solve this issue, before mounting the motors on the mill, and there is no progress.

Any suggestions?


Daniel
Title: Re: need help! new driver wont work with mach 3
Post by: Chaoticone on November 23, 2007, 09:45:20 AM
Quote
And if you look at a torque diagram of a step motor you can see that the torque decreases with the increase in ppm value. Anyway, that's what I know

This is because the decrease in torque is from the higher RPM the motor is running at. This is different from micro stepping. Steppers usualy fall off pretty quick at a certain RPM, each motor is different. Microstepping does not increase the desired RPM, it simply takes a step and divides it by the given value resulting in higher resoloution. Say you have a motor, 2.8 degrees per step x 200 = 360 degrees. Now, micro stepping x 8 it would be 1600 steps per 360 degrees. Either way, with the motor running at the same RPM, it should have the same torque. I think you are confusing RPM with PPM.   

I have sent you a personal message.

Brett
Title: Re: need help! new driver wont work with mach 3
Post by: Dan13 on November 23, 2007, 10:27:22 AM
Yes. but I mean that I want to maintain the same speeds. I do not want to use microstepping and work 8 times slower.

Anyway, the microstepping issue is of no help for me. It just offsets the stalling range.

Thanks,
Daniel
Title: Re: need help! new driver wont work with mach 3
Post by: comet on November 24, 2007, 01:45:19 PM
HI,
  for my twopenceworth micro stepping will reduce torque at all speeds.
 When I was using steppers I did some experiments.
  Basically put a bathroom weighing scale on the bed and drive the z into it at any speed ,it will
stall the motor and note the weight. then start microstepping,and you will find
that there is less power.
     Tony
Title: Re: need help! new driver wont work with mach 3
Post by: Chaoticone on November 24, 2007, 02:35:39 PM
Tony, I can see where it would make a slight decrease in torque. What were the values you saw? how much difference in micro steppng Vs. full step? I had a remote session with Daniel yesterday and we got his motors turning, but he still has some things to get straight. He can stall his motors with his fingers gripping the shaft. He has just sent me a pm about his power supply, it is drastically undersized.

Brett
Title: Re: need help! new driver wont work with mach 3
Post by: comet on November 24, 2007, 02:58:42 PM
Bret,
  It was a while ago,I cant remember the figures,but I do remember that at 1/16 steps it was delivering
50% less torque.I googled it after and found that it was the case. try it yourself. This was one of the reasons I went to servo's.For all the wasted time I had with steppers, hours of tuning and retuning and harmonics,added to that the sloooow
rapids.I would never build another stepper system.
   Tony