Drum Drilling

I used cardboard in the past as a template...the free USPS flat rate boxes work good, he he.

If you have a drill press it should be easy enough to do.

If you have some scrap sheet metal use that as a template once its right, cardboard is easier to work with but sometimes gets off a bit.

In the 70-80's doing the job as cheap as possible was the name of the game.