jim:
Thanks for the response, and the comments. I’ll include a picture of an early, rough version of the Transition Block. I am unhappy with the quality of the arc’d mortises – I started-off doing these with a Festool Domino (with initially good results); however, a 2" depth was necessary – which is well-beyond what the Domino can provide. A follow-up piece would require a precisely-made template for heavy-duty routing.
The Crest Rail was made by creating two 1″ × 4″ × 30″ strips with mirror dados cut on the table saw. When glued-up, it is then cut into 8 sections; 4 degree mitered edges are applied, then glued – thus creating the arc. The Crest Rail’s arc radius is the same as the Transition Block’s radius: the Back Braces naturally extend through the Crest Rail mortises.
You Take Care.