A couple of years ago I attempted to clone the Acro-Bat. I found an unopened kit on the Air and Space Museum site (could only see a little of the instructions and a few parts), combined some X-21 plans and patterns from YORP. I wasn't quite sure about the canard release mechanism, but after seeing Tim's post..looks like l got it right.
The ejection charge moves the canard tube forward just enough to release the flaps. Another interesting find was the forward bulkhead was drilled with a small hole (I think perhaps to control ejection gas pressure on canard piston). Anyway after a little trim weight on the rear wing, it turns in some great flights.
The other rocket is my version of the Hans glider, based on the same principle.

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