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Archive for February, 2014
Posted by springer | Feb 13, 2014 @ 08:42 PM | 47,711 Views
I first saw this plane as a stick and tissue model plan in Model Aviation. Looked cute and I liked the bent wing shape, thought it would be a nice challenge to build that wing. Of course have to try and fit it onto a single sheet of foam (MPF this time). I built the model in Sketchup, and having the templates, got them laser cut. Man, it is really nice to be working with straight lines and smooth curves I didn't have to painfully create! Build went well, and I got her all ready to fly (made the mistake of paint first, my bad!) and had a fairly good first flight, but all subsequent ones resulted in some catastrophic failure, usually associated with tip stall or loss of orientation and subsequent spiral into ground. Very frustrating! Broke fuse in half several times, finally trashed the entire nose. Many tweaks, including changing thrust angle reducing wing incidence, adding more washout by heating and warping the wing (that was fun!). But the one single thing that made this gal work was increasing size of the horizontal tail! The original tail empennage was right off the threeview and just too small to maintain control. I added an inch to chord and 2 inches to span. Bam! now she flys just as predictable as one could ask, and I think the tail looks more "right" than when to scale. Oh, yeah, I swapped out the 40gram 1200kv motor for a 60 gram 1050 motor which really helps keep the speed up on landing.

The only thing I am still working out is getting a paint...Continue Reading
Posted by springer | Feb 13, 2014 @ 08:18 PM | 47,609 Views
Started a thread on this one in the Scratchbuilt foamies forum, but figured it should take a place here on the blog as well. Several years ago, I downloaded the "plans" for the Mystery Tailless Bipe. they were two letter size sheets of a stick and tissue freeflight version of this somewhat wierd looking plane. Always wanted to make an rc version. Well, this cold snowy winter had got me thinking of indoor planes that will fly inside a gym, so I threw together a twenty two inch span version. Fascinating plane, I set it up with elevons, and balanced CG at 25% of the total wing area aft of Lead wing LE. The thing flys really well. Here's the thread: https://www.rcgroups.com/forums/show...hlight=mysteri

I can motor around the gym nicely, although it's not as maneuverable as all the nutballs that surround it, but fun anyway. The 5gm motor isn't exactly a powerhouse, but it gets it flying ok for a 5 minute flight.

Here's the vimeo vid:
Mystery Tailless Bipe recreated in 22" span Model Plane Foam (1 min 33 sec)