I did not use the hardware and hinges from kit. I used good quality Dubro and GP hardware and hinges. I also used two servos for the elevator rather than connecting the two elevator pushrods. I shortened the engine box by 1/2" so the engine would fit the cowl. The information on the cowl diameter does not let one know about an indentation in the cowl that reduces the diameter to about 7". This made mounting the cowl a real challenge but it was accomplishes by cutting windows in the cowl for the Kelco exhaust ring and the two lower cylinders. I am using LiFe 2500 MA batteries for the control system and the ignition. I also installed a 32 oz fuel tank with a fuel dot for filling. Here are a few pictures of the D21 under construction.



Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)