Ed_Moorman

My Feedback: (1)

Here we have it, guys, the total rudimentary, simple, easy twin. And it flies pretty darn well.

I got the idea when I remembered a twin rubber thing like this. Not the twin pushers that were contest planes, but this one came in a cellophane package and you bought it at the dime store. I figured, what the heck, Flaps and I will try anything, although he nearly balked at this one.

Wing: Lanier Slasher combat plane (Notice the receiver and battery are taped into the wing)
Fuselage: Two 1/2" oak dowels
Tail: 1/4 sheet
Engine mount: 3/8 ply (2 layers of 3/16 ply-it's what we had on hand)
Engines: Magnum .28

The fuselages are a lot more flexible than I thought they would be. I thought it might get into a porpoise from the flexing, but it actually rides really well. I hit a bit of bumpy air and noticed the fuselage flexed, the the front stayed steady. Maybe it works like shock absorbers.

Everything is secured with zip-ties-a lot of zip-ties. The servos have double sided foam to hold them in place, then a zip-tie for security.

The plane is steady, stable and easy to fly. Of course, it's a junker, but, what the heck, it's a twin and it flies and it was really cheap. I would imagine you could make one using any wing available.

Ed_Moorman

My Feedback: (1)

Here's a few more, including one of the a-frame during construction. This one shows the center dowel that we use for the rubber bands.

Montague

That's a total hoot, I love it.

One of the guys here has a twin battle floyd. It's techncially legal for B class combat, but he's never actually gone for it. Pretty quick in the air though.

KidEpoxy

sweet
is the thrustline out at the same angle as the fuze lines, or 'bent in' some?

Ed_Moorman

My Feedback: (1)

No, it's not bent in. It's straight out the line of the dowels. I told my buddy, Flaps Laffert, who built it for me to use 15 degrees out thrust, but he set it at 12 deg. It handled 1 engine out OK. It is a hoot. Everyone stares at it. Maybe it's Flaps and I they are staring at thinking, "What have they done now!"

With regard to the out thrust and the loss of forward thrust, with 12 degrees out on each engine, 24 deg difference between them, I still have 97.8% of my total forward thrust. 15 degrees out would reduce the forward thrust vector to 96.6%. On most of my twins, I use 8 degrees out turhst, but still have over 99% forward thrust.

By the way, I used the fuel tubing tricks on the Mag .28s that I got off the combat web site. Seems to work pretty well. At least both of them are running most of the time.

William Robison

My Feedback: (3)

Ed:

The "fuel tubing tricks" being a short length to seal the needle valve?

Bill.

Montague

A short bit on the high-speed needle as with many engines, but on the Magnum .28's, the low speed needle also leaks air and can actually move on it's own. I've even had one fall out in flight. You can put a bit of large-diameter fuel tubing over the low speed needle housing as well, and it fixes the problem.

I posted details at www.MidAtlanticCombat.com with pictures if you care. It works on both the Magnum .25/.28 and the .15 carbs, and may work on some others. I've also seen some newer Mags coming with a different carb with a differnet low speed screw.

KidEpoxy

Lost a needle in flight?
ouch, I hate having to land with fewer parts left on the plane than when I took off
"Hey Frank, how many wheels do you see on my plane?"

Montague

Yeah, the Magnum .28 vibrates a lot, and the carb will loose parts if you don't locktite everything down. The idle stop and the throttle barrel retaining screws have also come out on me in the air. The idle stop you can just remove and put in some JB weld to seal the hole, since it's not needed anyway. I've actually had the whole barrel fall out in flight, never to be seen again. The carbs are the problem with the Magnum engines. The rest of the engine is fine.