MIMF

Hello Everyone,

I believe I posted this sometime back but thought it may help those just starting out so here is how I make a radius dish. It is a fairly simple, albeit dusty, procedure. I use two 3/4" MDF boards that have been glued together this way you can put a different radius on each side if you choose to. After selecting the size needed (in this case 16") I drilled a centered hole for a dowel which allows me to 'spin' the dish while cutting. I use three MDF slats as the base. The center one has the dowel pin.

The router jig is a simple open box with rails that have the coordinating radius and is sized to fit the router base so it slides along the rails. I set it so that there is about 1/16" of room between the bottom of it and the dish. I use a 3/4" router bit and hold the router stationary while turning the blank. Once around I simply slide the router down a bit and continue until I reach the center. I then lower the bit a smidge and work my way back up the hill. This really cleans things up and then requires very minimal sanding to smooth things out.

This dish is for the tenor Ukulele. The circular portion of the dish is 16" across and the radius is a little over 4-1/2 feet. This gives me a Ukulele back that is 9" wide at the lower bout with a 3/16" arch across. Of course there is also arching occurring from top to bottom as well. The joy of all of this is that you can create any radius that you'd like.

Happy Building!
DJ

DJ, if you mount the dish blank on a lazy susan bearing, your router bit will spin the dish for you as it cuts. Takes about 2 minutes to make a dish.

Bob

I've got one with a lazy Susan, but it won't spin itself.

I made up a dust collector for it that worked out well. It's a short length of PVC pipe glued to a thin disk of particle board that is screwed to the router base, with a port for the narrow tip of the shop vac. I put a gasket of foam around the opening. It sheds almost no dust. I needed a dish one time when the weather outside was awful...