Dayton Free Flight  is based on the Squirrel and looks a lot like a Squirrel but different design constraints were used. The requirement for the model to be entirely stick and tissue was dropped. The Squirrel balsa processing (stripping and chopping only) was dropped. This opens the door to interlocking parts and new tools such as laser cutters. More emphasis was put on cost as well.

The Dayton Free Flight is aerodynamically different than the Squirrel.

• The wing is 0 degrees,
• tailplane has negative incidence ( 3.6 degrees, 3/16″ over 3″, wing/tailplane measured from fuse center-line) and
• the airfoil is different (tissue on top).

Dayton will also have control surfaces! A rudder, elevator and ailerons!

It also has rounded stabilizers so they don’t hook up on branches as much. Might be safer too. The stabilizers are 20lb bond so they can be pre-decorated (or even laser printed). Stabilizers have either no spars or incomplete spars to increase flexibility as well.

There are big differences in construction. The wing is built bottom up. Here is the procedure so far:

1) Lay out tissue and glue stick leading edge.
2) Place 2″ spacers at wing rib positions. Glue trailing edge. Remove wing rib spacers.
3) Glue the notched wing tip ribs. They go vertical on top of the leading and trailing edges.
4) Add shards to wing center. Cap wing root with 4″ balsa strip (not shown below) to form wing handle.

The tail planes are different too:

5) Cut fin, tailplane and winglets out of 20lb bond paper. Mine had a flower on it I painted a while back. Also, cut  rudder and elevators.
6) Glue fin and fin spar.
7) Glue tailplane spar and tailplane.

8) Rear motor hanger is glued and capped in place (this step will be moved to an earlier position so the glue will have more time to dry).
9) Glue winglets.
10) Tape wing on using 3m tape. Use two loops. One at the front and one at the back.

Install propeller and elastic motor and we’re ready to go!

Flying

I did a couple of flights. It zoomed a bit on the launch and showed a phugoid behavior as the power came off.  Very nice flight. I added a bit of down elevator and tried again. I’m quite pleased.

Next Steps

I felt that 3.5 degree negative tailplane was a bit much but for some reason I wanted to try it that way first so it would be  floaty. I will make up some different tail booms with different angles and will see how it behaves.

I am adding a full length tapered aileron to each wing. This will make the Dayton “full house” in terms of control surfaces. It will also increase the wing area and match the rounded stabilizers.

I feel these construction methods are ready for some testing so I will make up some Daytons with different tailplane angles. I’m not settled on the 20lb bond. Brett Herrick has had some luck using it for the whole airplane. So I am giving it a try for stabilizers (eliminating the winglet spars and reducing the tailplane support to reduce weight gain). After the first run, I’d say this looks promising.