Find Home Fails

Repeat of an earlier post with some additional info - which was automatically closed after 14 days.

After two years of no issues, the ‘find home’ button fails. Our farmbot (Genesis v1.6) finds home for the y and z axis perfectly fine. For the x-axis, it moves to the home position, slows down just before getting there, stops at the stop, moves out a bit and … moves back towards home, bumps into the stop again, but this time motors keep running full force … Giving us an e-stop as the only option. Both the encoder and motor x position keep moving into the negative until e-stop. Max missed steps is set to 5.

We have played with some settings, (using encoders/not using them, resetting x-position to 0, not allowing negative values for x etc) but the behaviour seems to persist through all of it.

I have checked cable connections and all seems good. Regular move commands like move from x=1000 to X=500 work fine.

The homing is an issue as when the bot looses power and boots up again, it does a homing sequence and runs into this issue. We do loose power every now and then, so I have found the bot bumping into the endstop and noisily keep trying to get past it when I came to school in the morning. It might have been in that state for some time.

Perhaps anyone can give a tip on how to troubleshoot this further. Could it be a mechanical/sensory issue, rather than a setting issue?

Ok. There is a lot to process here but not a lot of information.

First step is - Did you change anything near the time that the issue first came up?
Over 80 % of my issues have been self inflected. Doh!

If it was me I would… (Not telling you what to do)
1 - Establish if the X motor is moving the the correct direction when using manual control
2 - Establish if the X coordinates are representing correctly as in both positive
3 - Establish if the X encoder is still working.
4 - Establish if the belt on the X motor is still facing the right way (A twist will cause issues)
5 - Get some screen shots from my.farm.bot and share them here to prove the values are correct
6 - Get some screen shots of the settings screen so the settings can be validated.

Then
1 - Disconnect the second X motor
2 - Swap the X and Y motor and encoders
3 - Reconfigure the bed size to ensure the FB knows what the new bed looks like
4 - Run some movement tests and see where you go from there

I have had
-a reversed X axis - My own fault - twisted belt
-a negative X axis - Not sure how I did this one
-a failing X axis - When I wrote a soak test script, I hit the thermal limits of the stepper motor drivers - which I fixed by adding a heatsink
-a failing X axis as the X2 motor was skipping causing the gantry to twist - No encoder means it is not detected - Fixed by adding a heat sink (see above)

If you do consider swapping the X and Y motor, be VERY CAREFUL and look at the wiring and connection instructions. Also recognise that the gantry may twist with only one motor running.

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