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For one recent turning project, I needed to clamp surfaces that
were 30° apart, a job beyond the ability of bar clamps,
pipe clamps, C-clamps or quick-grip clamps. To remedy the problem,
I came up with an angle clamping jig, which made a potentially
frustrating session in the shop into a routine clamping job.
You can build the jig out of scrap pieces of 3/4" plywood. The
only items I purchased were two 3/4" round bench dogs and two
3/4" round Wonder Dogs?, but even these could be shop made if
you have the right tools.
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| The "problematic" project |
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Isometric
view of the angle-clamping jig |
The Cut List
You will need
- 20" x 9" x 3/4" (1) plywood piece
for the top
- 20" x 6-1/2" x 3/4" (1) plywood piece
for the substrate
- 20" x 7-1/4" x 3/4" (1) plywood piece
for the shelf
- 20" x 4-3/4" x 3/4" (2) plywood pieces
for the legs
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A Note About the Design
The holes are spaced 3-1/2" apart instead of 4-1/2"
to 5", which makes it easier to place the Wonder Dogs in
the correct position to clamp different types of glue joints.
The jig could be built without the shelf, which would allow
the top and the substrate to take the strain put on the bench
dogs and Wonder Dogs. However, the addition of the shelf means
that the holes in the top do not become oversized with use.
Without the shelf, each hole in the top and substrate is deformed
in two directions; it is pushed forward by the clamping pressure
and pushed backward by the torque. With the addition of the
shelf, the whole of the top and substrate resists the clamping
pressure; the torque is controlled by the shelf with its greater
mechanical advantage.
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