The jigs shown below are from the article "Get the Most from Your Planer" from issue 173, November 2006, of WOOD magazine.
Build the jig shown right, from 3/4" plywood or hardwood. (We used poplar on a Baltic birch base.) This jig will fit most planers, but you can measure your planer and adjust the dimensions as necessary. Cut out the two long vertical supports by first taping them together with double-face tape, then cutting and sanding the curves. Attach the supports to each other and to the base with #8 x 1-1/4" brass flat-head wood screws.
Build the two parts to the jig shown below—which are mirror images of each other—from 3/4" Baltic birch plywood or hardwood. Fix the two curved vertical support parts together with double-faced tape, then cut the curve on the bandsaw and sand smooth. Attach the supports to each other and to the base with #8x1-1/4" brass wood screws. Just be sure when assembling them to make them mirror images.
If you like this project, please check out more than 1,000 shop-proven paper and downloadable woodworking project plans in the WOOD Store.