Doing a jig

I've been using the Kreg K4 jig to make pocket holes recently. I'm pretty new to using such a jig and it's worked out really well. It's easy enough for our woodworking students to use but still challenges them to consider hole placement, depth and final appearances when filling with dowels or putty. Unfortunately, the K4 is quite expensive at around $130 regular price. There are cheaper versions, but they typically require clamping and move around a lot.

Since we typically have 15 students all requiring the jig at the same time I tried shopping around for cheaper version. I turned to Thingiverse and found a few different jigs. I printed out this one and found some 1/4" copper couplings at Home Depot to insert. The couplings should help guide the drill bit and protect the plastic from damage, similar to how the Kreg jigs work. I'd like to attach a vertical support on either end to help with clamping and alignment.

For the drill bits, I ordered some 3/8" bits with stop collars from Amazon. The reviews are a bit mixed on the durability and quality of the step screws on the collars but for $11 each I'll give it a try. I'll have a total of 6 3D printed jigs, 4 extra drill bits, the Kreg K4 and a smaller R3 jig. My 3D printed versions and Amazon drill bits are basically DIY versions of the Kreg Jig Mini sold for around $27. Plastic filament works out to be about $1.50, drill bits and stop collars were $11, and the copper couplings were $1.15 each. So a total savings of about $14 each, or $56 in total. We'll see if they work!