the last few years, I've been designing my own plans to
build a scale B-25 Mitchell bomber.
The design was completed using SolidWorks, a 3D
program, and WinFoil. Construction of the first
prototype began on Sunday, March 6, 2005 and our first flight took place on August 11, 2007.
Despite a few "pilot errors", Precious Patty continues to fly.
Every winter, she comes back into the shop for
some design improvements.
Here's the latest news:
May 25, 2015
Welcome flyers to summer 2015. We are
getting ready to fly again.
congratulations to Alan Williamson MD for his
build of our B-25 Mitchell.
Click the picture below for a close up of this
Alan told us .. After nearly 3½ years of
tinkering in the shop, the B-25 is finally
complete except for cockpit detailing and nose
art. She had a very successful maiden flight
yesterday. I made a lot of small changes to be
more scale-like, but the basic plans were
Click here to go to HD video of his maiden
flight on YouTube.
September 14, 2014
summer, we experimented with 3 bladed
propellers. As you know, we were running
the Graupner 13x12 which provided a lot of power
but drained batteries and really heated up the
Hacker electric motors. We then switched
to Master Airscrew 13x8 which the plane flew on,
and cooled the engines, but it was a bit
sluggish. The winner was the Graupner
In the past, you could not get your hands on the
Graupner 13x10's. Then this summer we
found them on E-Bay and immediately purchased a
Then to our delight, we now see Towerhobbies.com
is selling them. Yeah TowerHobbies.com!
My apologies as I
have not update the site all summer long.
pounds is day and night difference. First
off was take-offs. Half-flap and
full power produced lift off without even using
the elevators. On our test flight on July
was done at the Sky Ranch Field and was
flawless. Great take off and great
July 7th we
flew at the Flying Electrons Scale Festival (see
pictures) and of course had our
share of problems with no other than the nose
gear. And of course, it had nothing to do
with the problems of the past - no, these were
brand new problems. Our LADO electric
conversion nose kit gave out and Tom skidded in
again for a nose landing ( it's becoming his
signature landing ). Attempting a field
repair made it worse and the next flight
finished off the nose for the season.
On the plus
side, it gave us the opportunity to purchase the
new ROBART electric conversion kits for our
WB-25 ROBART landing gear.
Arming kit from Sharprc.com worked GREAT!
June 20, 2013
our Scale B25 Mitchell is ready for flight
tests. With the improvements made back in
April, we "last minute" made the following
a. Moved the
Hacker X-80 Opto Pro 3D ESC under the cowling.
b. Moved the batteries forward, just
behind the firewall.
c. And for safety, we installed the
ArmSafe Arming kit from
With the changes, the new nose weight is now
13.5 ounces (down from 1.7 lbs.)
Batteries are charged and everything is ready
for a flight. Stay tuned for results.
April 6, 2013
looses two pounds!
An old friend, Dennis Koller of Kollercraft, WI, once
told me "the third version of your design will be
right." I scoffed at him saying, "Hey I got
computer technology". After several years and a few
design changes, well, Dennis was right and I was
winter, we were determined to resolve the nose
gear issues, and the ultimate solution was to
eliminate the 1.7 Lbs of lead in the nose.
To do this, we looked to the tail, and began
Patty's first maiden voyage had 2.5 Lbs of
lead in the nose.
Precious Patty, after year two, had 1.7 Lbs
of lead after rebuilding the tail lighter.
And this season, we expect to have little or no weight in the
nose at all !
Our last tail
was 2.0 Lbs. It was build with
basswood, lite ply and balsa and fiber glassed.
of the new tail used balsa, 1/64 lite ply sheathing, and
Solartex for covering, eliminating the
the new tail has weighed in at 1.1 Lbs,
and we did some further weight reduction by
replacing blocks of basswood in the fuselage
tail section with balsa.
these changes, we
should be able to drastically reduce
the lead nose weight.
And that will give new life to the nose gear.
here to check out the new tail.
October 8, 2012
Well, that ends
the flying season and we did not fly nearly as
much as we did last year. Circumstances
and events this summer closed our flying season
in July. Not to worry,
Precious Patty is in the hangar, awaiting next
years flying season. Just won't be with
Sky Ranch Flyers any more. We are looking
for a new home.
On the plus side,
we have opened dialog with Foxlite, who does
laser cutting, and it seems
their fees are very reasonable. Working
with their people on file formats.
Also, by mid
November, we should be offering turret and tail
glass to you builders.
July 14, 2012
Flying season came
to a quick end this year. We did some
improvements to the plane, including moving the
electronics inside the fuselage, adding lipo
batteries for the receiver, and moving the
switches inside the cockpit.
However, not being happy with the 1.3 lbs of
lead in the nose to still balance the plane, it
is being re-worked. Our plans are to
re-construct the tail assembly, and cover it
with solartex rather than sheeting and fiber
glassing it, to reduce the tail weight.
October 5, 2011
With the exception
of one bent nose wheel at the Fond du Lac
Warbirds show in August, Precious patty
continues to fly. She has 11 flights this
season, an all time best. We've
updated the Gallery with some great B-25
Mitchell photos, so check it out!
