The framigami idea paid off, and compared to #10, the frame for 622 went together very quickly. Of course, it didn’t go perfectly according to plan. There are a few things I will change if I re-draw the etching artwork, and a few things I would remember to do differently next time.
Things for next time:
- Remember to drill the holes for the fall plate while the frame is still flat.
- Anneal the firebox before embossing all the rivets, then sand off the oxidized layer before using it. Even after much polishing it was difficult to get solder to stick to the firebox, except of course where I didn’t want it.
- Very little solder should go on the springy beam pivot! I filled in this slot and had to create a specialized tool to scrape it out.
Things for the next design:
- The long fold lines were very challenging, and for the most part unnecessary. Next time, I will fully etch through much of the fold lines.
- The cutaway alignment jig beneath the firebox needs bigger cut-outs to enable me to get a soldering iron in against the firebox.
- The holes for the air lines are on the wrong side!
- The little tabs to hold the back of the firebox in place didn’t work worth a hoot. They should fold up from the floor where there is ample material.
- The transverse stiffeners on the ends of the assembly pan did not get used.
I’ve left the end tabs akimbo until the soldering is mostly over and I’m ready to epoxy them. These will have an insulating gap between them to split the frame in two.
Pembroke:87 
Good to know about the long fold lines and having them as a full etch. As you know, my model is quite long compared to yours, so knowing this about long fold lines (15-18″ long) will help me big time.
Craig
Oh yes, 18” would be very long indeed! If you can get away with it, etch fully through in a dashed line within the half-etched fold line. The outside corner won’t be as clean, but the fold will be easier.