Understanding Backlash Compensation

[riv3r]

Hi

I currently have a CTC Dual and Im using it with Makerbot Desktop 3.9.

I am having some backlash issues and Im currently trying to adjust settings in the miracle.json to try and compensate for the backlash. However, I need some guidance on this.

Can anyone help me understand why is backlash compensated like this :

x% (backlashFeedback) over y mm (splitMinimumDistance) ? Why is the value not an offset of the entire print? This is causing the notches you can see from the picture above (lower left/right corner) .

1st print : backlashFeedback = 0, spliminDistance = 0.4 (default)

2nd print : backlashFeedback = 0.90, , spliminDistance = 0.4 (default)

3rd print : backlashFeedback = 0.98, , spliminDistance = 0.4 (default)

And as you can see, Im still not getting anywhere near a round circle.

[SEngineering]

Hey Kent, I’ve not played with backlash compensation on my CTC dual because I found there was almost none once belts were tensioned. However, what was definitely amis out of the box was X vs Y square alignment ( The X carriage formed a parallelogram with respect to the Y). I would definitely check that and verify belt tension before messing with backlash compensation. FWIW, of my 5 current printers the CTC routinely puts out some of the cleanest, most accurate prints (after correcting the sloppy, factory assembly and adding pillow blocks to the Y drive rods ).

[adamcooks]

Backlash is a mechanical issue. You can not fix a mechanical issue with software.