100cc 330LT Rebuild

30 Mar 2017 5:46 PM | Marshall Henley

By Marshall L. Henley

In September 2016, I crunched my first 100cc plane, which I had purchased the previous year at Joe Nall, a 3D Hobby Shop 108” Extra 330LT, yellow and black. I had been practicing low hovering and then powering out and flipping it over with down elevator to an inverted harrier and then back to hover, a maneuver I always thought looked pretty cool when the 3D guys do it.

This flight, I forgot to fill up the gas, and as I flipped it over, and then throttled back up – that was it. As soon as it died, the 330LT pendulumed straight down; I had about 30 feet of altitude because of the power-out after hover. That was only enough to rotate the plane back to about 30 degrees with very little forward airspeed.

THE CARNAGE

Needless to say, something broke. Unfortunately, it was the entire fuselage. Fortunately, all other damage (wings, tail, gear, motor box) was minimal.

So, the guys there who had rebuilt big planes, like Kerry Eisenbach and Mark and Mike Stellern, started saying they thought it was fixable. I rolled my eyes mentally, thinking they were probably just trying to cheer me up… a little to much, because it seemed crazy. The plane looked awful.

However, the more they talked, the more I started to see their point. The motor looked OK. No crank shaft bend. The muffler stingers were broken, but that’s nothing that can’t be fixed or replaced. The fuselage wreckage was isolated primarily to an area starting in front of the wing tube and stopping at the back of the canopy area. I became a believer… it could be fixed!

AN OFF-PUTTING MESS

Like the Beatles song, I get by in RC modeling with a little help from my friends. I wasn’t very motivated to work on the problem, so Mark Stellern invited me to come over to his house and to bring my plane. He’d invite Mike Stellern over, who is also a great builder, and we’d get a start on things.

However, when I got there and we pulled the plane from my trailer, it looked a little worse than I remembered at the field. During the attempt to transport it, the fuselage had finally given up the ghost and cracked completely in half. I had save almost all the pieces, but things were daunting. Mike’s eyes got pretty big. If Mike was worried, I was worried.

Once in the workshop, Mike and Mark methodically identified the path forward: the “ladders” structure that makes up the fuselage was really where the damage was. If we could get enough pieces glued back in, we could pull it back into alignment, then I could take it home and beef things up before finishing repairs.

It worked! We had enough pieces, fabricating a few, to get it back to a self-sustaining ladder structure, with good alignment. I say “we” – but I was mostly watching the masters.

By the time we were done, I still had a lot of work to do on my own once I got it back home. With the holidays, a lot of business, and not feeling really confident, I found myself putting off the repairs (again). When I would see Mark & Mike, I was sheepish about my progress… “Zip, Nada, Nil” is a rotten answer to “How much progress are you making?” after guys spent four hours on a week night getting you started.

BACK AT IT

So, in January 2017, I got back at things, and during the course of the rebuild, decided to make a few improvements:

  • Install Kurt Seiter’s Holy Smokes system
  • Install the fuel and smoke tanks directly on CG
  • Paint the motor box and install aluminum baffling, ala Kurt Seiter with a cowl flap to create outflow suction. My engine had ran hot (over 300 degrees) on harriers.
  • Cut out my wheel pants to show off the “bling” wheels, ala Kerry Eisenbach.

I also wanted to keep things inexpensive, so I paid Valley Park Welding $70 to weld back my muffler stingers (instead of buying new mufflers). I repaired the cowl, with some damage still evident, if you look closely enough, and added the air flap to create outlet suction.


All in all, was able to complete all repairs for $150.





IT’S ALIVE!

On March 28th, I re-maidened the 330LT and it flew awesome. Kurt’s Holy Smokes system worked flawlessly first time out. The wheel pants looked great with Kerry-style cutouts. The engine temp never got over 150 (using telemetry) on left/rear cylinder!


That’s why RC is a “team sport.” It’s a heck of a lot more fun and productive when we work together. I’m still fiddling with the CG and found a couple of other adjustments, but I’m back to flying a really nice plane I thought I had lost.




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