The challenge: build a functioning ornithopter using stock and DLC parts.     This is a different kind of challenge. It is more like a collective "put our heads together" and see if this is possible.  I've spent a heap of hours over the past day and a half playing around with this with very limited results.     Here are the challenges and barriers I have discovered so far: 1.  Despite being able to flap like a hummingbird in the SPH, as soon as you pu