Centuri Argus #KB-9, Build, Part 4, Engine Mount Gussets

The outside diameter of the rings was a little small. I decided to add some balsa gussets for a better fit and a stronger mount.

Scrap balsa was cut to the width between the centering rings.
The glue fillets already in place didn't allow the balsa gusset to slide all the way to the engine mount tube. I sanded the corners off to fit over the fillets.

 A strip of copy paper was wrapped around the tube. After being cut to size, it was folded in thirds and marked. The mark locations were transferred to the engine mount tube.

The gusset pieces were cut wider than needed and glued to the 120 degree marks, with two centered around the engine hook.




The gusset sides were sanded to allow a slip fit into the ST-13 (BT-56) lower tube.
While the fit of the mount is much better, I still have build up the outside diameter of the centering rings with a bead of glue before gluing it into the tube. The gussets add a lot of strength to the mount.