Steppers hang when a program finishes! Any ideas?

[ken226]

I just replaced my c10 breakout board with a c11g after a power surge blew my c10.

Everything is running good, excep at the end of a program. Every time it finishes running a program, as the z axis starts moving up, the steppers all stall and miss a bunch of steps.

All other times it runs fine. It jogs fine, all axis run good, programs run fine, its just squeels and misses steps on all 3 axis when it ends a program.

I ran 8 programs today, 30 min to an hour each, and finished my parts but kept having to rezero with edge finders every time a program ended.

Anyone seen this before? Any ideas?

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[CitizenOfDreams]

I presume your programs end with something like G28? Do they have any other moves where all 3 motors turn simultaneously?

[ken226]

I presume your programs end with something like G28? Do they have any other moves where all 3 motors turn simultaneously?

It has a m9, then

g28 g91 z0

Followed by a g28 x0 y0

Then a m30

So, it ends with z going home, then x and y going home. In hindsight, i think its just the z hanging during that move. Not the x and y.

I played around with the motor outputs,active lows in various combinations. Since switching the dir signals on the outputs to active low ive run 3 test programs without a stall.

[ger21]

Since switching the dir signals on the outputs to active

Changing the dir pins will reverse the direction the axis travels, and should have no other effect.

[CitizenOfDreams]

Changing the dir pins will reverse the direction the axis travels, and should have no other effect.

He probably meant STEP pins. Wrong pulse polarity on those would do some funny things, although I am surprised that the rest of his programs worked OK.

[ken226]

He probably meant STEP pins. Wrong pulse polarity on those would do some funny things, although I am surprised that the rest of his programs worked OK.

Yes, i meant the step pins

Good call.

Yea, i found it really weird that it only stalled on the program end. Otherwise, it would run an hours long program stall-free.

[ken226]

Yes, i meant the step pins

Good call.

Yea, i found it really weird that it only stalled on the program end. Otherwise, it would run an hours long program stall-free.

The same problem has returned. I played around with various settings, and enabling Sherline 1/2 pulse mode seems to have fixed it.

So, if shorter step/dir pulses help, should i change the step/pulse settings under "motor tuning?

Currently they are at 3 and 5.

Edited to add:

It started doing it again with Sherline half pulse mode enabled. And also using various other values in the motor tuning pulse duration settings, other than 3 and 5.

I also just noticed that at the moment the little stall/bump occurs, mach 3 gives a little audible chime. Is it possible that the charge pump is switching off a little too early? Perhaps before the steppers have had a chance to return home.

Im running the steppers at 50 ipm maximum during rapids. Should i bump up the motor speed limits?

What are others running for the X Y and Z maximum rapid speeds?

[ger21]

Try setting the step pulse widths to 15.

Then run Task Manager and monitor CPU usage when it stalls.

[ken226]

Try setting the step pulse widths to 15.

Then run Task Manager and monitor CPU usage when it stalls.

Ok, ill try that when i get home from work this evening.


Another annoyance with this C11g board is that my spindle turns on and runs full speed when i boot the computer.it turns back off once mach 3 is started. I've been solving this issue by running the charge pump.

That never happenned either with my old c10 breakout board.

This evening ill also try disabling the charge pump, to see if that cures the stalling issue.

I'm about to the point of scrapping the c11g and buying another c10.

Maybe a smoothstepper board would eliminate the spindle starting during bootup issue?

Edited to add:
The stepper stalls are happening intermittently, occasionally on z during the return to home after program end, but mor often on the x and z, after the z is home and while the x and y are returning home. Never, not once has it occurred during a program or using MDI.

And ive identified the chime sound that i originally thought was coming from mach 3. Its actually coming from windows. It sounds similar to the chime that occurs when a thumb drive is plugged in. That chime always occurs at the exact moment the steppers stall.

I get the same chime from windows if i pull the charge pump jumper while windows is running. Even if mach 3 isnt running. Thats why im leaning toward a charge pump issue.

[ger21]

Sonething in Windows is likely the cause, if it's a Windows sound. Not sure what it could be, though.

[ken226]

Sonething in Windows is likely the cause, if it's a Windows sound. Not sure what it could be, though.

Yea, its weird that it'll run an hour long program, and run it like a champ. Then stall and miss steps while homing at the very end.

Same computer, same software and same setup with a C10 board and C6 spindle card ran since 2014 with no problems.

Ive got a spare C11 board, (non-G model, the big one with every output and input opto-isolated). I think if my charge pump test and pulsewidth tests this evening dint go well, ill swap it in and see what happens.

I've defenitely had as much of the stalling as i can take. I was machining a motor mount for a new BLDC spindle motor, which needed 5 different programs and i felt like i was going to wear out my edge finder having to rezero after every operation.

[ken226]

I swapped out with a couple other boards to test it. With a C11, no stalling. With a C10, no stalling.

Its too bad, i really liked the features of the c11g!