40" Swappable Specter - an IBCrazy design

After building the last specter and getting quite a few requests for more information on how I did a few things, I decided to build a smaller version for my father.  I used a few different techniques that are outlined.

Everything he flies is swappable.  I did a 3/4 scale down so that we could get the weight down on if for smaller motor/esc combo.  The wing span measures 40" and the tale is a perfectly scaled 3/4 from the my original design (minus the rudders, I made them a little larger for good vertical stabilization).

This should be quite a bit lighter than the previous.  The wing is much stiffer and the fuse is permanently attached to the wing, and accepts the swappable fuse (in pusher mode).  The fuse inside dimensions is exactly 2x2".

As you can see we are about 8" shorter than the first edition.  We still haven't gotten this 100%, but the purpose of this was to show the construction of the forward sweep.

So here it goes...

I put the wing on a flat square surface.  Measuring 1.25" back (1.75" on the 48') from the front edge of the wing at the root, I marked the bottom of the wing and cut the excess off.  Note: for the wing spar, I used a 3/4" foam spar, one sheet thick all the way through and 2 sheets thick on the root side 8" long.  This made a much better taper than on the previous wing.  The connecting spar was 2 sheets thick, 10" long and glued on the front edge of the wing.

This is what you should be left with.  I did the same thing on the other side of the wing to keep the wing tip parallel.

A closer look at the measurements.

For a closer look at the fuse for the swappable, I've added the pictures below.  The fuse is built to snugly accept the swappable fuse, being that it is a swappable, we probably wont even be adding the BBQ skewers or tabs. It was a super snug fit.

Back of fuse.

The tail measures as follows:  Elevator - 11x3 3/4" , Vertical Stabs - 6x3 3/4"

The tail sections were spliced together with a 1.5" overlap on bother sides.

We used 2 carbon rods for the tail (my dad had some broken fishing poles lying around).

The nose was brought together and kicked up a little on the bottom (mostly for looks).

The tail spars continue through the center of the wing through both wing spars, and continue clear to the back of the tail.  The distance between the tail and the wing at the spar is 6". Total length of the spars were 14", and the distance between the spars are 9 1/4".  The fuse extends 8 1/2" from the leading edge of the wing making the fuse a total length of about 15 1/2".

All in all, we used 2 sheets of foam for this build (closer to 1 1/2), 2 carbon shafts from some old fishing poles, hot glue and extreme packing tape.  Stay tuned for a build video on this one.  I will be doing a fast-forward style video on this to show how it is constructed and what steps I took.

A big thanks goes out to IBCrazy and Experimental Airlines for the plane design and the Arman Wing design. Without all their expertise and experimenting, I would have this design to play with.

Also a big thanks to Flitetest!  These swappable series have opened doors to friends an family members to the hobby.  It's truly and inspired idea.

Click here for dimension on the 40" version.