The last step before applying a finish to everything was completing the bell.  As I mentioned at the end of Chapter 2 about making the bell on my CNC, I had removed the recess for the external sleeve from the components  when machining the parts for the bell.  This turned out to be quite a pain to deal with.  My original plan was to try to cut and shape the recess by hand but that was going to take forever and challenges during the glue up made that even worse.  Instead I decided to use my router table with a profile bit to remove most of the wood.  This was risky but I figured  that this is an experiment after all and if I destroyed the bell, I would make some design tweaks and remake the bell to eliminate this step. 

This required that I insert a guide into the end for the bearing to follow.  Because after glue up challenges the end turned out to not be round, this meant that I had to make a a template that basically converted the oval shape on the inside to a round one on the outside that matched the shape and size of the recess of the joining straight section.  Here is the insert that I made and the setup on my router table.  The insert fit tightly into the end of the bell and I clamped a scrap of  MDF  to the table  so that the guide could rest against it and the bearing at the same time for stability. 

This was a scary process as I had to balance the tall curved bell on top of the router table while slowly turning it.  I did it in two passes and left some extra material to sneak up on a final fit.   I did not get any pictures of the process but here it is after the first pass.

The second pass was done with the template resting on the table.  The template sort of acted as maximum as I did wanted to  leave room to sneak up on a fit.  This is partly because with the curve, the wall is going to be very thin on the top side of the bell.  I figured I can compensate a little by adjusting the internal size of the outside ring.  Here it is after the second pass as I start final shaping by hand.

To join the bell to the first straight segment, I used the same external and internal sleeve approach I used for the joining the straight segments.  With the curve coming right up to the joint this proved to be  a problem because the internal sleeve ran into the side, preventing it from going in straight.  I compensated by cutting out a portion of the tube.  I didn't take a picture of it before I glued it into the bell but here is it is cropped out of another photo  (and slightly distorted) .

And glued into the end of the bell.  I used epoxy because of the way it fits and because it may see a lot of stress. 

Because there is a lot of space around this sleeve, I decided to pack the gap with Milliput epoxy putty.  It is ugly but this should significantly strengthen the joint.

The external ring was glued on with epoxy and I made a foot that was also glued on with epoxy.  There is a dowel in the foot that only goes about 1/8th inch into the bell but is is mostly there to help hold it in place while the epoxy cures. 

If I were to ever make another of these, I would modify the bell design to extend the bell to include 2 or 3 inches of the straight section (subtracting from the first straight segment).  This would make this joint basically the same as the other straight segment joints and greatly simplify the construction and strength of this joint.    As it is I got a really tight fit on this joint adn I am going to recommend to my fried for whom I made this that he just leave the first segment and the bell joined to gether. 

The last step before final finishing was to add a ring on the end of the bell.  I designed and carved a ring on my CNC.  The purpose of the ring is to help prevent the glue joints of the individual segments that make up the bell from separating with exposure to environmental changes.   Again the bell is slightly oval and I made the ring oval as well.  It was still slightly too wide so I cut it in half so that the saw kerf made it slightly narrower and glued it back together.  It too was glued on with epoxy. 

The final step was to apply a polyurethane finish inside and out, wax and grease up the joints and call it done.  I may turn a few more mouthpieces to experiment with different sizes.  I may also make a little tripod stand to rest it on when assembled but not in use.  Now I have just have to learn to play Smoke on the Water.