MIMF

Gary Granger won the auction for one of my block rims for banjos. He chose an open back rim with a body of maple and a tone ring layer and bottom cap of cocobolo. A classic! I've made dozens just like this one. So, I thought I would blog the process for making the rim.
Production rim makers generally use one of two methods for making rims - laminating thin strips of wood in a circular mold or gluing blocks of wood together and the cutting it round on a lathe. I chose to do block rims right from the beginning and I've stuck with it.

So, here's the start of Gary's rim. I used a table saw and a crosscut sled set at 11 1/4 deg. to cut 1 1/2 in. wide strips of 3/4 in. wood.


Using a technique borrowed from wood turners who make segmented bowls and vases. I laid down a strip of painters tape - sticky side up - and stuck 16 blocks end to end on the tape.


After brushing Titebond on all the joint surfaces, I rolled the tape up to make a ring.

And then used a large hose clamp to squeeze all the joints tight. Don't worry about the slight unevenness on the top surface. I'll run all the ring/layers thru my planer before I glue them together.


Here are five rings waiting for the glue to dry.

Man I gotta get me some of them large hose clamps. Do you have a source? I've about decided on a 12-inch block rim for my next couple of builds.

I've used big rubber bands in the past. I like the hose clamps. No more shooting blocks. I'm going to get some of those big clamps.

Neat idea. you can all ways join smaller clamps together to make as big a clamp as you want.
Steven

Steven Wilson wrote:Neat idea. you can all ways join smaller clamps together to make as big a clamp as you want.
Steven

That's exactly what I had to do for my first ones for 11 in. rims.


Later I made some from one hose clamp, some pop rivets, and some plastic pipe strapping. This ones for an 8 in. rim. Also made some for 12 and 13 in. rims.

I took a couple of days off because of a cold - sniffling, coughing and aching. No fun, so I decided to try and cure it by dropping a lawn on myself. Strangely, that didn't work. Just added some new scrapes and bruises that hurt when I cough. What the hell! Suffering is the beginning of art! Onward and upward!

Back to work. Gluing a thin layer of cocobolo that will be the rim cap to one of the maple layers. I don't know why it should be called a cap when it's on the bottom of the rim.

I've got a few other photos showing the coco tone ring layer being glued to a lathe face plate and another showing two maple layers bonding. The photos all look pretty much alike, so to save band width, I won't post them.
Tonight, I should be gluing all the hunks together into a rim blank that could go on my lathe on Monday. Then the real fun begins.

All the layers in one lump on the lathe and ready to be cut.

The rim blank is glued to a circle of melamine that is screwed to a metal face plate. I always put a layer of paper grocery bag between the rim and the melamine. That allows the rim to be split away easier, but holds firm enough for the cutting and sanding.

You can get glue to stick to Melamine? Amazing.

I can't wait to see the cutters you mount in that jig on the cross-slide.

Jon Whitney wrote:You can get glue to stick to Melamine? Amazing.

I can't wait to see the cutters you mount in that jig on the cross-slide.

Jon
After a lot of experimenting with grinding my own cutters and buying ready mades, I settled on these from Grizzly with cabide inserts.
http://www.grizzly.com/products/Mini-Tu ... erts/H7535

Turning is done! Cut to 5/8 in. thick and about 3 in. high. Sanded to 320 grit.



Gary wants it drilled for shoe bolts, but not finished. I'll drill it tomorrow.

That looks Great!

You can get glue to stick to Melamine? Amazing.

Can you tell us a little more about that? I'm amazed as well.
Steven

Getting glue to stick to melamine? It's all in the way you hold your ears.

Titebond Original on melamine doesn't hold very well, but well enough for a temporary connection for turning rims. The glue doesn't soak into the melamine. After it dries, it's moderately easy to scrape it off with a wood chisel

I glue a layer of paper grocery bag between the melamine face plate and the rim blank. After I cut the first three surfaces, I drive a knife blade into the paper layer to split the rim off. It takes some effort to hammer the blade half way around the circle before the rim splits off the face plate. The paper usually splits right thru the middle, half still stuck to the rim and half stuck to the melamine. That's how good the dried glue connection is. I can scrape the melamine face plate down to a clean surface so I can use it again.

OK, it's done and already in Priority Mail to Gary.
Happy banjo building, Gary.

Nice work!