Messages

21

General Mach Discussion / Re: Buzzing steppers

« on: January 04, 2009, 07:26:43 PM »

Hood,
By the way, please don't stay up on my account. This will get solved in time, and you have been very generous with your time. And I am grateful. Go to bed.
Bob

22

General Mach Discussion / Re: Buzzing steppers

« on: January 04, 2009, 07:24:27 PM »

 With electronics, I sometimes feel like a "pig staring at a wristwatch", as my grandpa used to say. But my thinking is this: if I switch a path that I know is working to a motor that has a problem, and that motor runs fine, then I figure that the problem can't be the motor. It doesn't tell me too much about what part of the bad paths are bad, but I think it tells me that the motors are good. Does that make sense? (By "path", I mean the electronic signal coming from the pc, through the controller, and arriving at a motor.)

23

General Mach Discussion / Re: Buzzing steppers

« on: January 04, 2009, 06:49:51 PM »

Brett -- the controller, which I have been calling a drive box, is hooked up to the pc with a printer cable through the printer port. It was going from the pc to an opto BOB, then to the controller, but I bypassed the BOB.
Rich -- If I can get someone over here I will show them your instructions.
Hood -- Yes, when I switched the pins from the x to the y, the problem switched from the x to the y, and visa versa. I concluded therefore that I could eliminate the motors and the PC as the problems, and was left with the BOB and controller. When I bypassed the BOB that left the controller as the major suspect, although I guess the pc or software could somehow be corrupted. Is there a way to check that?
Bob

24

General Mach Discussion / Re: Buzzing steppers

« on: January 04, 2009, 03:36:36 PM »

OK, if I can get someone over here with a scope to look at the signal, where would I look and what would I expect to see?
The steppers didn't get too hot, and I also tried them after sitting for a few hours -- no difference.
Bob

25

General Mach Discussion / Re: Buzzing steppers

« on: January 04, 2009, 03:00:24 PM »

I changed the ports/pins and that changed which motors were acting up. Wouldn't that tell me the same thing?
Bob

26

General Mach Discussion / Re: Buzzing steppers

« on: January 04, 2009, 02:24:34 PM »

I bypassed the BOB and it made no difference. My conclusion, therefore, is that it has to be the drive box, which is what I call the thing that Xylotex sent along with the stepper motors. It, I think, generates the pulses. I sent them an email yesterday and they haven't responded, but it's the weekend, so that may be the reason. Do yu think I'm right in thinking that it's the drive box?
Thanks, Bob

27

General Mach Discussion / Re: Buzzing steppers

« on: January 04, 2009, 01:43:58 PM »

Hi Hood,
I will try to bypass the BOB and see what happens. Part of the problem is that the guy who sold me the BOB won't respond to my questions so I don't know if there is a simple way to check that out. (Arturo Duncan @ cnc4pc.com, by the way).
Rich, I never really cared how fast the table ran, I just set things up so that the motors sounded good -- in the middle of their range. Since the problem I have tried speeding them up and slowing them down, but the sound (imagine a blender filled with gravel) gets worse in both directions. I have also tried adjusting the pulse debounce in both directions with no luck. The fact that it is happening with 2 of the 3 motors ought to be a clue, but I don't know how to read it. And it was working perfectly during its first real project, which it finished with no problem. Then when I tried to jog the Z higher to remove a clamp, it started. Weird.
Thanks again, Bob

28

General Mach Discussion / Re: Buzzing steppers

« on: January 03, 2009, 10:38:31 PM »

Hi Brett,
Thanks for your assistance. I changed the x and y pot/dir pins and as a result the keyboard up/down & left/right arrows changed their control to the other axis, but the original axes that are having the problems still have them. In other words, it looks like the inputs to the motors are OK, and the problem(s) are somewhere else. Any ideas?
Thanks again, Bob

29

General Mach Discussion / Re: Buzzing steppers

« on: January 03, 2009, 07:36:52 PM »

Thanks, Hood, I will try to figure it out.
All the best, Bob

30

General Mach Discussion / Re: Buzzing steppers

« on: January 03, 2009, 07:27:11 PM »

Can I do that by changing the ports and pins settings? It seems strange that 2 of the 3 drives would partially fail at the same moment.