Messages

1

General Mach Discussion / Re: Jerky motors on slow feed rate

« on: March 10, 2008, 04:14:56 AM »

Many thanks for the suggestions.
But yesterday I made some other tests that have been very successfull.
As I said I had very big problems on slow feed rate and not on very high. So I tried to activate the motors on HALF STEP (I was working with ENTIRE STEP and my hardware has some bridges to choose 1/2 , 1/4 and 1/8 step) and changing then step/unit to the double: everything was fine (to maintain the same mm/min the pulsing from the PC was doubled by the software).
Now, the final configuration is set to 1/8 step on the hardware and 533 step/unit (I have a 200 step/turn motor and a screw with a pitch of 3 mm) and I sounds pretty good.
I made some working simulations at the speed of 100 mm/min (the worst I had before) and then RETURN TO ZERO without evident errors.
I didn't found the cause but I solved so the problem... (well... I hope)
Many thanks for you help.

Antonio

2

General Mach Discussion / Jerky motors on slow feed rate

« on: March 07, 2008, 05:37:33 AM »

Dear friends,
I'm new in the discussion. I write from Italy and I use Mach3 version R.1.83.
I have a strange problem using slow feed rate (actually >50 and <150 mm/min and the worst is 100 mm/min).
I was afraid of high feed rate but then problem is on the contrary.
As "destructive test", I've tested my machine at 1500 mm/min with hard acceleration, jogging and working and everything is OK! No missing steps.
As I feed at 100 mm/min then motors begin jerking very evidently (even vibrating forward and backward for a while)
If I jog them in the same direction the problem is not so evident: it appears when changing direction.
I have tried everything:
new powerfull power supply, shielded cables, new computer (but the computer are PIII 650/1000 WIN 2000 newly installed, driver test really shows picks higher than the suggested), new printer cable, every possible suggestion found in the forum (backlash, slow acceleration, pulse width, I suspected even wrong GCode) but nothing.
Same problems even with the newest limited version of Mach3 downloadable from the site...
Any suggestion?
Many thanks in advance

Antonio

3

General Mach Discussion / Slow feed rate problem

« on: March 06, 2008, 03:57:55 AM »

Dear friends,
I'm new in the discussion. I write from Italy and I use Mach3 version R.1.83.
I have a strange problem using slow feed rate (actually >50 and <150 mm/min).
I was afraid of high feed rate but then problem is on the contrary.
As "destructive test", I've tested my machine at 1500 mm/min with hard acceleration, jogging and working and everything is OK! No missing steps.
As I feed at 100 mm/min then motors begin jerking very evidently (even vibrating forward and backward for a while)
I have tried everything:
new powerfull power supply, shielded cables, new computer (but the computer are PIII 650/1000 WIN 2000 newly installed, driver test really shows picks higher than the suggested), new printer cable, every possible suggestion found in the forum (backslash, slow acceleration, pulse width, I suspected even wrong GCode) but nothing.
Same problems even with the newest limited version of Mach3 downloadable from the site...
Any suggestion?
Many thanks in advance

Antonio