I found plans online (by Bruce Matthews) for a block plane that utilizes a razor blade. I've wanted to design something like this for sometime, but this took all the work out of it!
I made a hole for a 4-40 x3/4 screw, but you can drill it out to what you have on hand. The adjuster holes have been changed from circles (In the photo) to diamonds to print better in the orientation i've uploaded. It prints without support but I'd use a brim to be on the safe side.
The razor should be adjusted to barely poke through the slot. Ive shaved plastic, cardboard, balsa, and poplar with mine. Its a good hobby and craft plane.