Drum and base
To do some testing on a Stepper Motor evaluation kit from Trinamic, I’ve been building a test rig. The idea is that the motor will drive a slider and I’ll check the position of that to determine the repeatability of the motion. The motor also has an optical sensor so it will be possible to tell if it is skipping steps.
The base of the test rig is a long aluminium beam I salvaged when the office did a refurb. I remember taking that home on the London underground. It was standing up and I was holding it. An old man got on and thought it was a hand hold so also took hold of it. He got a bit of a shock when I wobbled it.
I made some T-Nuts from some captive nuts that are designed to be pressed into wood. I filed off the spikes and filed them to size so they would slide down the slots in the track.
Those nuts attach the brackets for mounting the motor and a pillow block bearing. I used the drill press to press a short length of steel bar into the bearing.
The cord to drive the slider will be wrapped around a drum. As the stepper has a flat on one side, I designed the drum with a slot. A small section of steel is pushed into this to lock the spindle to the drum.
Whilst I’m waiting on my cord to be delivered, the next job is a simple slider / pointer.