April 10, 2016
Description
This is a sander made for a 30mm diameter, 2.3mm shaft Hobby DC motor as commonly found in old inkjet printers (this one was from an HP I think).
Probably totally useless, I just got an idea and had to make it, it seems to work, for how many minutes I don't know :-)). Maybe useful for sanding 3d prints, or blank PCB material ready for toner or UV film lamination.
There are just a few parts, the bottom foot (Part 1), the upper motor shoe (Part 2), two top plates which hold the foot to the shoe (parts 3 and 4) and a cam wheel (part 5).
The cam wheel should be printed (well, I think it should) with a heavy infill, I used 60%.
The cam and the receptacle for it in the foot should be coated with epoxy (or maybe super glue). Apply liberal grease (vaseline probably would do) to the cam receptacle and the top surface of the foot.
Insert 5 M4 pan head screws from the bottom of the foot, up through the shoe, and screw into the mounting plates. Do not screw tightly, the mounting plates should float loosely, they are just to stop the screws from falling out. However they must be screwed in far enough that the screw heads are fully inside the foot.
Fit the cam wheel onto the motor shaft, you may need to drill the off-centre hole out a bit. Grease the cam wheel also.
Insert the motor into the holder seating the cam wheel into it's receptacle, don't push it all the way down make sure that the foot can "float" slightly up/down, it's a loose fit.
Use 2 M3 pan head screws and nuts to tighten the motor mount (depending on how strong your print is, reinforcing the base of the motor mount arms with epoxy may be necessary).
For attaching sandpaper, I originally intended to use a rubber band around the edge of the foot, but I will probably just use glue-stick and glue a cut-out bit of sandpaper to the bottom (I have not tried sanding with this yet).
This was made n OnShape, it's a public document you can copy and edit to your requirements:
https://cad.onshape.com/documents/553d9985e4c1f9ab53e855c2/w/4f5669efeed1fc1d019b57f7
PS: Sketch 1 is where you'll find the motor diameter
License:
Creative Commons - Attribution
sleemanj
