Wednesday, May 22, 2024
Direct Drive Woes
I've been trying to put a direct drive M3 threaded rod on a stepper motor to drive the microscope mechanism directly. This is not working out well. The reason being that the axis of the motor and the axis of the screw hardly ever line up, causing the threaded rod to rotate in small circles. With the geared drive in the OpenFlexure microscope, the gears allow the motor shaft and M3 screw to not be exactly parallel, and the flexure mechanism halts the rest of the wobble. There is an incredibly large force in that wobble and it will bend and torque the most enthusiastic of flexures out of shape.
So for the moment the parallelogram mechanism goes on the back burner and I'll just have to compensate for the axis drift in software. That's probably where this will all end up anyway, once I have axis zeroing sorted out.
