Tuesday, October 18, 2005
Removing floppy steppers
Having survived a brief but rapid descent down the side of the Waitakere ranges with only minor injuries, I've replaced the stepper motor on the horizontal thread drive with a much bigger one that has a 7.5 degree step size. I now have more resolution than I can handle on that axis, and it runs much quieter.
I found that a 50mm length of 2mm i/d PVC plastic tubing, as used in irrigation and hydroponics systems, fits smoothly over the stepper motor shafts. This slips into a piece of 4mm i/d PVC tubing that has been screwed onto the end of the M5 threaded rod. This gives a smoothly rotating drive without going to the hassle of having to line up the motor and the rod precisely. I'd used the same materials before, but only as shim rather than as a flexible coupling.
It's much quieter and more reliable now - no skipping even under heavy load. I'll experiment with speeding it up, but Fire Brigade duties are getting in the way - I have to rig up some "light bars" for the celebrations in the hall, and that needs my 12V PSU as well as my time.
ECONZ Have donated heaps more connectors of the type used in Adrian's impromptu socket designs, and 200 LEDs. I can see we're getting set up for mass production in New Zealand well in advance!
Vik :v)
I found that a 50mm length of 2mm i/d PVC plastic tubing, as used in irrigation and hydroponics systems, fits smoothly over the stepper motor shafts. This slips into a piece of 4mm i/d PVC tubing that has been screwed onto the end of the M5 threaded rod. This gives a smoothly rotating drive without going to the hassle of having to line up the motor and the rod precisely. I'd used the same materials before, but only as shim rather than as a flexible coupling.
It's much quieter and more reliable now - no skipping even under heavy load. I'll experiment with speeding it up, but Fire Brigade duties are getting in the way - I have to rig up some "light bars" for the celebrations in the hall, and that needs my 12V PSU as well as my time.
ECONZ Have donated heaps more connectors of the type used in Adrian's impromptu socket designs, and 200 LEDs. I can see we're getting set up for mass production in New Zealand well in advance!
Vik :v)
