Feb 9, 2011

Blu-Cub Full Fuse

After my first successful build of the profile Blu-Cub, I figured that more traditional building techniques could work well with foam.  The Blu-Cub provided me with a starting area for this project, but the result looks a little different than the original plane.

Starting with the two fuselage sides, I trimmed the foam at the tail end of the plane and glued pieces together with hot glue.  From that point I added a bulkhead about 1/3 of the distance from the tail to the nose, then I cut pieces to fit the top and bottom areas between the tail and bulkhead. And then worked my way forward from that point cutting pieces to fit as I went.

For the motor mount, I hot glued the threads of the lid of wide-mouth bottle, to the foam firewall.  The motor is attached to the bottle lid, and then the lid is threaded onto the bottle.  I did this to allow simple motor swap outs, if I'm under powered, I just get out another motor and bottle lid, and swap them out just like that :)  For access to the wiring, and for the battery, I put a magnetic hatch on the nose.

I decided to make the wing a band on wing, so I made the wing with an under-camber which matched the curve in the top of the fuse.  Adding the additional foam to make the full fuselage increased the weight, so I decided to slightly increase the wing length to reduce wing loading.   I reinforced the underside of the wing with the thinest carbon fiber rod I had which would provide adequate stiffening.  On the leading and trailing edge of the wing I hot-glued on a very tiny piece of carbon fiber rod to keep the rubber bands from working there way into the foam.  This was then covered with yellow duct tape.

Landing gears are proving challenging, I need a wire bending tool.  I hand bent my gear with pliers and a vice, I don't recommend it...  The piano wire I'm using is a little thin, so I added a cross member so they won't splay on landings.   

I'm finding that foam is a fairly simple medium to work with, and with a bit of care the results are very decent.

The plane is now awaiting electronics installation and flight testing.  


  1. It looks like a fairly wide wingspan for this beauty. I have been free flying a Piper Cub paper model airplane with some success, but it is somewhat small with an 11" wingspan.

  2. @JetAviator7 Looks like a very intricate paper airplane! I might have to give that a try:) The wingspan on this plane is around 28" When I get the electronics in it, I'll post all the specs and gear used.