[bjesson]

Two thoughts:

Have your existing assembly tig welded. Might not warp too bad.

Make new parts that key together and provide the same rigidity. Might even bond them together with epoxy.

I'm thinking parts 16 and spacers machined from 3/4" plate with a tenon machined in the end of the spacer part. Pocket the #22 and #23 to receive the new tenon.

In my world, I would want to experiment with a carbon epoxy pay-up. But thats down the road a way.

I had similar thoughts as well. One other thought was pinning the spacers at an offset to the center hole, same concept as a tenon and keying the parts. This is all after thought stuff since it is already built but for people not at this phase these posts are worth their weight in gold. Unfortunately I didn't join this forum until after I was completed and Bob had mentioned it That should be another selling point for the plans, the designer is at hand! Maybe someday our paths will cross and I can buy him a beer

billj