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Pre-rebuild
At first glance the front to back
picture looked like the root tube was bent, but it was just being
forced off center by the 2 bent vertical uprights on the left side.
The main spar on the right wing was
bent and would need to be replaced. Luckily that's all for the wing,
and this is one case where it was nice to have Dacron wings verses
PolyFiber. It was very easy to just cut the fabric off the tip, slide
the sock off replace the main spar, and slide the sock back on. Only
the end of the wing had to be recovered.
PS: having Jim help made it even easier to
fix the wing.
The entire front wheel assembly needed
to be replaced, the fork that was on the plane was steel, wonder what
would have happened with a stock aluminum one?
Skinned
After removing the fabric it was
obvious two of the uprights had to be replaced since one was bent to
the point of cracking and the other (shown in picture with good tube)
was over bent. It was also interesting that when I cut the fabric
off, the two nuts on the cross bolts that hold the front two uprights
in place fell to the ground. Apparently they had never been
tightened, and since this Challenger never had the wide body
modification, the only thing holding the bolts in was the fabric
(elongated hole shown in picture with good tube). I also had to
replace the stringer tube along the bottom on the left side.
While the plane was skinned, I
referred to it as my "terminator plane"
Covering
Pre-wide body picture shows structure
prior to Jim helping add the wide body modification, and the bondo
patches on the nose cone to fill low spots from using to strong a
stripper to get old paint off. Learned using wrong stripper on
fiberglass is a really bad idea, and set me back a couple weeks
patching, and sanding. The covering pictures are pretty self
explanatory, and it was the part that scared me the most, but was the
easiest, and quickest part. "pink plane" is after two coats of
PolyBrush to seal and allow paint to stick, "gray plane" is after
three coats of Latex primer (thanks to Jims idea of using Latex).
Rebuild
Finally I get to paint it, but wait
it's the hottest most humid part of the year, and the paint takes
forever to dry "painted blue" is after three coats of blue, and four
coats of yellow. OK now quickly rebuild and I'm done ...NOT. I
noticed the holes in the rudder horns were oversized, ordered two
more. Cut and fitted the wheel struts, and noticed the brackets on
the wheel pants were different, so they didn't fit right, also noticed
one wheel was very crooked. Boy I understand why a lot of guys don't
put on the wheel struts, they're a pain to work around if you have to
take the gear legs on and off.
I thought the white dash would glare, so
I took all the gauges out, and painted it flat black, while the dash
is out I'm installing and wiring up a CB that I had in my Rotec
Rally. I'm also wiring up an electric motor to the flaperon tube to
make it easier to lower the flaps for short field landings (got info.
off internet)
PS: I, lengthened, my runway 100 feet, to
500 feet so I can land the Challenger in my backyard, the Rotec Rally
only took about 200 foot of rollout with no brakes, but a stall of
about 25mph. Hopefully with brakes, practice, and electric flaps it
will be no problem.
New Dash:
I removed the old dash and gauges to
paint it flat black for glare reduction. This is the re-installed
dash. Note the CB radio mounted lower left (Marty Spies and I talk
on CB while flying). Below the CB is a yellow toggle switch label
"Flaps", I'll soon have pictures for the motorized flap control. I
got the idea of the web, and hopefully improving on the original
design. more about that when it's completed.
motor & cover:
This picture shows the 447 motor
installed with custom cover over opening below. I also made a
heater with a cockpit controlled door using a choke cable, 4"
aluminum duct, and 4" dryer vent. My original door design was
only held on one side like a standard damper in ductwork, but it
took about 5 minutes of taxing around the yard for it to get
pulled through the prop. It's now got a shaft all the way through
the duct. secured on both sides. Hopefully I can leave heater on
year-round and use it on those chilly Summer dawn patrol mornings.
On the right, you can just see the
chrome exhaust tip on muffler. I saw on a web site where a guy
inserted a 1-1/4" sink trap cut at 90 degrees to deflect exhaust
away from prop, and tail. I didn't like restricting the exhaust,
so I used a 1-1/2" trap, and fit it over the outside, and sealed
it with high temp. silicone. Works so far.
windshield
I used the existing windshield
frame, and 3rd door, but replaced the Lexan in the windshield
since it was pretty scratched up. I added some foam tape used for
sealing truck toppers to the 3rd door, to seal the gap, and I may
do this to the other side as well if it's a problem. The foam
tape actually works to well, and I had to cover it with black duct
tape, or it tended to stick to the side of the plane. I will
probably trim the door, and windshield with black vinyl to cover
aluminum frame, and pretty it up, but that's for a rainy day.
Note white strut fairing on floor,
that's next after finishing flap control, and I think we're ready
to fly.
So far my Challenger is one heck of
a good go-Kart, engine ran great around the yard, and hopefully
soon into the air.
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Motorized Flaps:
I finally got a design that
worked well, and that I was comfortable with, after numerous
designs, and wasted aluminum trying different bracket
configurations. There are NO new holes drilled in root tube.
The existing bolt that holds the shoulder harness straps is
used, and a second bracket goes over the root tube with a bolt
through it below the root tube to squeeze it together.
Of course it turned out to be
very simple in the end. There's three pictures pertaining to
the motorized flap control, one is a close-up, with the
components numbered, that I will describe below, the second is
an overall picture, and the third is an attempt at getting a
picture of the crude gage I temporarily made on the upper
portion of the windshield. After I know it works, I'll clean up
the gage portion.
Detailed image:
1. original pushrod, shortened.
2. The body portion of an aluminum
turnbuckle that has 1/4-20 threads.
3. a piece of 1/8" x 2" aluminum
strip bent to a 90 degree angle with a hole for turnbuckle body
to pass through, and to mount motor to.
4. small piece of aluminum angle
held onto turnbuckle body with a worm gear clamp to attach
plastic strip for gage .
5. 1/4-20 all-thread with motor end
ground square for about 3 inches to slide into square motor
drive hole
6. used 12v motor from electric car
seat assembly with a square drive hole that goes all the way
through.
7. !/4" locking collar & washer at
both ends of motor drive to secure the all-thread from coming
out.
8. 1/8" x 2" aluminum bracket
(U-shaped) to hold item #3 down, and secure to root tube, with
holes drilled for bolt to pass under root tube.
9. long strip of thin plastic taped
to item #4 to act as gage in upper portion of windshield.
The most expensive part was the
6-pin 12v switch shown in the dash picture, I think it was $12.
The used motor I got free from a local dealers service
department. I actually got the whole seat assembly they were
throwing out. The turnbuckle was under $2, and a strip of 1/8"
x 2" aluminum is all you need. I'll let everyone know how it
works when I have some pictures of the plane in the air.
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