Woodworking Hold Down Clamp - 3/4″&20 mm Dog Holes

A fully printable holdfast/hold down clamp for woodworking workbenches. Versions for 3/4″ (19 mm) and 20 mm dog holes available.

This is my attempt to create a 3D printable woodworking holdfast that works well enough to be usable. This version can hold down boards quite strongly on my workbench, although not as strongly as metal ones. Anyway, they work (even in PLA) and I had a lot of fun designing and tweaking them.

If you decide to try them out yourself, let me know how they work for you.

Assembly Guide

1. (Recommended). Glue a 9 mm x 70 mm strip of medium grit sandpaper (e.g. 180) to the back side of the rod piece (The one the arrow on top is pointing away from).

   

2. Slide the leaf spring part over the threads on the rod until it sits on the shoulder. Make sure it points in the direction of the arrow and the jaw is pointing downwards.

   

   

3. Insert the axle into the handle so that it's centered.

   

   

4. Insert the handle assembly into the large cantilever piece so the handle pokes out on top. If if does not fit, try changing the fit of the axle a bit.

   

   

5. Screw the rod/leaf spring-assembly into the cantilever. The screw should bottom out when all parts are in line.

   

6. (Optional) Glue a 30 mm x 30 mm piece of medium grit sandpaper onto the jaw face and trim the edges to increase the holding power. If you're clamping parts where you worry about their surface finish, skip this step.

   

Usage

To hold a work piece down, insert the holdfast into a doghole (with the handle in the upright position) until the jaw rests on the work piece. Then push down on the rear side of the holdfast (the one with the rod) with one hand and fasten the work piece by pushing down the lever in either direction. Both directions work, choose what fits you better.