Stepper problem

[JAZZCNC]

bi polar parallel wants more juice,
you need a 15 amp 36 volt psu
why don't you run them at a higher res?

No he doesn't need that high a supply. He'll never pull any where near that amount of current in normal use. More volts would help increase speed but it wouldn't cause this problem provided they are wired correctly.

Like wise running with a Higher Res or micro stepping being the correct term would only make the matter worse if he's struggling with pulses or the PP has it would require many times more pulses and work for the parallel port.
If he was running at Full step then yes but 1/8 is fine and just about what I'd recommend.

I'll wire only three motors and see what comes out. i'll post pictures/videos if I can.

Just start with one motor then test and see what happens.
Don't bother with wiring in series as you'll need even more volts to get speed. Keep with parallel and set the current setting to match the drive rating.
You do however have a miss match with the motors because those 4 wire motors are most likely series wound motors so will stall a lot sooner up the speed curve than the parallel wired ones with the same voltage.


To test the cable you need a continuity meter or meter set to Ohm's just like for testing phases. Probe pin1 at one end and at the other check it against the others. You should only get a reading between same pins # at each end with no crossover between pins.

[eurikain]

Alright, I'm back after about an hour and a half of testing. Here is what I did:

1. Test the DB25 cable. All pins are through, no cross wires, and they work fine.
2. Wire only one motor, in parallel, with 1/8mcs and 2.7A (as close as I can get to 2.8).
   same problem. Same problem as before. Note that when not moving, the motors make weird sounds..., like a constant little quiet electrical noise, hard to describe.
3. Tried switching DIR and/or STEP active low setting. No change.

Here is what I haven't tried yet and will try tomorrow if you think it's worth it:

1. pins 4 and 8 in all four possible positions (00, 01, 10, 11).
2. switch one motor for the other (if same problem, it's not the motors, it's higher in the chain)
3. switch one driver for the other (if same problem, it's the board that's broken)
4. try another computer, who knows, the only thing I have changed since 2010 is this old computer. But it works fine, so I doubt it comes from there, but with those old guys, you never know.

So, if it's not the cable, not the PSU (already tested), not the motors, and not the drives, it's definitely the board.

What do you guys think ?

[JAZZCNC]

Try setting the step pulse in motor tuning to 5 set Dir to 0 You want the Step in front of the Dir.

[eurikain]

Try setting the step pulse in motor tuning to 5 set Dir to 0 You want the Step in front of the Dir.

Just tried, same problem.

However, when I started Mach3, ran the first test, the motor worked fine for about five seconds before going back to making the same noise as before. Notice that the motor now moves really slowly. When I move it to one direction, it takes several seconds to start, then to slow down. Mach3 indicates correct value as I can see on the screen that the motor takes forever to stop.

EDIT: go to zero function works fine. I'm guessing the bob is fine... may be it's the drivers :/ Oh boy... I think I'm just going to buy a new PSU, new drives, and get a nema23 8 leads to match the others I got...

[JAZZCNC]

EDIT: go to zero function works fine. I'm guessing the bob is fine... may be it's the drivers :/ Oh boy... I think I'm just going to buy a new PSU, new drives, and get a nema23 8 leads to match the others I got...

NO Don't do that.!!!!. . . . . . The Drives, BOB, have NO control over Mach3 what so ever they are effectively UNDER MACH3's control and do exactly has they are told.
So if you are saying the GOTO Zero makes the motors work fine then you have Mach3 setup wrong. How I'm not so sure without seeing the Mach3 XML
So either post pics of your Mach setup screens or Post the XML file your using and I can look at it directly. You'll find it in the Mach3 folder under the same name has the profile your using. ie: MachMill or if Custom profile then name you choose. (You may have to Zip it up to post or Email me directly)

[eurikain]

NO Don't do that.!!!!. . . . . . The Drives, BOB, have NO control over Mach3 what so ever they are effectively UNDER MACH3's control and do exactly has they are told.
So if you are saying the GOTO Zero makes the motors work fine then you have Mach3 setup wrong. How I'm not so sure without seeing the Mach3 XML
So either post pics of your Mach setup screens or Post the XML file your using and I can look at it directly. You'll find it in the Mach3 folder under the same name has the profile your using. ie: MachMill or if Custom profile then name you choose. (You may have to Zip it up to post or Email me directly)

What I meant by "work fine" is that they go back to the correct position, but still having the same problem :( I'll post take pictures of the setup I got and update this post with it, plus I'll join the xml config file in a zip file and attach it here. I'll try to make good pictures so you can see the wiring and see if I've done something wrong. I've checked a couple of times though. No worries I won't buy the electronics until I am sure that those I got are dead ;) Let's figure this thing out. I'll update tomorrow morning :) I'll also make some videos if possible so you can really see what's happening again.

Side note: So nice to see you putting some time in helping me. I will try my best to give back to the community, that lives with people like you !

EDIT: sorry I haven't had the time to post, I'm working this week and will be back home this weekend ;)

[eurikain]

Update on my problems :)

Received my new $10 BOB last week and tried it today. I plugged only one motor. Works like a charm. Plug all motors, boom same problem as before. Unplug all motors and plug just one. Doesn't work with one motor anymore. I turned off the PC, unplugged everything from the BOB. Turn on the PSU and the motors, thought not moving, make a weird high pitch noise, that they make when they don't work correctly. On today's first attempt, the motor plugged was quite when still. So, I am assuming it's either the motors or the drivers.

[eurikain]

Update: my new AM882 drivers arrived a while ago. I wired my new BOB with one AM882, same PSU as before, same motors as before. The AM882 "stall detection" alarm activates when everything is under tension. Therefore, I am assuming that the problem comes from the motors. I will order cnc4you's motors some time later so we will know what was wrong :)

[eurikain]

Update:

I have:
- 4 brand new AM882 drivers
- brand new 5 axis bob
- 4 brand new CNC4YOU Nema23 3.1Nm steppers

AND I AM STILL HAVING THE SAME ISSUE oO !!!!

Would anybody be nice enough to spend a few minutes on Skype with me trying to figure this out before I go buy a new DB25 cable and new computer ? If you are willing to help then send me a PM and i can find any time to talk :)

Thanks a lot !

[uli12us]

Have you connected your wires in exact the same way, like jazz wrote months before.

If yes, have you tested the drivers (and motors) with a small program direct from your printer port of your computer. If you don't have, I must look, if I have one.