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That makes a lot of sense to me Tim... very good advice. Thanks.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Would you mind shooting a picture of that for me? No hurry...

Thanks man.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Yeah my set-up is just about like Tim's, I believe my final speed is around a 100RPM and it never bogs down.

GG

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Gwaltney Guitars

Brock,
Here are a few pictures of the dish sander I built. This was originally inspired by Tim's design but I used a right angle gear drive system that he switched to later. I also add threaded rods to align my mold and set the depth per input from John How. I used a variable speed drive to convert my 3 phase motor to single phase but the control also allows me to have a on the soft start on the motor which is nice. One feature I have not added is a foot switch to turn the sander on. Tim added this to his sander and it was really great. Tim also added a nice dust collection system that is very effective.


3/4 HP Baldor Motor with a Boston Gear right angle gearbox. I mounted this on a separate base plate so I could drop the sub assembly into the sander cabinet.

Motor sub assembly mounted in the cabinet.

Top added to the sander.

The sander sub plate with 4 drive pin for driving the radius dish.

Room in the cabinet for radius dishes and dish routing templates.

4 threaded rods with wing nuts to adjust sanding depth. This allows the ability to sand the sides, add the linings, and then sand the linings to the same depth (thanks John How for the idea)

My radius sled assembly to make my own radius dishes. The templates are mounted to the sides of the cabinet. The sled slides forward and back to create the radius. The wood cross rods look rather thin but actually are fairly rigid.

Side view of the cabinet and radius guides.

I was able to find all major parts for the project at a local surplus machinery warehouse or Ebay. This helped keep the cost down while still using good quality components.

Best of luck with your design!

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Brad
Avon, OH

Brock,

Mine is indeed a 1/2 hp appliance motor and have made quite a few radius dishes with it. I have the top of the motor (mounted outside the back of the unit) covered and very little dust gets on/in it, even though I can fill the shop with dust when spinning dishes. I do think that Brad's (and now Tim's) are the Cadillac and would opt for that option if I was doing this again. But for the work I do this works great. But you do need to use the John How depth stops, it makes setting the sides to the correct depth and taper a mindless and efficient task, set the form on, turn on the power, crack a beer and it's done. Easier to watch that David's apprentice!

Shane

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Canada

Brock,
I have a 1 hp/1750 rpm motor sitting here in a box waiting for me to break down and
build the rim sanding unit. I'm going to include the full dust collection shroud right
away to avoid the clouds that they kick up.

Regards,
Kevin Gallagher/Omega Guitars

Kevin,

I have found, as others have already stated, that at 100 to 120 rpm sanding rims with linings, there really isn't much dust. It all stays on the disc and pools in the middle. When you are done, a quick hit with the shop vac and Bob's yer uncle! Now, if you plan to sand at 1750 rpm that is a different story and I will be standing by for a link to the You Tube Video

Shane

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Canada

I use 36 grit paper on my hand turned dish,then clean it up with 100 grit-makes short work of it.

On these right angle gears, do you need to match them with the HP of the motor? I see some that have HP ratings on them.

Also, what is the "overhung load" rating? That seems to be a big variable in the cost.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Holy smokes!!! That is nice.

You just took my project to a whole new level. Thanks!

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Wow.....
Hey Brad, can you give us a part number on that right angle gear box? How much $ do they go for?

Sweet unit. I totally forgot about that.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

You will not need to worry about the overhung load rating because there is no over hung load. In my case I mounted the adaptor plate directly to the gearbox so their is a thrust load from the radius dish but it is minimal. For those who use Lazy Susan bearings there is no thrust load. What is most important is that the gearbox size is matched to the motor HP size. It is also important to make sure that the mounting size of the motor frame matches the reducer (gearbox) size. If it is all matched correctly it is really simple to mount and should work. If I recall correctly I purchased the gearbox new on Ebay for $40 and it was in like new condition.

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Brad
Avon, OH

Don...I will check out the gearbox I have and let you know what it is.

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Brad
Avon, OH

The easiest way to put a gearbox together is to get a C-face motor with a C-face motor mount reducer. Typically the motor mount size for this application is a 56C. It is important to make sure the motor frame size matches the reducer size and that the motor shaft diameter matches the reducer input shaft size. This isn't very complex but if you are buying stuff of Ebay then you have to ask the seller a few questions to make sure you get everything right.

Here are a few pictures of a typical C-face motor and reducer input.



As for the reducer...most reducers should have a name plate. The nameplate data will give you the input RPM, input horsepower (HP), service factor, and ratio (along with some other data). Since most motors are 1750 RPM then if a 15:1 ratio is used then the output speed will be 116 RPM. This should get you close. If you use a 3450 RPM motor with a 1750 RPM gearbox then expect a mess...it probably will not work very long before you burn up the bearings and the gearbox fails.

If you get the correct ratio, correct input speed, and make sure that the reducer HP exceeds the motor HP then everything will work great and should last a long time.

Here is a sample reducer nameplate...


For this reducer the unit is rated for a 1750 RPM motor input, 2.01 input horsepower, 5:1 ratio, and service factor of 1. This is just a sample name plate. If this same gearbox had a 15:1 ratio the motor HP would drop to .625 HP which would be the max. motor size.

So back to your original questions...what model number? You just have to look for a model that has the correct motor frame size and nameplate data. From my experience these gearboxes can usually be found on Ebay for less than $50. Many of the gearboxes on Ebay don't show the nameplate data but typically the seller will provide the information if asked. I just takes a little effort.

If you have any questions just let me know and I will be glad to help. Since I spend my days working for a company that designs and builds very large gearboxes this is one of the rare cases where my professional career ties directly into my guitar building.

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Brad
Avon, OH

Cool. Thanks.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

David I really enjoyed that.It was a bit poetic.I`ve got some song lyrics I`m sure you could help me improve.
James

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James W Bolan
Nashville Tennessee

Check this out from Greg Nelson - pretty cool. http://luthiertube.com/mediadetails.php?key=72a086fad68cfe462764

Just when I think I understand tings, a subject like this comes along. What is a rim sander? (yes, I can see the pics). But I thought the shape of the rims was determined in the initial part cutting.

To be frank, I do not even know what a radius dish is used for.

Yes, I am ignorant... but my first guitar was a kit... next wil be scratch.

Mike

Mike buddy perhaps you have read here about how many of us build our tops and back with a radius to them?

Radius dishes are a bowel shaped dish with a specific radius. You can purchase these or dust up your life and make one.

The braces for the tops and backs are sanded to the desired radius in the dishes. Tops and backs have their braces glued to them while also in the dishes.

The dishes are covered with sand paper, I like 80 grit, and the entire rim of the guitar is sanded in the dishes so that the tops and backs that are already built to a specific radius fit nicely. Of course the back of the rim would be sanded in the respective radius dish that you use to build the back. I use 15' but there is no rule here. And the top of the rim is sanded to the respective radius that the top is built to - I use 25' and again there is no rule here.

I am not at my regular computer right now so I don't have access to see if I have an pics of a rim being sanded in the dish.

I hope this helps.

Mike here is a pic that I found of an L-OO rim being sanded in a radius dish. It's also a very rare shot of dust in my shop.....

Some folks sand the rim with the rim on top of the dish and others will place the dish, face down, on the rim. The folks who sand with the dish on top of the rim are known to call the back and forth turning of the inverted dish "driving the bus..."

When the rim is on top of the dish the entire mold is rotated back and forth until the blocks and sides have no gap. It's easier to do this prior to installing the kerfed linings and then touch it up in the dish after installing the kerfed linings.