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How I put together a rim
Posted: Tue Aug 23, 2011 7:06 pm
by JRHall
I just started a Walnut L-00 build, and I thought I'd share my process for assembling the rim.
As you will see, I'm a firm believer in the liberal use of radius dishes.
We start with a set of sides that are trimmed precisely to fit the mold. John Halls YouTube videos cover this step very well so I won't show this.
Here is the first point I depart from "normal" procedures. Make sure the ends are perfectly square.
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:13 pm
by JRHall
You now have a pre-contoured back edge and a straight edge for the top with both end at exactly 90 deg. to the top edge.
Place the top edge of both sides on a flat surface and the ends should join cleanly. This is how I glue in the neck and end block.
First the end block:
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:19 pm
by JRHall
Now the neck block:
Make sure to check that the open end of the neck joint is towards the top. Don't ask why I think this step is important.
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:26 pm
by JRHall
Now the setup I use for truing up the radius.
Here's a view of my workbench top.
Notice there are three strategically located holes.
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:31 pm
by kencierp
Well you and I will both be picked up by the "
luthier police patrol" since I also show an article gluing in the blocks outside the mold -- which BTW is how most of the large scale builders do it.
http://www.kennethmichaelguitars.com/rim.html
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:32 pm
by JRHall
Here you will see, since the top edge is still straight, it lays flat on the workbench all the way around giving full support against all the pressure you want to use as you radius the back.
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:38 pm
by kencierp
Are the sides pre-profiled? Or are you doing the all the profiling with the dish?
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:40 pm
by kencierp
BTW that rim is bent as it should be -- it snaps right into the mold no need for a zillion spreaders -- NICE!
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:40 pm
by JRHall
Now here's where we flip the rim and do the back.
I have a 16 ft radius dish drilled to clear the dowels and pipe on the bench.
When I place the rim on this with the back side down, I still have full support around the whole rim. This lets me use only a waist spreader without worrying about the rim slipping in the mold.
Re: How I put together a rim
Posted: Tue Aug 23, 2011 7:42 pm
by JRHall
kencierp wrote:Are the sides pre-profiled? Or are you doing the all the profiling with the dish?
I pre-profile with a router pattern before I bend the sides. Then all I have to do is touch up.