Sacrificial drilling fixture out of OSB and a 2by4

[Frank S]

I find the best way for me to cut holes in thin materials is to clamp them between 2 pieces of wood as a sacrificial drilling fixture

In this case I need to drill 2 sized holes in the brass shim stock
First the small hole

then the large hole and drill through the stock to create the part

Since I needed multiples of what I was making in 2 sizes after making the large diameter shims
I changed the 3 1/2" hole saw out for a 2 1/8" so I could make 2" shims


Now drilling up from the bottom the 2/4 becomes the guide for the 3/4" hole saw

I then finish off by using the 3/4" hole in the shim and the 2x4 as the guide for the 2 1/8" hole saw

Large & small brass shims plus a bunch of 1/4" brass washers as an added benefit, with a couple of OSB disks thrown in for good measure