This is an attachment for a dremel or similar tool that makes it easy to grind tungsten electrodes for TIG welding.
It has holes for 1/16", 3/32" and 1/8" electrodes at 4 different angles.
It uses a diamond disc that I got at harbor freight (I think)
Thanks to Lenbok ( http://www.thingiverse.com/Lenbok ) for the original design. I'd been meaning to design this for a while but his design did most of the work for me.
Print it out.
There are now two versions of the file, one is a little larger than the other to fit a 45mm diameter grinding wheel.
If the holes are a little small you can enlarge them either by sticking a hot electrode through them or with a drill bit.
Put the diamond disc and arbor inside the attachment so that the arbor is sticking out the threaded end.
Put the arbor in the collet and tighten it and then thread the attachment onto the nose of the tool.
Turn it on, put the electrode in the appropriate hole and sharpen it.
Be careful that the electrode doesn't get too hot and melt the plastic.