r-c-guy

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New Project - 90 powered formula one composite

Hi Guys. I have taken BobS27’s advice. I took the OS 91 VRDF engine off the 60 Mustang per his advice and am finishing a true speed project for it.

I have an old Lyle Larson Formula I composite arf from the mid 1990’s designed to fly with a Nelson 40 FIRE. I remember flying it with an OS 46 vrdf engine. It was a blast and scary fast. The only thing about it I dislike is that it is a smaller plane than I usually fly. Since my eyes are not what they used to be, I painted the wings orange and blue on the bottom surface – not cool but very visible.

I have modified it to accept either a 65 or 91 OS VRDF….. I plan on eventually putting the engine/pipe combo from the Mustang 60, which I have been writing about that has been clocked at over 180 mph by pitot tube and gps. See …page 2 or 3 or follow…

http://www.rcuniverse.com/forum/m_45..._4/key_/tm.htm

I added 5 inches to the Formula One ship, placed the gear on the fuse ahead of the wing rather than on the wing, fattened the fuse by one inch at the firewall to fit the 91, built a new cowl, and moved all of the equipment as far back as possible. The pitot tube is mounted and plumbing installed, but I won't put in the Eagletree telemetry system till I test fly her. She carries 12 oz of fuel - which should last 3-4 minutes. Plenty of time to get into trouble.

Stats for first flight: Engine: OS 91 vrdf/ prop: 11-8 apc/fuel: Omega 15% with 2 oz castor added/

I am going to attempt the first flight tomorrow if the rain stays away.

randy

soarrich

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Cool, this is going to be interesting!

Mike Connor

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You don't waste much time with your projects. Good luck.

Cyclic Hardover

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The wings are on backwards! I think we ought to have a have a contest on the what performance he gets from this thing. I will predict 188.93mph.

combatpigg

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That was my first impression,too.......the wing looks like it is on backwards. The sharp point at the LE looks like a spot where flutter could originate..

r-c-guy

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Cyclic...

I thought so too. But Lyle assured me that was not the case. Anyway, only got the engine adjusted before the monsoon came. Will try again on Thurs........

randy

soarrich

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I guess 175mph on the first day out.

rcflyer1970

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Where does it balance at, you may run out of elevator.

r-c-guy

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Hi Captb

Balance point is 2.25 inches behind leading edge of the wing. The elevator may still be too small. Only the test hop will say for sure.

bob27s

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That is a Larson F-1 Shark.

Careful on landing - with the gear that far forward, it is going to bounce all over the runway.

At 5lbs and in F-1 racing trim, its landing speed is pretty fast. This will be a bit heavier, so be prepared for that. Sounds like you have some flight time on the aircraft as it is, so you will be ok.

Control surface sizes are quite adquate. (folks these days seem to think that big control surfaces are needed - and they are, if you are flying below about 30 mph).

r-c-guy

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To Bob27S,

I agree with you Bob. In fact, at 30 mph I believe it will have all of the aerodynamic qualities of a house brick.....

randy

bob27s

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yeah, that about sums it up

daven

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Heres mine, one of these years I'll fly it

The wing is on correct!

r-c-guy

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Hi

What is in it?

randy

TIA

Dave,

Interested in seeing what your motor looks like in that plane.

If its how I'm thinking, I've got a K&B with a funky little stub of a pipe setup for sideways mount like that!

Very Loud!

LGM Graphix

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That's a cool paint scheme, but that green, ugh.......... LOL!!!!!!

daven

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The Green is AWESOME, this thing has an unbelievable paint job. He even airbrushed some grey detail around the tear drops.

Here is a picture of the motor, it is a Formula 1 Nelson .40 FIRE with straigh pipe, NO muffler at all. Its run with a small prop, on 60-65% nitro and will hurt your ears for days.

I'm a little concerned with yours R-c Guy. Adding 5" to the nose, and adding a heavy engine, are you sure that CG isn't too far forward? Did you talk to Lyle in regards to the CG?

HighPlains

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Dave, don't you mean it's a RIRE Nelson? Like these?

daven

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Your right HP, I never raced these things, but had to have one.

D

HighPlains

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You will enjoy flying that airplane and engine Dave. Start out with a 8 1/4 x 7 1/2 prop and work it until it turns 22,500. This winter I need to clean these up and rebuild for some sport flying.

r-c-guy

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HighPlains,

I did not speak with Lyle, but it balances the same as with the old 46 fan engine. I moved everything toward the tail to achieve the balance point. The additional length is mostly cowl and spinner plus 1 actual inch at the firewall.

randy

daven

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Did you get to fly it yet?

HP, I bought the plane from Lloyd Burnham, he sent several wood props with it and suggested which ones to try first and move up from there if I'm getting the R's.

BTW, this plane took 1st place at the last Formula 1 Nats in 1998 in terms of finish/paint job.

TIA

Dave, how did you get the plastic piece to stay connected onto the pipe?

daven

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The pipe is metal, just painted yellow. It is held on to the motor by an o-ring.

HighPlains

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You replace the O-ring every 6 to 10 flights. The heat kills them and the engine does not needle well when it is leaking. For a while, air shrink tubing was popular and was put over the exhaust adapter and pipe to prevent leaks. But at contests you often had to change engines between rounds, so the air shrink fell out favor with people. Also you need to hold the pipe with a spring pulled tight holding the pipe solid to a plywood pad to keep it from rotating or falling off.

I'm somewhat surprised that you could get a .90 in there and balanced, since the Nelsons and ST engines only weighed about 12 oz, and I would guess the .90 weighs nearly double that. Even with the light engines, most airplanes had the servo toward the rear of the wing saddle, and on one design I had the battery pack mounted behind the wing.

BTW, there was a thread some time back where they claimed straight line speeds of just over 200 with a racing .40 on nitro with a F1 design. I know when you put the nose down, these open exhaust engines unload far more than the 5000 rpm that they would unload on a race course. Unlike tuned pipe engines, the rpm is only limited by the aircrafts drag.