This depth stop is customizable to your current drill bit size, perfect for me who tends to figure things out as I go along. First you drill a hole using the stepped size guides, then attach it to the bit you just used. It's great to have one or two of these around especially if you're on the go and can't justify carrying a set of depth stops with you. It works with sizes up to 3/8".

Along with the depth stop you need to print the tight fitting jig, which is 100% necessary and prevents your drill from tearing the depth stop apart. Do not attempt to drill the hole while holding the depth stop in your hand. With the stop in the jig, secure it with a clamp or vise. Go slow when making the hole, I slow my drill down to its lowest setting. Once you make the hole, flip the depth stop over and drill through from the opposite side to ensure it's even. It clamps on to your bit via an M3 nut and screw (12mm minimum, 14mm recommended). You will be able to get it quite tight and secure.

I recommend the depth stop be made of ABS/ASA or PETG, with a big preference towards ABS. With PETG you'll want a very sharp bit. PLA will work fine but it's more difficult to drill cleanly. The jig can be any material, and it's made with extra walls and 25% infill. The print profile includes extra walls and a 20% infill for the depth stop - some may recommend much higher, but I've found it easier to make clean holes around 20%. If you're using a larger sized bit, I suggest drilling a smaller hole first bit then moving up to your selected size. The file contains a reduced height depth stop for use with smaller drill bits.