2 Meter Control Line Sale Plane

Have you ever seen or heard of a 2 meter sailplane flown on control lines?

I am thinking about building a Carl Goldberg Gentle Lady 2 meter sailplane with an .049 engine and flying it on 60 ft. control lines. Wing area is 525 sq.in. at about 35 mph.

Be sure you let us know how she flys. Paul

Belated april fools right!

Must be. The Gentle Lady's wing is weak by RC sailplane standards. I can imagine what a loop will do on control lines. If this is serious, it's a serious waste of time.

Ron King

>Must be. The Gentle Lady's wing is weak by RC sailplane
>standards. I can imagine what a loop will do on control
>lines. If this is serious, it's a serious waste of time.

There is also the problem of line tension. A lightly loaded, .049 powered plane flying on 60 foot lines at 35 mph? Fortunately it should free flight if it gets loose on the lines--because it will.

The St. Louis Sam club has a CL slow flight contest. Requires a goat, an Old Time freeflight flown as a CL airplane. Winning speeds are around 20 MPH. I'm not sure of the required line length. Could be either 52 or 60 feet.

>Have you ever seen or heard of a 2 meter sailplane flown on
>control lines?
>
>I am thinking about building a Carl Goldberg Gentle Lady 2
>meter sailplane with an .049 engine and flying it on 60 ft.
>control lines. Wing area is 525 sq.in. at about 35 mph.
>
>Gary Weaver [email protected]

Ron B.
F4Fguy

Gary:
What's the area at 45 mph?

I was wondering if this would work?

I was thinking about building the wing flat instead of the usually bend UP about half way down each wing. I was also thinking about putting kevlar thread around the length of the wings over the top of the spars too. About 1/2" off set in the tail fin would give it plenty of line tension I might have to experement with that. I never did time my 1/2a airplane but it flies faster with the 6x3 2 blade prop than the 5x3 3 blade prop. I have some 60 ft lines that are light weight .012 cable.

I know a fellow his name is Eric Clutton with a PAW diesel on a Gentle Lady sailplane. Its the smallest diesel PAW makes. It seems logical that the Gentle Lady would fly fine with an .049 engine on CL.

LAST EDITED ON Apr-04-04 AT 10:44 AM (CDT)
 
The .03 is the smallest PAW. You could get this to work using monoline, as it doesn't depend on line tension to maintain control. You have to remember to that the lines add a tremendous amount of drag. Rudder offset like that is almost useless.
As an aside, the old Berkeley "Bootstraps" could be built for FF, RC, or C/L.

Jake

Hi

The only reason for dihedral or polyhedral on rudder stearing R/C sailplanes is to produce rolling forces from sideslip to bank the plane for the turn.

That is not relevant to C/L so go with a flat wing, It's more efficient anyway.

Can't see the point of it all though, just a personal preferance I guess.

I still wanna' hear the answer to Ron's question on area.

That's not the only reason. The other reason is to keep the wings level when they plane isn't turning, without pilot intervention, which is necessary with the flat wing aileron gliders.

Well that's the same thing really. If the wings are upset from level,
the resulting side slip (unteatherd dihedral models only) increases
angle of attack on the low wing, decreases it on the high wing
causing a roll effect against the side slip. In effect keeping the
wings level in straight flight.

This is not relevent to C/L as the lines prevent variation in side
slip due to banking so dihedral will not be self righting. The main
leveling force in C/L models is provided by the lines and centrapetal
force. Locating the CG in the correct position along the span is the
main key to keeping the wings straight with the lines.

OK there are other effects going on but these are the primary ones.

>Well that's the same thing really. If the wings are upset
>from level,
>the resulting side slip (unteatherd dihedral models only)
>increases
>angle of attack on the low wing, decreases it on the high
>wing
>causing a roll effect against the side slip. In effect
>keeping the
>wings level in straight flight.
>
>This is not relevent to C/L as the lines prevent variation
>in side
>slip due to banking so dihedral will not be self righting.
>The main
>leveling force in C/L models is provided by the lines and
>centrapetal
>force. Locating the CG in the correct position along the
>span is the
>main key to keeping the wings straight with the lines.
>
>OK there are other effects going on but these are the
>primary ones.
>
>Regards,
>Ken

And it took two months to get into this again?

Jake

And i,m still waiting for Gary to let us know how she flies!--Paul

>
>And it took two months to get into this again?
>
>Jake

Hi Jake

Yes I had not noticed the message I just replied too before but yesterday something went wrong and I can't see more recent messages.
This one came up near the top. That's when I noticed it.

