my sleep deprivation reaches unhealthy levels as I can’t let my fingers from my new maslow. Such a great project - really cool!
Until now everything works like a charm - my frame is sturdy as rock (I have used a piece of 150 x 80 mm aluminium truss from the scrapyard as front cross bar - very stiff!), the electronics worked flawless and despite some minor trouble when it came to calibration the software runs without fail.
But yesterday evening something odd happened: from one moment to the other the z axis got crazy: I evenly told GC to return to home coordinates and X/Y axis did as expected. But z axis kept on lowering all the way down until my router sled was fully lowered. Even then it kept on trying to get lower which resulted in skipping teeth with a heartbreaking noise in my z axis gear (I have a Makita router with a self-tinkered z axis control where I had to mount the motor upside down, transmitting its torque through two gearwheels)
I immediately stopped maslow (by pressing Stop in GC) and had a look at the coordinates the firmware reported to GC. The z axis was zero - which was obviously wrong.
I opened the z axis menu and initiated a raise by 10mm. The z axis motor started working, the sled raised, but the reported z axis position in GC remained zero. Since the z axis kept on raising with a somehow uneasy running motor I stopped it manually via GC z axis panel.
I then tested the motors via GC-Actions->Test Motors/Encoders and intrestingly the first test of the LEFT (!) motor turning CW failed with a whining noise from the motor. all other subsequent tests went okay, including left motor CCW and z axis motor. Now the GC reported z coordinate seemed to function again - understandably with a decalibrated z axis, but with sane encoder responses.
I started sweating in the fear of a toasted motor controller but when I started the the test motors sequence again, all tests passed and after recalibrating the z axis everything works fine again.
I checked the connections of the z axis cabling to no avail and also all other connections seem to be fine, too.
I’m using firmware/GC v1.10 with a stock arduino board and GC on Xubuntu linux 16.04. Except the z axis gears and the aluminium mono crossbar my setup is pretty similar to the standard maslow setup.
I don’t know what happened here but I don’t like to go through this again. The skipping teeths and the whining motors are really frightening noises. So my questions are:
- what could have possibly went wrong?
- what could I have possibly done wrong?
- what could the test motors/encoders sequence ‘repair’ automatically (as so it seemed to do)
And I have a feature request:
- is it possible to implement automatic damage prevention by stopping all motors if the encoders don’t report any movement for a certain amount of time even though the motors are advised to run?