Stalling Motors

Hi all. First I’d like to say what a great project, thanks to all who put in the work!

I’ve built the picam v2 microscope using the standard 5V stepper motors. I find the motors often stall and fail to move the stage or focus when supplied with just 5V. Is this a common problem? Should I try 12V motors?

Perhaps my stage is starting off non centred which is putting excess strain in certain travel directions. I’m having difficulty understanding how to centre the stage, is there any documentation regarding initialising the stage?


The 5V motors should be fine, but if you are at the end of the travel then they will stall. There is no automatic way to centre the stage, but it should only need to be done once. I find it is easiest to unscrew the motors and then turn the knobs by hand. The stage is centred in x-y when the legs are upright, the nut slots in the actuator legs will also line up with the holes in the actuator body. Of course it is possible to do this movement using teh motors, but I find it hard to think whether it is + or - steps and how far, so I just do it by hand.
Once you have the stage centred and the motors on, then you should reset the motor counts in the webapp to zero - there is a button in the navigate tab. The motors remember their motion even after shutting down, so once this zero is set you can re centre the stage by entering position 0,0,0 in the navigate tab and pressing move.

Thanks for the information, I’ve followed the centering instructions you suggested and they worked well so it now appears to be an issue with lack of movement in the negative X and Y direction as described in the “Restricted Actuator Movement” thread and not an issue with the 5V motors.