Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2927332.
This is a 1/4" doweling jig that I created to help me through a project build. It was designed to work on 3/4" plywood or MDF, but I'm sure you can easily change that. I looked into commercially made jigs but they were all too expensive. So I decided to print my own!
You will need the following from the big box store, or off the interwebs (your choice): 2 - #6 x 1" machine screws 2 - #6 hex nuts 1 - 3/8" OD x 1/4" ID x 1/2" long metal spacer/bushing (steel or bronze should work)
I printed mine with the sides that would be facing the inside of the jig on the bed as to have them as flat as possible. The spacer should be a nice, tight press fit, but if it's loose, super glue should help do the trick. Once assembled, use a your 1/4" drill bit to finish drilling the hole in the dill plate. Then use a knife or the like to clean up the tear out. Done.
Hope you guys find this useful. It worked great for me and saved me about $60! Enjoy!