The original 24-inch wingspan Dakota is
in the background. In front is the BMJR 12-
inch wingspan, 34.5-gram Dakota that is an
electric-powered FF model.
The author added a BSD E- 20 timer and
a single 150 mAh LiPo battery cell on the
underside of the 12-inch Dakota. Not seen in
this photo is the P- 51 brushed electric motor
that was used.
The key item in this photo is the word “outdoor.”
This red, double-sided mounting tape has a
stronger adhesive than the indoor variety.
Q636: I noted with interest he piece in your June 2016 “Frequently Asked Questions”
column about the new E- 20 electric-powered Free Flight (FF) model contests.
I’m not a contest-type person, but I
began wondering if the E- 20 power
system could be used on micro-size
sport or scale FF aircraft, just for the fun
of it. Do you have any thoughts?
A636: I hadn’t given that any thought
until this reader wrote to me. Since
publishing my little FF E- 20 Civy Boy,
I’ve logged many flights on it. They have
been basically short flights, because at
age 78, I’m not too keen about chasing
models across the field.
I’ve learned that the E- 20 power
system, consisting of an E-flite P- 51
brushed motor, a special timer
developed by Bob Selman of BSD Micro
RC, and a single 150 mAh LiPo battery
cell, is capable of flying models weighing
up to 2 ounces. E- 20 airplanes must
weigh at least 1 ounce. To win, you want
to be at that mark. Believe me—that
motor system has considerable power
Keeping all of this in mind, I decided
to install my E- 20 power system into a
12-inch wingspan Dakota biplane that
was built from a BMJR Models kit by
my friend, Jon McVay, who is from Iowa.
This was a gift for me in 2005. This little
biplane originally weighed 40. 5 grams,
including a two-cell 150 mAh NiMH
battery. The motor was also heavier than
the P- 51 motor.
After installing the E- 20 power
equipment, I got the weight down to a
mere 34. 5 grams (or 1. 2 ounces). What
a shock when I made my first flights.
The little airplane went like a rocket. I
reversed the propeller in order to reduce
the power. I generally set the timer for
approximately 8- to 10-second motor
I’ve been flying it at a local soccer
field and can keep it within the field
boundaries in calm weather conditions.
I can obtain approximately five sorties
on a single charge. I usually bring three
fully-charged batteries to the field, so
that gives me a chance for 15 flights.
If you are interested, Brian Malin,
from BMJR, still offers the little 12-
inch wingspan, laser-cut parts kit for
the Dakota. I’ve listed BMJR in the
“Sources” section, along with BSD Micro
RC, which can supply the P- 51 motor,
E- 20 timer, and special propeller. For
batteries, I like the single 170 mAh LiPo
cells from Josh Barker of MaxAmps.
com. MaxAmps.com is also listed in
As for other kits, try the Dumas
Products website and look up the
Walnut series. Dumas Products has a
“fleet” of 17-inch wingspan rubber-powered model kits that can easily be
converted to E- 20 power.
Attaching Servos With
Q637: I noticed that on all of your
published micro and park-flyer designs,
86 Model Aviation DECEMBER 2016 www.ModelAviation.com
FREQUENTLY ASKED QUESTIONS
Micro-size electric FF models