random stalling g540

[ihavenofish]

ive been finally making use of my g540 enabled kx1 machine, and ive run into an odd issue.

my x and z axis seem to randomly stall for a few moments during a program run. doesnt happen every time, but maybe once every 2 or 3 runs. ive confirmed its not a cutting load issue as it does it with no work piece on the table as well.

i had the thing tuned rather well, and its NEVER onece stalled while jogging. ive lowered the acceleration to nearly 1/2 and at first i thought it helped, but i hasnt. doesnt seem to have decreased the frequency of the stalls.

i also tried turning off the machine and restarting after the motors have cooled, thinking perhaps it was a heat issue. no help there.

to note, its only stalling in single axis moves.

as might be remembered im in 1/2 step mode due to microstepping losing steps at low speeds. my step/driection timings in the tuning panel are 0/1. the core mach frequency is 100000hz. cpu load is 60%. also mentioned in the past, im on a 19.5v psu which is just above the limit.

any thoughts on what i should try to tweak first?

i have a hunch that is could be voltage spikes in the psu dropping below the geckos limit momentarily and thus stalling the motor. no spikes show up ever on the volt meter though and i dont know if this is what would happen in this situation anyway.

ive ruined like 10 work pieces today! whaaa!

its ok, was just scraps of pine.

[ger21]

Originally Posted by ihavenofish as might be remembered im in 1/2 step mode due to microstepping losing steps at low speeds. my step/driection timings in the tuning panel are 0/1. the core mach frequency is 100000hz. cpu load is 60%. also mentioned in the past, im on a 19.5v psu which is just above the limit.

You mean Sherline mode? Set the kernel speed to 25,000, and the pulse widths to 2 and 2. Although I'm not sure if those matter in Sherline mode.
After changing the Kernel Speed, close and restart, then re-tune the motors, then close and restart again before testing.

[ihavenofish]

Originally Posted by ger21 You mean Sherline mode? Set the kernel speed to 25,000, and the pulse widths to 2 and 2. Although I'm not sure if those matter in Sherline mode. After changing the Kernel Speed, close and restart, then re-tune the motors, then close and restart again before testing.

i believe ive tried that, but i should probaly poke at that again. at 25000 last time nothing worked, likewise at pulse widths higher than 0/1 bad things happened. motors would accelerate then stall. the thing that confuses me is that i can never get it to stall jogging. its also odd that it only stalls while going a constant speed. its not during acceleration or direction change. its never stalled in a circle operation, only a line.

ill give all the core clock setting and pulse width combinations a try tonight. ill post the results.

[ger21]

Try up to 10 and 10 on the pulse widths too.

[ihavenofish]

Originally Posted by ger21 Try up to 10 and 10 on the pulse widths too.

so where do i send the cookies?



2 and 2, and 25k helped, but still stalled. 45k a 99% fixed. 65k seems to not stall anymore, ran several cycles.

it seems theres a compromise between core clock, pulse widths and accelerations. whats ive got right now is pretty acceptable for this little mill now. it probably didnt stall in jog mode because the pulse stream in interupted every second ro so.

thanks alot!
also, i noticed that the cpu usage was actually my webcam software. didnt seem to be what was interfering with mach, but im moving it to another pc. its a camera inside the mill enclosure.


now if only i could get the pwm working

[dmauch]

Why are you in the sherline mode? You shouldn't need to be in that mode with the G540. Also I would reduce the kernel speed to 25K or 35K. You should have 40,000 steps per unit. I would set acceleration to 1 and pulses width for 5 and 5.
Have you tried the xml file that is on the geckodrive web site?
Last you may be having issues with something else running in windows. D/l the optimization file from the machsupport.com d/l page and implement the settings recommended.

Dan
dmauch@camtronics-cnc.com
low cost cases for the G540 and other fine gecko products
www.camtronics-cnc.com

Originally Posted by ihavenofish i believe ive tried that, but i should probaly poke at that again. at 25000 last time nothing worked, likewise at pulse widths higher than 0/1 bad things happened. motors would accelerate then stall. the thing that confuses me is that i can never get it to stall jogging. its also odd that it only stalls while going a constant speed. its not during acceleration or direction change. its never stalled in a circle operation, only a line. ill give all the core clock setting and pulse width combinations a try tonight. ill post the results.

[ihavenofish]

Originally Posted by dmauch Why are you in the sherline mode? You shouldn't need to be in that mode with the G540. Also I would reduce the kernel speed to 25K or 35K. You should have 40,000 steps per unit. I would set acceleration to 1 and pulses width for 5 and 5. Have you tried the xml file that is on the geckodrive web site? Last you may be having issues with something else running in windows. D/l the optimization file from the machsupport.com d/l page and implement the settings recommended. Dan dmauch@camtronics-cnc.com low cost cases for the G540 and other fine gecko products www.camtronics-cnc.com

i have 12800 steps per unit on 4mm pitch screws - this is compensated in sherline mode aparently, as in you dont need to change the steps per unit going from sherline to microstep modes. top speed is 100ipm due to the 19v psu, and acceleration is at 40 - used to be 50.

i think theres several combinations of settings that can work, but the lower clore clocks were not doing it for me. what its on right now is working, so ill leave it at that. microstep mode behaves somewhat differently, but i cant use it so its irrelevant at this point.

microstepping on the g540 is not working due to some hardware issue on the drives. the issue hasnt been solved other than by returning the unit which aparently doesnt guarantee anything either. since sherline mode works, and doesnt result in any lost of precision or bad motor resonance, ill just keep it there.

i might look into the setting again later. right now i gots things to cut!

[ger21]

I think the hardware issues are in your PC, not the drives. 25Khz mode should work fine. As for Sherline mode, quite a few users can't get their G540's to work without using it. Most likely due to parallel port irregularities.

[ihavenofish]

Originally Posted by ger21 I think the hardware issues are in your PC, not the drives. 25Khz mode should work fine. As for Sherline mode, quite a few users can't get their G540's to work without using it. Most likely due to parallel port irregularities.

im sure the stalling in pc induced, thats obvious now. my machine just happens to like the settings ive arrived at.

the sherline mode thing is specific to the drives. if i for example swap the x and y drives, the issues "follow" the bad drive. the issue is somewhat variable and only creeps up between 0 and 1 ipm. so you dont see it jogging, but you see it in the tangent areas of arcs.