jig and clamp setup

[jim simpson]

I made a jig out of plywood to hold the sides in shape in order for the top to line up. The top plate doesn't have much extra material for error so alignment was more critical. Then it occurred to me that I could drill and run my carriage bolts through the strandboard base to attach my spool clamps. I have a lot of work to do on this one yet but wanted to get the jig work out of the way. I call this the Dude project as the top was made by Lynn Dudenbostel.

[fscotte]

Have you tried making a form for your rim to sit in?

[John Kelly]

Good idea there. I have made clamps exaclty like yours, Jim. I used the same rod and wing nuts and sliced up a broom handle in the bandsaw to make the wooden spools. I also added cork washers to the clamping faces of the spools to protect the soft soundboard wood when clamping it.
Making a from, as suggested by fscotte, is a good idea and will make it easier to keep the sides vertical during the process of joining sides to top (and back).

[Earl]

I might be mistaken, but I think the dark plywood in the photos IS an outside form. Personally I like the form to be a bit deeper though.

- Earl Tyler

[John Kelly]

I might be mistaken, but I think the dark plywood in the photos IS an outside form. Personally I like the form to be a bit deeper though.

- Earl Tyler

Earl, on looking again I see that you are correct. The ply has been cut to make a former. I can see the board beneath and the sides would be rather shallow if they were not recessed into that piece of ply.

[jim simpson]

Yes, the plywood is the form and could probably be doubled up. My original plan was to hinge it but I did a dry fit using 2 clamps to hold it together. That is when I got the idea to drill through the bottom board to create the clamps. I have leather circles cut and punched for the wood spools, sourced from old leather belts. Here's a photo of the waste from the inside of the form

[Tom Haywood]

Neat idea. How do you keep the bolts from spinning when you tighten the wing nut? I usually cut an inside form from some thick cardboard to keep the sides straight when gluing the top on.

[jim simpson]

Thanks Tom, I tightened the bolts up so the heads of the carriage bolts seated underneath into the strand board. I guess another way would be to secure the bolts at the base of the bolt with a washer and nut but that seems like overkill.