Summer is here and Precious Patty is flying
electric. She has six successful flights
this year with the electric conversion.
Click here to get the the
page or use the links to the left.
almost forgot -
Precious Patty won
"Best Scale Scratch-Built" at the Flying
Electrons Scale Festival - again. Tom didn't want to enter her as to
give someone else a chance to win, but the
judges insisted he enter.
March 2, 2011
That's right, Precious Patty is going electric!
We have been working with
Aero-model.com to provide us with the right
setup, and the parts arrived yesterday.
Watch for a new section documenting the
conversion from nitro to electric on our bomber!
November 28, 2010
Well, here's a first. This will be the
first season Precious Patty gets retired for the
without us having to fix something. Guess
Tom's flying is getting better (ha ha). We
just finished new molds for glass parts, and are
making pieces as needed. We will be
working again with Custom Model Products to do
the "production work" in a few weeks.
October 1, 2010
We've put several flights on the B25 this
summer, and other than Tom's stupid landing at
Astro Wings Charity event, the aircraft is
flying very well. However, right now,
is "grounded" as we will be attending the
SolidWorks Convention in Delevan Wisconsin on
October 6, 2010 - and we don't want Tom breaking
the bomber before the show!
July 13, 2010
replacement parts for the broken nose gear,
Precious Patty flew at the 2010 Flying
Electron's Scale Festival in Milwaukee.
Tom had two great flights and get this -
no nose wheel issues! And to end
the day with a bang, Precious Patty won "Best
June 26, 2010
Tom was conducting
flight testing June 25th and ran into control
problems as we tested the idea of mounting the
engines with a 2 degree outward thrust (bad
idea). Almost lost the aircraft all
together, and on top of that, Tom broke the nose
gear (again) while he completed an emergency
The broken nose
gear was temporarily fixed for the June 26th Air
Show, and Tom had two good flights. Check
out the pictures in the Photo Gallery (click
here). Also, watch the first minute of
this video done by Joe Fisher to see Precious
Patty flying (click
June 23, 2010
Precious Patty is
out of the shop and we are doing engine testing
this week. Talk about cutting it short!
The Sky Ranch Flyers Remote-Controlled Air Show
is just a few days away!
Tom told the boys
"we're gonna be safe on this rollout - no sense
in rushing it and loosing the bird". We
have new pictures of the plane.
Click here for a fast link to the Photo Gallery
May 20, 2010
Welcome to flying
season! We have a number of updates to
- The bomb
bay design is done, and on the bomb bay page
for a free download.
and Nose Glass production is on hold again
as we have worn out the old
balsa molds. We are creating new ones
with Repro from Freeman Manufacturing,
a resin based product that should stand up
to the pressures of vacuum forming.
- And to
throw off everyone, a new paint scheme.
With some of the later repairs we
made, we did not use the proper paint, and
some of it was gumming off. So,
Precious Patty is being repainted with a
scheme from the 1943 Torch Landings.
February 8, 2010
Work is almost
done on the re-design for the bomb bay area.
Check out the Bomb
Bay Design area. Just pictures for
now, but we should have the plans available for
a free download soon.
We have cockpit, nose, and cowling parts for
sale. Click here!
A few upgrades to the bomber this winter include
a Smart-Fly power extender (as we really don't
like Y harnesses), replacing the 4.8 volt
batteries with 6.0 volt sets, a new top turret,
and a few cosmetic repairs to the starboard
October 19, 2009
Well, we are going
to call an end to the flying season here in
Wisconsin. A few updates:
The new glass molds are progressing a well as
can be expected for
us rookies. Smooth molds
so I've sent some
more time sanding.
The Nose gear has been rebuilt with help from
the guys at
Robart.com, and it now has a 1/4 steel shear pin
compared to a
3/16 aluminum shear pin. We were concerned
about the added
strength to the gear and what it would do to the
the gear sat on, so the plane went into the shop
for a bit of "beefing
August 28, 2009
have added a new feature to the website for you
to download the plans directly from our website!
See the Plans/Drawings
page for details.
Still working on the canopies for re-sale.
We are creating new
molds that will hold up to the extreme forces of
Last, we are working on a design for the
bomb-bay for a working
system. We've got the idea sketched on
paper, and next step is
to put it into Solidworks.
Those of you that have already purchased plans
will receive the free updated
August 6, 2009
A few more flights
have taken place, and again we broke the nose
wheel. We contacted
Robart.com on the nose gear issue, and they
are sending parts to upgrade the nose gear from
a 3/16" steering (shear) pin to a 1/4"
took out too much weight on the nose, and it
wasn't flying right,
so added 3 ounces back in.
Lado-tech.net retrofit kit for the Robart
retracts are working very well.
two flights on the bomber last night, the second
of which on
landing broke the nose gear - again! We
are convinced the bird is
nose-heavy still, so we're going to take out a
few more ounces of
lead (which is strange, because it balances
I do want to compliment the folks at
ElectroDymanics for a great
product, called GlowLite, a glow plug driver
system. We've tried
other brands in the past, but this one,
"hands-down" is the best
we've seen. Had over a dozen starts, per
engine and still had
power to spare!