Machining Convex Raised Panels

Woodworkers describe a curved shaper jig for machining the edges of a concave panel. July 11, 2007

I need to run some convex raised panels. I've done convex cabinet doors before, but only flush panel doors. I can visualize the process utilizing a vertical raised panel cutter and a fixture for the panel ends. What type of fixture do you use for the panel sides? If you have run these before I would appreciate any information or pictures of fixtures you used to run it.

Forum Responses
(Cabinetmaking Forum)
From contributor P:
There are many ways to do this. I assume you are using a shaper, not a router table. You can use either, but I feel the shaper is best. I have never bothered with vertical panel raisers, so I will discuss using traditional panel raisers.

You can do the ends this way by making a concave curved table that the panel you're machining slides through on an arc. The curved table clamps to your shaper table. The panel you are running is face down. To the ends first.

Next you need to make a simple fixture to hold the panel so the edge is at a zero tangent to your shaper table. A sled will work too with a couple of simple curved wedges to hold the panel up at the correct orientation. Sneak up on the cut depth as the panel profile will distort somewhat as it transitions from straight to curved. I use a tilt arbor shaper for this, so my curved table doubles as my sled to cut the edges.

To me, the rails are the trickiest part if you are doing cope and stick.

From contributor B:
I have done about the same as contributor P described. The groove in the rails will be a little wider than normal because of the arc they go through when cutting. Assuming a normal stick set, flat stock on a shaper. If you were to run the groove vertical, say on a router table, then it would be net the width of the bit.

From contributor T:
Martin Woodworking Machinery represents a line of accessories by Aigner Company. The brochure for these accessories has some good photographic examples of what contributor P is talking about.