C 130 Hercules Scratch Built

[WIDDOG]

Looks great I want one!

[kittyfritters]

Here are a couple of shots of it done. The top view shows the motors and the side view shows that it actually does sit on the wheels, Yes, they roll.

I got some nice glides in the back yard before the breeze came up tonight, about 40 feet from shoulder height. It's very stable. I still have to make a stooge for it, since it can't use the one from my Fokker F.36. I did make a couple of mistakes on the plans and I have redesigned it already. Powered flights will have to wait until the O.F.F.C. session on Wednesday morning. We've lost our Luther Middle School gym on the second Friday night for the next four months, but that's another story.

[WIDDOG]

Very interesting and great looking model. Can the model be flown
Outside?

[Mitch]

I love your model... I believe that stlye is called no-cal. Which means no calories or very light. But I am concerned the way your are running your motors... here are just some of the multi engine planes at West FAC 5: (Except for the experimental red Me109 prototype)

All these models have rubber motors and the motors are contained with the engine nacelle.

Even that 4 engine bomber has rubber motors in the nacelles... and it flew very well... I saw it several times... and the blue Navy plane belongs to Tom and I did the timing on that model it was a very good flyer.

Mitch

UPDATE: I see two 4 engine bombers...and they both flew with rubber motors... The little British one was very cool. With 4 little props turning away it flew very well.

NOTE: I think the P-38 is Comet or Easy Built... My Guillow model looks much more like the prototype... I need to finish that, but flying season is over in the NW.

[kittyfritters]

Mitch,

FAC rules require that all motors are completely enclosed withing the structure. That's why all those models have the motors in the nacelles. By the way, there are many ingenious solutions to containing the motors in the fuselage and still driving props in the nacelles. They just require more engineering than most people are willing to put into it.

Since a No Cal type model is a stick model with a profile fuselage attached the options are much more open. (Pun intended.) I have used this method in several models to get longer motors and it works well although one has to be careful when designing the structure, and your winding method to stand the motor strain.

This video of my Fokker F.36 will give you an idea of how it works.

https://www.youtube.com/watch?v=WUWZMqzIsI4

Also here is a photo of some of my Bristol Beaufighter No Cals.

Howard

P.S. I have a No Cal Lancaster on the drawing board. Probably about the size of that full bodied one in the photo. There are many multi-motored aircraft that have good proportions for a rubber powered model. (Tri-motors especially) I have many on the drawing board, however, I haven't had good a response about kitting them. That P-38 could also have been from Megow plans.

[kittyfritters]

Very interesting and great looking model. Can the model be flown
Outside?

Yes, like any other No Cal, if there is almost zero wind.

[Steve Blanchard]

FAC rules do not require the motors be enclosed in the nacelles. Many people have done motors going back to the stab or music wire hooks extending from the back of the nacelles. Vance Gilbert's Giant scale twin jenny has this arrangement.

Steve

[kittyfritters]

FAC rules do not require the motors be enclosed in the nacelles. Many people have done motors going back to the stab or music wire hooks extending from the back of the nacelles. Vance Gilbert's Giant scale twin jenny has this arrangement.

Steve

Steve,

You are correct. I just re-read the 2014-2015 Rule Book and found :

III-1.0 FAC RUBBER POWERED SCALE (RPS)...

L. Motor sticks may be used on multi-engine models without penalty, but props must be in their scale location.

My apologies. And that opens up some other possibilities...Hummm.

Howard

[kittyfritters]

I did not get a chance to test the C-130 under power today. The gym, a city facility, was closed for Veteran's Day. Next Wednesday will be my next opportunity.

[kittyfritters]

Well, isn't this a little embarrassing! I had my camera all charged up last night and walked out without it this morning...Not that there would have been much to see. Oh, the C-130 does fly quite well, in a straight line. Not a good thing if you are flying indoors.

That is one of the odd things about multi-motor models. People are always asking me if I have opposite rotating props on these models, and I have to tell them that they are not necessary. They don't torque roll because the multiple, parallel thrust lines cancel each other out and the trick is actually getting them to turn. You only need opposite rotating props if you are going to do aerobatics on the rolling plane, a la P-38. With 240 turns on each 1/16", flat, Tan Sport motor it flew across the length of the room and straight into the wall. For the most part it could handle this, but I did have to rebuild the nose twice this morning.

I tried combinations of drag tabs and rudder tabs, both right and left, until I finally settled on a left turn that required a drag tab on the left wing tip and a rudder tab that was nearly the full height of the rudder. This gave me a flat turn right between the basketball court side lines.

In the first flights I noticed a slight stall under power, so I put in a small, very small, amount of down thrust on all the motors. Another thing about multi-motor models is that a small amount of thrust line adjustment goes a long way. The hand launches went OK. but the down thrust would not quite let the nose get up on an R.O.G. even with 2000 turns on each motor although the fast taxi did stay between the court sidelines. I decided that it only needs the down thrust on the inboard motors. (The inboard props are clipped so that they turn faster and run out the motor before the outboard props. This allows a fast climb to near the ceiling then cruse on the outboard motors without hitting the lights.) The meeting went a bit long so the flying session was a bit short and I did not have the opportunity to take the down thrust out of the outboard motors.

Unless I fly it outdoors the next chance I will get for some video will be December 2.

[kittyfritters]

It's back to the drawing board for this one. It will fly, hand launched with a couple of hundred winds on each motor for trimming flights just fine. But, with any serious number of winds on each motor it will not R.O.G., in fact, even hand launched it settles right down to the ground.

The problem is that the wing twists down under the strain of the outboard rubber motors. My design for the wing, while perfectly adequate for a twin motor No-Cal, does not have sufficient stiffness for the four motor configuration. My Fokker F.36 worked because it was built with a "T" shaped motor stick that took all the strain of the wound rubber. The wing was not under motor stress.

The possible solutions I'm investigating are: redesign the wing to withstand the rubber tension, redesign the model to have a "T" motor stick, or redesign the model to have motor sticks in each nacelle and accept the resulting shorter motors. It has also been suggested that I re-stress the fuselage and stabilizer so that the rear hooks can be on the stabilizer.

Whatever I do to solve the problem, and I will, it will have to wait until next year. Other things take precedence.