Backlash speed

Good morning to all,
I have Backlash setup in the ini file for my axis. Is there a way to decrease the speed on the backlash? My stepper motors jerk pretty hard when the backlash kicks in.

Thank you,
Raul

not that i am aware of ..
however , if your getting jerk , then it's proably you have the backlash set a little too far , try reducing by 2 or 4 steps ,
dont worry the stepper motors can handle it . it's more tweaking the values you have a little bit closer to ideal .

of course it's better to handle the backlash mechanicly and solve the mechanical issue long term .

Backlash is set to .01.
Will try to work on mechanical backlash but might have to purchase antibacklash ball nuts.

Thanks
Raul

what ballscrews & nuts do you have, or using at present

There are lots of places backlash can hide besides between your nut and screw. Be sure to check them all. Places like the end support bearings for the screw is a very common place for large amounts of slop. Worn and sloppy ways is another.

Cncbasher- I have Rotton ballscrews and nuts installed on my mill.


Todd- Thanks for the hints. Ill be shore to check everything to eliminate any slop.

Thanks,
Raul

I tried setting the backlash parms and got an error from pathpilot. I called tech support and they stated they don't support the backlash feature.

I know you can set BACKLASH= but as I remember it, you need to also increase the velocity so that backlash can be removed quickly.

This is where pathpilot complained on boot. It didn't like that I had increased the max velocity setting (according to linuxcnc docs) and refused to run.

You do not need to change your velocity settings to use backlash compensation

You _do_ need to change your STEPGEN_MAXACCEL settings to 1.5 to 2X
the machines axis acceleration value:

linuxcnc.org/docs/2.6/html/config/ini_co...tml#sub:AXIS-section

Yes, I know. But PathPilot will not boot with that value changed.

I said "velocity" because I didn't remember the particular value's name. The point really is, that Tormach doesn't support a lot of changes to their files. I've changed one line in an INI file and had the program insist that a re-install was required.

pathpilot shows a " re-install" popup on ANY error in the hal or ini files , this can point you in all sorts of directions other than the correct one.
take a look at the file in gcode/../../pathpilotlog.txt
this will show the actual error , once the error is fixed the re-install popup will go .