Woodworking Clamping Cauls

Keeping boards flat is nearly always a problem when glueing together. There are many ways to make cauls, this is mine. They are good for up to 27". 

Hardware: The super strut I used came from Home Depot for around $30 per 10' piece. Cut into four pieces makes two complete clamps. Also needed are four ½-13 x 5" carriage bolts, four ½-13 nuts, four washers (I used 7/16 that had an actual ½" hole). 

Printed Pieces: End caps, since the formed strut can vary these caps will not fit tightly. Use an adhesive to set them in place. Straps, they keep the bolts in place and makes it easier to work with glue ups. They clip in and have an extended tag on the ends to snap out. They are thin so print extras and use a raft and 100% infill. Feet, they quarter turn in the strut to keep cauls from falling over. Turn Knobs, the nuts should press in without adhesive, they are gusseted for strength but still don't crank down to tight, it's still plastic. I included a nut test stl file for proper fit. The washer goes under the knob for easier turning and not scraping on the strut.

Printed on Ender 3 with PEI plate, 0.20-layers, 3 walls, infill 25. My inspiration to make this came from a YouTube video. (2) Rockler doesn't want you to see this video - YouTube