Dowel jig for 2x4 lumber (openscad file attached)

thingiverse

Doweling jig for 2x4s. Make sure your doweling jig is securely clamped in place before drilling holes into it. The example picture attached isn't the best because I used a forstner bit and the dowel holes ended up not being straight. For better results, don't use a forstner bit once the head goes through the dowel jig - the remainder of the bit is narrower in diameter and so the jig no longer acts as a guide. Use a normal drill bit instead. I used 1/2" spacers with a (5/8" outer diameter) available from Lowes https://www.lowes.com/pd/Hillman-1-2-in-x-5-8-in-Plain-Steel-Standard-SAE-Flat-Washer/3012480 for the spacers. I wouldn't use them next time, though - sometimes they would catch on my drill bit (not fun). Instead, I would look into getting some oil-embedded bronze sleeve bearings from McMaster-Carr https://www.mcmaster.com/catalog/125/1232. I attached grip tape to both sides of the neck of the dowel jig https://www.homedepot.com/p/3M-4-in-x-15-ft-Safety-Walk-Step-and-Ladder-Tread-Tape-7636NA/100211722, thinking it might help keep things from slipping. It's probably not necessary, though. You can tinker with the dimensions of my doweling jig by downloading the openscad file I uploaded - sorry I didn't spend any time cleaning up the code. I have a depth stop on my drill bit: https://www.thingiverse.com/thing:2783491.