[school sweeper]

I setup my mill , 3 axis , using linuxcnc step config program.

step time 10k
step space 10k
Dir hold 20k
Dir setup 20k
jitter 14300

motor step per rotation 400 , micro step 2 , 1 to 1 , 10 leadpitch , max vel 10 mac accel 30. When I test it and when I run short programs my x , y , z all only go 1/2 the distance.
I set 10" it only goes 5" , I set 2.5" it only goes 1.25" on and on and on. kl4030 , 425oz , c10 BOB . It works but it only goes 1/2 the distance. I have tried several combinations
for microstep and anything else that might fix the problem.But I have hit a wall.

If anybody has any ideas and or suggestions. I am all ears!

[wendtmk]

Are you sure your motors are really 400 steps per revolution? Most steppers are usually 200 steps per revolution. If that's the case, it would explain why the axis movement is 1/2 what it should be.

Mark

[school sweeper]

You sir are correct, my steppers and the driver are 200 steps per rotation. To be honest this is driving me a little bats. Original setup the settings were at 200 steps per rotation.. but I was getting only about 1/4 of movement.Every chance I get to run it and do the measurements I was getting 1/4 movement. So last night I rechecked all my settings the threads on my lead screw are 10tpi, I scoured ever bit of information I had and it was the same. I have a DRO connected so I can see the true distance travel , makes it nice. I also place a ruler down so I can watch . I started to tweak the numbers just to see what would happen I changed the steps from to 200 to 400 and the distance traveled actually doubled. Even then it measured out as only 1/2. on the program read out it went the distance but true measurement was only 1/4 and 1/2 respectively. Also the program read out shows that it made 8000 steps per rotation. While typeing this I had a thought, my controllers are set for 1/8 step . But when programmed in at 1/8 the steppers freeze. But the setup keling informs is 1/8 would that make a differance?

[wendtmk]

Check and make sure the microstep settings on your drivers match what you've got set up in the stepper config. If it's not the steps per revolution, it may be that your not actually micro stepping at all. Check your DIP switch settings on the drivers.

Is it just one axis doing this, or all axes?

Mark

[school sweeper]

Thank you for the fast turn around! I went in and did the edit put everything back to the norm turns to 200 , and then microstep at 8. Tried the jog and it made lots of noise but the only movement was from tapping the jog. The drive froze , I tried a small test area with the same results. The program readout said that there was 16000 steps per inch which if it had really moved would have been correct. But no movement. The setting on the driver is for 1/8 step. And yes unfortunately it is for all axis! If you are familiar with linuxcnc stepconfig then you know which setting I am working with. I have tried the step settings before and it seems that it only works in 1/2. erratic in 1/4 any ideas as to what I need to be looking for. Heaven forbid if I have to change computers!

Harvey Johnson

[PCW_MESA]

I setup my mill , 3 axis , using linuxcnc step config program.

step time 10k
step space 10k
Dir hold 20k
Dir setup 20k
jitter 14300

motor step per rotation 400 , micro step 2 , 1 to 1 , 10 leadpitch , max vel 10 mac accel 30. When I test it and when I run short programs my x , y , z all only go 1/2 the distance.
I set 10" it only goes 5" , I set 2.5" it only goes 1.25" on and on and on. kl4030 , 425oz , c10 BOB . It works but it only goes 1/2 the distance. I have tried several combinations
for microstep and anything else that might fix the problem.But I have hit a wall.

If anybody has any ideas and or suggestions. I am all ears!

When you change the microstep ratio you also change the maximum velocity and acceleration.
My guess is that when you select the (correct) 8 to 1 microstep ratio, you exceed the acceleration
abilities of your drives/motors. I would leave the microstep ratio at 8 to 1 and then
try lowering the acceleration by a factor of a least 2 and see what happens...

[school sweeper]

Well I am perplexed to say the least. Default in Linuxcnc for acceleration is 30 , I changed it to 15 then to 10. The default in linuxcnc for the microstep is 2 I changed it to 4 and 8 (it froze at 8) the default for steps per turn is 200 and I have changed it to 400 (at which point it doubles my distance travelled which at this point is actually 50%) The default for lead-screw thread per inch is 20 I changed it to 10 tpi because that is actually what it is. I have tried changing all of these settings in every combination I can think of at the time and sometimes the motors freeze and sometimes they work great. But i can not achieve the distance travelled that is programmed in. it is always either 1/4 or 1/2 of the desired distance. Any ideas , I am open to anything!

[PCW_MESA]

Well I am perplexed to say the least. Default in Linuxcnc for acceleration is 30 , I changed it to 15 then to 10. The default in linuxcnc for the microstep is 2 I changed it to 4 and 8 (it froze at 8) the default for steps per turn is 200 and I have changed it to 400 (at which point it doubles my distance travelled which at this point is actually 50%) The default for lead-screw thread per inch is 20 I changed it to 10 tpi because that is actually what it is. I have tried changing all of these settings in every combination I can think of at the time and sometimes the motors freeze and sometimes they work great. But i can not achieve the distance travelled that is programmed in. it is always either 1/4 or 1/2 of the desired distance. Any ideas , I am open to anything!

Still sounds like your steppers are stalling due to to high acceleration or velocity

An acceleration of10 IPS per second may still be too fast , (Try 5 or lower)
and you may also need to lower your maximum velocity as well to avoid stalling

[school sweeper]

eureka! Sirs I owe you ALL a debt of gratitude. The thorn in my side has been removed it has been a steep learning curve but success.

Final settings 200 steps per rotation, 1/8 microstep , max velocity is .5 IPS , max acceleration is 2 IPS works like a charm on all three axis.

Thanks Thanks Thanks!

[wendtmk]

All right! Glad you got 'er workin'!

Mark