Backlash issues.

[Anton]

Hi, all.

Today I have assembled  X and Y axes of my X2 mill with cncfusion ballscrew upgrade kit and after a first run I have measured a backlash in it.
Then a I tried to switch on a backlash compensation in Mach3, but nothing happens. Compensation, tested with G1 commands, does not work.
Of course I have restarted Mach3 after switching compensation on.
I'm using Mach3 3.042.018 and SS board Beta2_v015me.
Does it exactly a SS plugin issue or I'm doing something wrong in setting up Mach3?

Best regards,
Anton.

[Hood]

The SS doesn't support backlash comp yet, think its next on the list to do but when I dont know.
Hood

[Anton]

What a pity...
So, a have to rollback to PP, but still waiting for a backlash comensation.

Anton.

[Hood]

How big is the backlash, if its new balscrews it shouldnt be much even if they are just rolled.
Hood

[Anton]

Backlash is between 0.07 to 0.15 mm depending of the load. 

[Hood]

That doesnt sound like backlash, more like flex in your bearing mounts or ballnut mounts. I dont think backlash would increase with pressure. If it is flex then dont really think backlash comp would help much.
Hood

[Anton]

Without a load at all, backlash in ballnut is near 0.07mm, so it is not a flextire. Other is a flexture of the ballnut mounts, so after a precision adjustment a have a final backlash on X-Y around of 0.07mm

[Hood]

seems quite a lot for ballscrews, are they new?
Hood

[RICH]

What make model etc. ballscrews did you buy.
If you don't get a preloaded ballscrew nut then that kind of backlash with a rolled screw would not be out
line. You can use two cheaper nuts with mounting to a piece in between such that you can put a load on them
and take out the nut backlash. Not the ideal and that is what some people are selling out their for their cnc machines.
With that you may loose some axis travel.

So until the SS gets backlash implemented no joy ( your postinig is right above mine on the site ) .
Hopefully it will not be to much longer. I have been waiting for about 5 months now for it to be implemented.
RICH



 

[Anton]

What make model etc. ballscrews did you buy.

I have bought a cncfusion X2 ballscrew upgrade kit with Thompson screws, preloaded ballnuts and a zero backlash helical couplings. The screws themselves seems no be new.