Use accelerometer to measure backlash

[oliof]

Hi,
now that we have input shaping, I was thinking about different use cases for the accelerometer. I mentioned homing using the knock sensor in the past, but today I thought of whether it would be possible to measure backlash with an accelerometer. That would be great.

I am aware RRF does not support backlash compensation and on average it is better to fix the mechanical problems leading to backlash, but I wanted to log this here so I can get it out of my head (-:

[tecno]

@oliof

The instrument is there, how hard can it be to have this very useful function added in future?

[oliof]

@tecno it is rarely a question of how hard, but of time and priorities. And those are not set by having a wish, no matter how dearly one wishes for it.

[zapta]

@oliof said in Use accelerometer to measure backlash:

whether it would be possible to measure backlash with an accelerometer

I wonder if any of these approaches would be practical for the tiny backlash we expect to find:

1. Move in one direction and stop. Then move a small distance in the other direction and see if it registered an acceleration bump.

2. Compare the accelerations (second integral?) in these two scenarios:
   a. Move and stop. Then move distance x in the same direction.
   b. Move and stop. Them move distance x in reversed direction.

3. Move back and force in small direction x. Increase x until some acceleration is registered.