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Banjo rim #2 - second layer, a change of tactic

I'm still experimenting with things really, and decided to try a different approach for the next segment layer. This time I thought I'd make a octagon using 45 degree scarf joints. There are a number of reasons why.

  1. I'd had difficulty with the mitred angles on the previous layer, and using scarf joints means half the number of angles to using equal angles each side of the block. Half the angles means the cumulative error is going to be less if anything is off (in theory).
  2. The wood I have is a not really as deep as I would like, and doing it this way means initially I only need to get one side and one face squared. The other face can be fixed after gluing the segments.
  3. I don't have to worry about the length or width of each segment providing they are above the minimum requirement.
On the downside, the glue-up is tricker as I found out later.

So here is how it works out in sketchup
11 inch segmented rim using 45 degree scarf joints
First off, I trued up the mitre saw using a digital angle gauge and adjusting the fence

bang on 135 degrees
Then I cut everything and clamped the pieces to a flat surface.

testing it all fits
When I came to put the final piece it it was a mile out


How in the hell did that happen?

Anyway, I pressed ahead and glued up part of it, and I will use the disc sander to get that final part true later.

One thing I'm a bit annoyed with myself about though is I cut the mitre joints at 135 degrees instead of 45 degrees. This doesn't really matter, but I was intending to use a jig and make layer roughly circular using the table saw, and because I'd need to turn it clockwise into the saw blade this would result in tarot because of the orientation of the grain going into the saw. So I will have to flatten to rough surface first, then flip it over before doing that.


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