Setting up a New Faceting Machine and Faceting Laps
When many people set up their machine for the first time, they experience a frightening situation. I know this happened with me.
The arbor hole on Crystalite laps is 1/2". The arbor spindle on most faceting machines is also 1/2". This sounds good in theory, but it doesn't allow for enough clearance to put the lap on, and especially to take the laps off. This annoying spindle-to-arbor-hole problem is especially common on Ultra Tec and Poly-Metric machines, but has also been experienced with Graves, Lee and MDR machines.
The solution is simple. You can either slightly ream out the arbor hole on the laps with a fine round file or sand down the spindle on the machine with silicon carbide sanding paper. I opted for the latter solution, so any new laps I bought would immediately fit my machine.
If you opt for the spindle sanding solution, go to the hardware store and get a paint stirring stick and one sheet of each grit of the following sandpaper: 180, 400, 600, & 1500 or 2000. Wrap the 180 grit sandpaper with the grit side facing out around the paint stick. Turn the machine on and press the end of the paint stick against the arbor spindle. Move the stick up and down the arbor, but concentrate mostly on the bottom of the spindle. When both sides of the sandpaper wear out, pull the sandpaper off the stick and replace it with the opposite end of the sandpaper at the business end of the stick. When this end of the sandpaper wears out, cut off the worn area and carry on.
Check the laps to see if they slide on and off easily. Don't let the lap drop all the way on to the arbor spindle until you are sure that it will slip off easily. They tend to anchor themselves at the bottom and are frightfully hard to get off. Once the laps fit on and off the arbor smoothly, use the 400, 600 and finest grits to remove the scratches from the previous grit. I keep the arbor spindle on my machine slightly lubricated with white grease or vaseline to facilitate easy removal of laps.