Can’t get enough of radius dishes, can we…

[mike243]

Kevin,

Two sided radius dish sounds great. Are there any times you wish you had two dishes; one for front and one for back radii? Or would that onkly be needed if you would be working more than one build at a time?

Thanks,

[mike243]

Sorry, I tried to delete the double post, but for the life of me, the directions for deleting didn't work, so this is an edit to the second post.

I've had the same issue twice in two days. When I hit "Submit" after typing my post, I get an error message, so I try again and get the duplicate. Then I go back in and find there was no error, and the first post took...and the second. Trial and error, I guess.

[Kevin Sjostrand]

Mike
My radius dish has a 15' on one side and a 28' on the other. I glued 2 pieces of 1 inch MDF together then routed the radiuses with the jig I made. Totally stable. Been using them for obout 12 years. Take 24" paper

[mike243]

Thanks Kevin. Seems like a good way to go.

[Kevin Sjostrand]

Correction
I have 15 and 30 ft radius dishes....

Here is my jig. Pretty simple. It straddles the disk to be routed and centered. There are removable rails I made for the 2 radiuses. So I put a shallow hole dead center in the plate that will be dished and put a pin in the bench, and now the plate can be rotated on center. Lay your router on the rail, rout up the rail and back, then rotate for the next pass. I used a 1/2" bit so you don't rotate it more than that. I only routed from the edge to the center.
Takes some time and makes lots of dust but it works. After all routing is down then I used a RO sander with probably 120 grit just to smooth out the surface. Makes a 24" dish, plenty big enough to do your Dreadnaught or jumbo guitar rims. I also clamp tops and backs to the rims in the mold in my gobar deck to glue them on.

Hope the pics helps someone build one for themselves.

[mike243]

Kevin,

Thanks for the photos. If I understand correctly:
1) The rails are swapped out depending on the radius to be routed.
2) The rails are indexed to the frame so that each set is in the same position relative to the dish center point, and the router bit begins cutting at the edge of the dish and travels to the dish center point (or maybe a smidge further). Then the router is either moved back to the edge along the rails, or is picked up.
3) Then the dish is rotated just slightly less than the width of the cut so there is some overlap with the last cut.
4) The jig is up in the bottom photo. Since the router path only goes to the center point of the dish, and not up the other side, the rectangular piece of plywood is to keep the sides of the frame parallel and past the center so it doesn't interfere with the router.
5) The jig rails are located with the dish center point halfway between them at the low point of cutter travel. The outer end of the jig is rotated until the rails straddle a radius line of the dish circle.
6) The jig is held in that position and the dish is rotated after each path of the router as stated.

That's what I deduced from the photos, so I think they do the trick for anyone to build themselves a similar setup.

[Kevin Sjostrand]

Mike I believe you described the process correctly. It was quite a few years ago when I made it and used it but that's pretty much what I did.
The rails swap out. You of course can make what ever radius you want.

[Stray Feathers]

When I made mine, I used a slightly different approach. I put a 1/4" hole in the centre of the dish so I could spin it on the base, and turned the dish through 360º at each router setting, starting at the outside, then moved the router on the sled just less than the width of the cut for another circular pass. Same outcome, not sure if one is better than the other, but another strategy in your kit. Bruce W.

[mike243]

Both ways would work equally well I would think. Interesting that you guys had different ideas of achieving the same end.

I re-watched the Susie Gardener YouTube video on her dish routing jig. Much more complex, with a trolley for the router that travels on bearings for wheels. Nicely designed, and we'll suited for a small production operation making more than a few dishes of various radii. But this design is simple, low cost, and seems like it would produce quality dishes.

[Kevin Sjostrand]

My dish did spin on center. Rotated for each cut. The sled remains stationary