Backlash compensation causing stalling

[sopac]

Hello, I have measured .004 backlash on my Y axis and am trying to use mach3 backlash compensation to correct for it.

but when the Y axis takes up any backlash it causes any other axis in motion to stall.

here is some info on my setup:

P4 2.4ghz HT
1 gig ram
1/8step driver
24000khz kernel speed

I have been able to track the problem down to the shuttle accel which was set at .005, when i changed to .5 it would fix the problem, but cause the other axis to come to a complete stop and then accelerate again when the Y axis took up backlash.

I dont see why backlash compenstation on 1 axis should effect the others.

I have tried different kernel speeds and everything else I can think of.

any help would be greatly appreciated.

Josh

[holbieone]

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[holbieone]

it has too

to maintain the correct cutter location it has to stop the other axis until the axis being adjusted is into position
other wise the geometry being cut will be violated bay the cutter


maybe you tune it so it makes the adjustments quicker ?

[ger21]

Hoss has a video on YouTube that explains how to set it correctly.

[sopac]

That makes sence, but in that case why doesnt it follow the parameters set in the motor tuning for accel times?

each axis has diffent accel times and the shuttle accel applies to all.

[sopac]

Originally Posted by ger21 Hoss has a video on YouTube that explains how to set it correctly.

Following Hoss' instuctions causes it to stall the steppers.

[ger21]

Did you change the backlash speed in addition to the shuttle setting?

[sopac]

Yes, backlash speed 100%
shutter accel .005

stalls x and z axis when y is taking up backlash.

[ger21]

Did you try lowering to maybe 50%? It stalls because it's going too fast.

[sopac]

I can get it to stop stalling by reducing the max velocity on the X and Z axis by 50%, but everytime the Y axis takes up backlash the other axis in motion do a violent jerk that cant be good. I got my backlash down to .002 and I think im going to have to live with it.

[finsel]

Hi sopac,

I don't know if this video can help you.. anyway take a look.

YouTube - Mach 3 Backlash Compensation
Tks!
Frank