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Using a standard dish to profile the back is a pita. You can either sand in rotation to get a 4-5” sanding stroke, or go back and forth which leaves half the frame hanging in midair and wastes half the effort.

What if you had a giant radius dish?

That’s what this is, the inside 22” of a 42” radius dish. The back side is flat for doing the top of the rims.

This is going to save a lot of time.

Was it cheap? No.

Is it heavy? Heck yeah.

Is it awesome? I think so…

Custom milled for me by Josh at House Guitars…







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That oughta save some time.

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Steve Smith
"Music is what feelings sound like"

That’s my hope!

I've been using John Hall's method of driving the bus with a hole in the middle of the dish with an axle going through it and a handle on the back where you get full rotation of the sanding dish. It goes very quickly, and I find moving the dish instead of the rim to be much easier. Lots of ways to skin that cat.

Dave

Yup...

Cool! No matter how hard I try to play it cool I always bust into a flop sweat driving the bus.

Dave. I like that axle idea too! Put a suicide knob on there and let it rip!

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I made a portable version using a Bosch mixer. It has removable dishes and 3 speeds. I also made one using a bowling ball balancer. That one is very aggressive and can remove 1/2 inch of side material in about 5 minutes.

Here is a cheap way to do it using the drill press for power. It is perfect for small instruments, like ukes, but I also do my guitars on it. The only real issue with guitars is the height of the drill press table. Working with the heavy guitar molds at chest height is not for small people! It does , however remove material fast and easy. http://www.pegasusguitars.com/making-a- ... s-jig.html .I still hope to make the real deal someday.

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

This is an ‘in the meantime’ solution, but if it works as well as I hope, it’ll probably just be the solution, lol.

The powered dish sander I built is definitely not the general utility player that my bandsaw is, but I appreciate having it when I need to profile a set of sides. I hate driving the bus!

That new dish design looks like a huge time saver and it’s storable. Josh does make the best dishes out there. Not cheap but worth the price!

M

I really like your design Michael, and may get around to making one myself one day, but this will serve some time in the interim...

So are you pushing the mold assembly in the direction of the long length of the sanding jig to produce an arch? Or set it in the middle and go across the short way? I'm trying to understand this... Or is it a bit of both?

The long length...it's the inside 22" of a 42" dish...

So you are arching the length of the back with the dish, and arching the back braces to provide arching across the back, and using a flat rim on the soundboard?

It's just as if I was using a normal radius dish, but it's bigger. So it has a 15' spherical radius, just like a normal radius dish. Yes I sand the top of the rims flat. I use a 28' radius for the top braces including the UTB. When clamped to the flat rims it builds in the correct geometry for a bit of fallaway, which I like to have.

You know what would be cool? A flip top workbench with this workboard on one face and something very flat (MDF) on the other face. You probably wouldn't want to use the workboard as the bench top alone, just because it might sag. But mounting it on a rigid flip top could be really nice. Just an idea.

Yes!

Here are a couple pictures of the bowling ball balancer sanding dish. There is a belt under the base that runs from the motor to the BB holder that supports the dish.
The dish is a piece of plywood with wedges glued around the perimeter, a piece of thin meranti plywood glued to the wedges and screwed down in the middle. It's a less dusty way to make a dish. It's probably more of a spline curve rather than a true radius, but it seems to work fine. When I do a "reboot" on it I will switch out the wedges for a continuous circle of thin plywood to form the raised edge and use larger pieces of sandpaper to have fewer "joints". I have used this dish for a fair number of years, and even with the missing sections of sandpaper it still works. I like the portability of it and it's relative compactness, but the Bosch is slightly better in this regard ( the dish is easily removable on the Bosch).

There's no doubt that motorized is the way to go, if you're smart enough to make it happen!