Wednesday, August 24, 2016

Foam ekrano-glider progress

Progress on the foam Chesapeake Sea Monster was delayed by a long weekend getaway (which also caused me to miss both August launches). I still hadn't figured out the entire motor mount/flipping canard design. So, I just started cutting wood anyway.

Here is a photo of the mount dry fit in the deployed position.  It will be pulled up by elastic bands attached to either the side wings or the rear wing. Both should keep the elastic away from the exhaust plumes.  The part I have not figured out is how to keep it in place during boost. One way is to have the motors hang out the front with a bracket to hold them down. But, will a motor eject itself if it is merely touching a flat plate? Maybe I need to have the motors' rear overhang mate with a bracket?

I also can't decide on the motor configuration. I'm torn between eight 18mm and two 24mm. Since I'm running low on Q2G2's, I think I want to reduce the number.

Finally, I wanted to limit the weight of the motor mount parts so I went with a slab of squishy balsa. I'm not worried about the boost but an unsure what will happen if the canard deploys at high speed.

One the original Chesapeake Sea Monster, I was worried about stability. Now I'm worried about everything else.