Handscrew: from WoodCentral
As this thread shows, sometimes it only takes one person who is conversant on a subject to provide just the answer you are looking for. – Editor
“How do I build a handscrew? I'd like to make a small handscrew type clamp to use for holding small parts on the router table. Four cross dowel bolts, two pieces of wood, and two threaded rods. It looks like a simple device to make, but something just isn't right. What makes the jaws move? Are two of the bolts supposed to be reverse threaded or something? This has me baffled.” – Tom
Actually, he knew the answer: the bolts are reverse threaded. He just needed confirmation, and he got it, along with an in-depth explanation of the difference between new handscrews and the old type made entirely of wood. He also learned how the new mechanism makes them more versatile. – Editor
“Modern handscrews use ‘turnbuckle technology,’ with all the cross dowels threaded and the two ends of the spindles threaded in opposing directions. It used to be possible to get kits for making handscrews - you might troll through the various mail order house online catalogs to see if these are still sold. Old wood thread handscrews worked differently. The end screw, farthest from the clamping end, was threaded into the first jaw it touched, and the end of that spindle was turned down a bit to fit into a blind hole on the second jaw, to push against the jaw. The middle screw passed through a clearance hole in the first jaw it touched and was threaded through the second jaw. Thus, the end screw served to create a fulcrum against which the middle screw was working. The wood-screw handscrews depended on the mechanic knowing that the jaws needed to stay as close to parallel as possible. I suspect the flex inherent in a wood screw permitted a little lack of parallel, but I recollect an older intro-to-woodworking book that warned against getting the jaws too far out of parallel and had a graphic drawing of the rear screw cracking over its length, intended to strike terror into the apprentice's heart.” – Bill
Square Boxes: from Sawmill Creek
“I'm planning on making a whole bunch of boxes soon, most of which will be a foot along all dimensions. I have no corner clamps, and was wondering if any of you had any quick solutions for keeping the boxes square during glue-up, other than ‘go buy corner clamps’ of course.” – Howard
There were some quick, simple ideas to keep the boxes square. – Editor
“Make them with a square bottom that slides in like a drawer bottom.” – Brian
“Make a piece of plywood with 2x4s screwed to it in a 90 degree pattern. Place the box on the plywood and clamp to the 2x4s while gluing.” – David
“I made a few this weekend and used an ordinary band clamp. Once I got them pretty snug, I just measured diagonals. If they were off, I hit it with a mallet, and the band clamps seemed to keep everything from moving again.” – Barry
“You can also purchase wide rubber bands that work very well for smaller boxes.” – Jim
One fairly elaborate suggestion called for tape instead of clamps. – Editor
“I usually use blue masking tape for mitered corner boxes. Lay the four sides down on a flat surface. Attach tape firmly to first side, and with the mitered edges tightly together, stretch the tape and attach to the second piece. Ensure the tape is firmly rubbed down. Continue this process until three of the corners are taped. Carefully turn the pieces over so the inside is facing up and insert your bottom and, if applicable, top pieces. To test, just fold the sides up into a rectangle. You may have to use a little pressure to force the last joint together but if you attached the tape firmly, the other joints won't pop apart. If everything fits ok, unfold the pieces, apply a light coat of glue to all mitered edges, then let it dry to 10-15 minutes. Apply a second coat of glue, insert the top and bottom pieces, fold the box up, then apply tape across the last joint. Let sit overnight for good drying.” – Jim