Guillow's Sky Launcher

[supercruiser]

A while back I bought the Sky Launcher at my local hobby shop. I think it cost $7.00. Anyway, it looked like something fun to try. Put it together and wound it up and it flew just like the picture in the instructions. A steep, arcing turn into the ground. I tried adjusting the wing like the instructions said. This made a big difference. However, it just would not gain any altitude. Removed the landing gear. 75 turns was the limit on rubber motor. Ignoring that; I wound it to 100 turns. POW. Broke the rubber motor.

Intalled a new rubber motor, 2 loops of 1/16th inch. And started over with the trimming process. This time leaving off the parachutist. For one thing the shroud lines kept getting tangled in the prop when the plane crashed before the chutist was released. Adjusted the wing, 1 inch out to the left and finally got a straight ahead climb. This is very sensitive, sliding the wing less than 1/16 inch to the left or right (of the original 1 inch movement) would cause a steep turn. This time the climb was too steep.
I shimmed the propeller support to give the model some down thrust.
Big improvement now. It was gaining altitude. Attached the glider and got a few good releases from Sky Launcher at a height of about 15 feet. That doesn't sound very high but, it was fun watching the little glider release.

Still have problems with poor glide ratio. It is like an airplane with dive brakes extended. One problem is the model was out in my shed for 2 months this summer and one wing got a terrible warp to it. I think the left wing tip is actually stalled inflight. Just now I've installed a rib under each wing in order to give them equal camber and incidence. The balsa sheet wing is over 16 inches in span and seems a bit sensitive to humidity. Maybe I'll get a chance to test fly it later this week.

[thymekiller]

Are you saying that a little guy with a chute jumps from the plane in-flight? That sounds very cool! Best of luck. I would really like to see it work. If you get it trimmed out maybe you could post a vid. How does the guy know when to jump? Sounds cool!!!

thymekiller

[supercruiser]

Yes, a little parachutist "jumps" in flight. It is a clever little mechanism based on the tension of the rubber motor of the airplane. As the motor unwinds, it's tension slackens, which causes a small hook to slide aft and then lets go of the chutist or the glider.

[kittyfritters]

Yes, a little parachutist "jumps" in flight. It is a clever little mechanism based on the tension of the rubber motor of the airplane. As the motor unwinds, it's tension slackens, which causes a small hook to slide aft and then lets go of the chutist or the glider.

This kind of mechanism used to be quite common. The first flying model that I built with my father was a Joe Ott TBM Avenger. The kit had a similar mechanism that would release the torpedo when the motor unwound. Several Sterling kits used this mechanism to drop bombs or drop tanks in flight.

The most clever use of it that I saw was a rubber powered Mustang with retractable gear. The guy that did it had quite a time setting it up when he flew it, but it looked spectacular.

There were two sets of springs one retracted the gear, the other, stronger set dropped it down. The down spring was held back by the pin controlled by the rocker on the motor peg at takeoff. The gear had working olio struts and a pin, at the top of the strut, projecting up into the hinge mounting plate in the wing locked the gear down when the weight of the model was on it. When the model ROGed the wheels dropped the struts (As I recall there was something like a ball point pen retract spring in the struts.) and the pin came out of the plate allowing the up spring to retract the gear. When the motor wound down the down spring was released lowering the gear.

I think that the only reason this worked was that the man who built it did some amazingly precise construction.

[thymekiller]

I think that I could handle the chutist, but the lg on the stang is WAY past my current skills. I thought the double rear gear drive for rubber was ponderous, but that landing gear setup is over the top.

On the chutist, is it a rocker on the rear peg or a wire hoop in the middle of the rubber strand? I like the idea of a bomb drop, but never thought of how to do it with rubber?
Thanks guys

thymekiller

[supercruiser]

I think the best way to describe it is to look at a picture. Here is the link to the Guillow product page: http://www.guillow.com/GuillowDetail.as ... amilyId=2#

If that doesn't work, just go to their main page and look under toy planes and then go to Sky Launcher and use the high resolution photo. The parachutist and the glider are slung underneath and held in place with the two small plastic hooks. The mechanism at the aft end of the rubber motor is what slides back and forth.

I'll let you know when I get my photos posted on www.virtualaerodrome.com

[thymekiller]

Thanks. Got it. I always seem to over complicate things. Its really very simple. It could easly be made to release something from inside of a fuse plane. The stick doesent have to run the full lenght, just former to former.
Thanks. Thats really cool.

thymekiller

[kittyfritters]

A motor peg rocker works the same way as the sliding saddle on the Sky Launcher. The rocker has a wire loop that goes around the motor peg with a loop on the top to anchor the rubber motor and an extension on the bottom that connects to whatever release mechanism you want to trigger. The rocker is loaded to the rear, at the top, with a small rubber band, like the Sky Launcher saddle. With the rubber wound, the top of the rocker is all the way forward and rotates to the rear as the motor unwinds. The saddle is a much simpler mechanism when you have a motor stick.

Humm...The Pearl Harbor No-Cal contest is coming up on December 7th. Maybe using Sky Launcher components I could make a Val or a Kate that drops bombs.

[supercruiser]

With the two ribs added to the wing, it now has a more consistent shape along the span. The added camber or arch stiffens the wing, also. Still had that bad warp in the left wing tip. So I soaked the tip in hot water for a few seconds and then let it dry with the wing set in the correct shape.

Did a few tests glides. MUCH improvement in glide ability. I would say that gliding distance has doubled. Powered flights will have to wait until Saturday.

[thymekiller]

A bomb dropping no-cal would get bonus points from me , for sure. Would it be a no-cal bomb?
I'm currently working on a Paul Bradley no-cal. My first of this type. A p40.

Good job on the wing issue. I think problem solveing is one of the reasons I like this hobby so much.

thymekiller

[supercruiser]

JUMPER AWAY!

Flew the Sky launcher this afternoon. I had a few minutes before sunset so I gave it a try. First, I made a few trim flights again with the glider.
Attached the parachutist and away they went. The S.L. went straight ahead to an altitude of about 15' and released the jumper. The chute was tangled slighty so he just spiraled down. The airplane still had a few winds still left on the motor and made a tight circle to the left, then landed.

I think if I adjust the rubber band tension on the slide I can get a little more altitude before release.

Started to rain, so that was it for today.

[thymekiller]

COOL Im going to have to order one.

thymekiller

[supercruiser]

I flew the Sky Launcher this weekend. Got some decent flights from it. Never did get it to fly straight ahead again. Usually makes a climbing left hand circle to about 20 feet up and releases the parachutist.

Summary of my experience with the S.L.
1. Adjusting the trim by sliding the wing to the left or right is very
sensitive. After I got it positioned correctly, drawing a line on the wing with a pencil was helpful to put the wing back in the exact same position for each flight.

2. Adding downthrust by shimming the propeller nose mount was essential
to getting the plane to behave correctly.

3. Adding the ribs to the wing was helpful with trimming but, may not have been necessary.

This was a fun experience. I think I am going to make some modifications to the airplane to see if I can get more altitude from it.

[supercruiser]

Look at www.virtualaerodrome.com, in my hangar (supercruiser) and you can see pictures of my modified Sky Launcher.