Bench testing trigger wheel

[Spudmn]

The following is how I turned an old hard drive into a missing tooth trigger wheel for bench testing. I was lucky enough to have some very old hard drives in storage. These drives are so old that they use a very fine stepper motors to move the head. I kept them for the stepper motors but the spindle motor had a VR on it and I thought that with a few modifications I could turn it in to a missing tooth trigger wheel.
The spindle motor already had one indentation drilled so I needed to add 6 more to make 8-1 trigger wheel.




I printed out a template on to a sticker so that I could centre punch the location of the indentations.



Next I taped up the opening of the motor. I didn't do this the first time and the metal swarf got under the motor and jammed up the movement.



I then drilled the indentations.



I put the motor back into the housing and wired it up.



You can spin the motor by hand or use a drill to drive it.



I might be hard to find a hard drive like the one I used. You may be able to use a newer hard drive and glue small magnets on the platter to make the teeth.

[Fred]

Awesome!

Any reason why you didn't keep the motor that drove the original disk and voltage control it or pwm it or something?

I don't think I've even seen a disk like that one before, well, maybe in the history section of UoA compsci :-)

Fred.