I'm assuming it's a temporary glitch.

"Dr. Diesel" (aka Eric Clutton) is a wizard with diesel engines, an accomplished F/F contender and the US importer of PAW engines. I have a bunch of 'em, ranging from the 80TBR (.049 ci) to the .29, and they are well-made, reliable engines.

However, the engine doesn't make the airplane! You MIGHT be able to get a "Gentle Lady" to fly C/L with a PAW .049 in extremely calm air. Aerobatics? Fugeddaboudit! An exercise in futility.

I have met Eric Clutton several times he lives in Tullahoma TN about 20 miles from my house. He is an interresting person to talk to. He has a pet bird that walks around on his shoulders every where he goes. lol. Eric has a Gentle Lady with a tiny diesel engine on it I beleive its a .020 size PAW Diesel engine. About 1 minute of fuel is all it needs to get the airplane in the air. I have seen Eric hold a .049 diesel in his hand and start the engine and hold it while it runs. After about a 1 minute run he lets you touch the head of the engine which is just warm not hot. The engine has no muffle and you can talk to each other while the engine is running. It is very suprising how quiet the diesel engine runs with no muffler. I have been tempted for a long time to sell all of my glow engines and switch to diesel. It would be a big expence for me but probably worth it in the long run. Diesel has more power, uses less fuel, the same RPM's as a glow engine and will turn a larger prop than the same size glow engine. I am guessing a 15 or 20 size diesel would be about equal to an OS Max 25 glow engine. Diesel is so easy to start too. Turn the compression screw out about 1/2 turn, prime the engine, flip the prop and it starts. No glow plug to mess with and not battery. Once it starts screw the compression screw in a little to get any RPM you like. If the engine is putting out black smoke the compression is too high. The exhaust is very clean, engines runs cool and last longer than glow engines. I got the control line idea from the 2 meter sailplane from Erics Gentle Lady with the .049 engine. I figure the Gengle Lady can be built with flat wings and an .049 engine. It would be sorta like flying a very large 1/2a airplane. It should fly good at 25 to 30 mph on 35 ft lines. I sold my sailplane kit on ebay several months ago.

This sounds like fun. It kinda reminds me of my first airplanes, which I flew on 70-foot lines with an OK .29. I had control over them now and then when the lines had tension. Be sure to have very free controls so you can have some influence over where the airplane goes.

What's this with the diesel enthusiasm? Have you no sense of smell?

there used to be a young man back in Ill. that would fly a normal 1/2A Cl plane on 60ft lines. All I remember was that he would hang a C*x cylinder on the outboard wing as tip weight. Was a real site to see.

LAST EDITED ON Jun-07-04 AT 09:19 PM (CDT)
 
Would be kind of neat if you used fibre optic and sent signal, line tension wouldn't be a problem. It wouldn't be R/C, no radio, just get it to thermal and drift around on the end of your line.

I know some folks have gotten quite a laugh out of the string of posts but I quite seriously have considered something like this for a CL endurance project. I think I would a slope plane as the starting point and a diesel with resticted intake and exaust. Now just find a kid who wants to hold a record and doesnt mind flying level for 45 minutes or so.....

Bob Furr

>I know some folks have gotten quite a laugh out of the
>string of posts but I quite seriously have considered
>something like this for a CL endurance project. I think I
>would a slope plane as the starting point and a diesel with
>resticted intake and exaust. Now just find a kid who wants
>to hold a record and doesnt mind flying level for 45 minutes
>or so.....
>
>Bob Furr
>
>"See ya in the circle!"

45 minutes!?, you would have to go days, because some guys used a pressure back pack fueler with a tube feeding fuel up the lines, you could keep pouring fuel in as long as you wanted.

What exactly is the duration record?

You should be able to get this thing to stay out at the end of the lines even at 35 mph - just trim it with some outboard bank, and a little right thrust. Just don't fly it in any appreciable wind. I'd actually keep the dihedral - I don't know if you'd have enough line tension to maintain roll stability, and 2 meter long wings means a very slow roll rate. If a gust rolls the plane inwards, without the dihedral, there's nothing to keep it from coming in. The small amount of line tension you have won't be able to roll the plane level again fast enough. With the dihedral, it'll right itself even with the lines loose and assuming it's trimmed to turn to the right, it'll fly back out to the end of the lines again.

Why!!??

>Why!!??

Because?.....