Luthier cam clamp tips

[Daniel Rode]

I want to build a set of luthier cam clamps. They've been on my to-do list for a while and some recent videos piqued my interest again.

I'm going to try to make them mostly by hand. Since we have some real life luthiers here who probably made and used these, I thought I ask for tips before I start buying materials.

I have some 4/4 hard maple available, so that is probably what I'll use. I'll probably use 1/8" x 1" steel for the beam and spring pins rather than screws or permed nails.

UPDATE: Looking at the prices, I may use Aluminium. It's ~20% cheaper than cold finished steel. I'd have thought steel would be cheaper.

[Matt Knights]

Subscribe to Paul Sellers Woodworking Masterclasses, he is doing a free series on them at the moment all made by hand. And its free.

Matt

[george wilson]

I have made at least 48 cam clamps. The first batch I made in the 1960's had aluminum bars about 1/4" x 1 1/4",because I had it laying around. The clamps were made of cherry and worked fine,though a harder wood for the cams would have been better. I advise you to not use too small a cross section of aluminum,as it might bend under clamping pressure. I'd use a minimum of 1/8" x 1" bar if I were you. And,there are different aluminum alloys,too,so be careful. I recommend at least 6061 aluminum.

The 2nd. bunch I made in the 1970's out of beech wood with steel bars. These had an 8" deep throat,which proved to be much more than I needed. But,good for putting in the sound hole and clamping bridges with. The steel bars are 1/8" thick and about 3/4" wide. I just sheared the strips off of black iron plate they were always using in the maintenance area. Lots of scrap laying around that had already been paid for. These clamps work fine too. But,when you get 24 of those clamps all the way around a mold with a guitar body in it,it gets MIGHTY heavy. I had to hold the mold at arms' length and turn the assembly over. I'm getting too old for that any more! So now I just use those little black 6" plastic clamps that you squeeze the grip on till the clamp tightens. Perfectly adequate and more for clamping guitars together. The mold is much more compact,so I don't have to hold it at arms' length to flip it.

The old Spanish makers used to just use twine to clamp their sides to the top and back. It works quite well. When I was in the 18th. C. shop,I used that method. The twine was better for clamping vaulted backs,and gentle. And,you could very accurately place it if a little gap remained after applying the twine.

[Daniel Rode]

Thanks, George. I priced 3/16" x 1" 6061 versus cold formed steel bar of the same size. However, 1/8" x 3/4" steel ought to be about the same price as the larger 6061. I guess it's a wash for cost. Aluminum is lighter and easier to work, and if yours lasted since the 60s, it seems durable enough for my needs