Joshua Finn set new AMA records with his F1D and 35cm models. Finn photo.
Stripped Tan Super
Sport rubber is now
New rules and
by Don Slusarczyk
With the new rules for Fédération Aéronautique Internationale-class Indoor model aircraft (F1D) and the
adoption of Indoor micro aircraft (F1R) as an
AMA event, it did not take long for the first
records to be set in 2015.
The Thermal Thumbers of Metro Atlanta
held Indoor Record Trials on January 3 and
two AMA records were set. Joshua Finn set the
Category I Open AMA F1D record with a flight of 19: 22. He also set a Category I
Open F1R record with a matching flight time of 19: 22.
Congratulations to Josh on his record performances and a good start for the 2015
With Peck Polymers out of business, some modelers may have difficulty finding
stripped Tan Super Sport rubber in Indoor Free Flight sizes. Fortunately, stripped
rubber is again available in 20-foot lengths.
Sizes varying from .020-inch wide up to .160-inch wide in .005-inch width
increments can be purchased from DonsRC.com under the “Free Flight Supplies”
section. Each 20-foot section comes marked with the nominal size, as well as the
batch of rubber from which it came.
I have been making my own Teflon washers with sheet Teflon and a hole punch for
some time. The necessary supplies can be purchased online from McMaster-Carr and
will yield enough material for a lifetime of Teflon washers.
The PTFE Teflon sheet I use is part number 8569K18, which is .010-inch thick,
6 inches wide, and 12 inches long. The current cost is only $6.79. The company also
sells it in .005-inch,
.015-inch, and .020-
so you can buy
whatever suits your
I use a simple
punch to cut the
washers. A 1/16-inch
diameter punch is
the one I use most
often and it can also be purchased
from McMaster-Carr. It is part number
3424A57. The company sells larger sizes
such as 5/64 inch, 3/32 inch, and 1/8 inch if
needed for aircraft such as Pennyplanes
or Indoor Scale models. The punches are
priced in the $6 to $7 range, depending
on the size.
Cutting out the washers is simple.
Place the punch on top of the Teflon
sheet then hit the top of the punch with
a small hammer. Put a soft board such as
a pine board beneath the Teflon so the
punch goes easily through the material.
I cut out between 30 and 40 at a time,
because it only takes a few seconds to
cut one. As you cut them out, they will
group into the recess of the hole punch.
I use the back side of a drill or a piece of
music wire to push them out.
The last thing to do is punch a center
hole for the propeller shaft. Most of the
washers I use are for propeller shafts
with wire in the .008- to .013-inch
range, so my method for piercing the
center hole is simple. I use the tip of a
dissecting or insect-mounting pin. Both
have a longer, thinner taper on the tip to
pierce the washer. This is usually enough
to allow me to start the washer onto the
An alternative method is to use a
drill in a pin vice to make the hole. For
models such as a Pennyplane, where
thicker propeller shaft wire is used, I
pierce the center hole first, then enlarge
the hole with a drill bit in a pin vise.
134 Model Aviation APRIL 2015 www.ModelAviation.com