ME- 109 rubber band size

[squirlye]

I am building a ME-109 500 series. and I want to see if this thing will fly. I read in just about every forum, that the stock green rubber band is no good for flying. So how about the rubber from 800 series sopwith camel? Can I use that instead ? How long should it be? Also how much weight is to much? I am not trying to set any records or compete. I am just bound and determind to get this thing to fly. Also I am not sure I understand the washout on the wing tips. Also how much down thrust ? Oh yea I don't really care if the plane flys in circles or not, because there are all kinds of open space to fly where I am at. Any help at all is much appreciated.

[Mitch]

Welcome to the site. Although I have built these models for a while I feel I am a novice in flying them. But looking though these posts and YouTube, some people are able to get them to fly. I would start your build and see how you do. Keep things straight and try to keep the weight down. My guess is you would want to buy some tan SIG rubber 1/4 inch. If your hobby shop doesn't have it you can get it from SIG on the internet. People seem to like Armor-All for lube. I think SIG stopped making the lube.

I hope you do well. I have the 400 series and hopefully getting ready for test flights soon. I think the 500 series would be better flyers but I like the better scale look of the 400.

Good Luck, Mitch

[Wildpig]

Look on your plans, somewhere there is a small drawing that says something like..." for longer flights use xx xxx size rubber band". I know it's there on the 900 series plans. Thats a good starting point. I have got them to fly on 2 strands of 3/16" rubber. If you are winding the rubber with your finger; keep the rubber band short.
If you have a winder (a cordless drill will work) put longer rubber in there, usually 1.5 times the hook to motor peg length. Stretch wind it to about 300 turns to begin with. Well lubricated, too.
For down thrust, just experiment. For starters you could try putting a shim about 1/2 the thickness of the 1/16th inch stringer stock.
You need to make sure it is trimmed to glide properly, first. Before any powered flights.

Weight: I think for that aircraft 35 grams is about max. for flying.

[ADW 123]

I worry about using a cordless drill as any kind of winder. i have heard stories about the winding peg slipping out and smashing through your projects and ripping up the insides. Having tried them myself, they are also a problem because you cannot "feel" the rubber when it is reaching max. revolutions. you will find you will end up breaking your rubber a lot and that tears up the inside of your plane as well. I have a hand crank winder that has a gear ratio of 1:15. Very handy.

as for washout info and lots of handy building tips, i would strongly recomend reading through THE ENTIRE build thread. take notes. Pay special attention to what Phugoid has to say. get yourself the same model plane and build it using the thread as reference.

http://balsamodels.com/phpBB/viewtopic.php?f=2&t=2215&hilit=group+build

[bitlerisvj]

Hi,
I think the ME-109 is a good choice to start with for flying. The rubber suggested in one of the posts is fine. You also asked about washout. I would build about 1/16" or 3/32" washout for this plane. That is not much, but is some and will stabilize your flights. Build the washout directly when building the wings and you should be good to go. It is a lot easier that trying to use a steamer to do it afterwards.
Good luck and regards, Vic Bitleris

[ADW 123]

I think it is best to start out with one of the high wing planes like the cesna 180 or those sorts. the WWII are often very tricky to trim for flight and the ME 109 has a small wing area compared to other WWII war planes.

[Mitch]

But the 500 series kits are all 16 1/2 inch ws. I bet the fuselage is a bit longer. In my 400 series the 109 has a shorter ws than all the others but in this series I think you will do fine.

Mitch

[ADW 123]

wing span might be the same but not wing area

[Wildpig]

I worry about using a cordless drill as any kind of winder. i have heard stories about the winding peg slipping out and smashing through your projects and ripping up the insides. Having tried them myself, they are also a problem because you cannot "feel" the rubber when it is reaching max. revolutions. you will find you will end up breaking your rubber a lot and that tears up the inside of your plane as well. I have a hand crank winder that has a gear ratio of 1:15. Very handy.


http://balsamodels.com/phpBB/viewtopic.php?f=2&t=2215&hilit=group+build

That's probably better advice, squirlye, not to use a cordless. ADW is correct. My cordless has been modified to lock in the prop hook and I only used it for short test winds. I have a BMJR winder that I use most of the time. Right tool for the job.

[squirlye]

What I should have said is, I don't know or understand what washout is. I see people talking about all the time. so if anyone wants to explain it I would appreciate it Thanks....

[Wildpig]

washout is the twist in the wing surface. If you build an airplane wing perfectly flat such as you would on a set of Guillow plans, your wing will not have any "washout" (or "washin" for that matter). If then, you take the wing and twist the tip of the wing , say the outer inch or two, DOWN: you now have some "washout" on the wing. You now have decreased the incidence (angle of the wing surface) of the wing tip. Now, suppose you take your flat wing and twist the outer inch or two , UP: you now have some "washin" on the wing tip. You have increased the incidence of the outer portion of the wing.

What does all this accomplish? Basically, it alters the way the wing stalls. Some types of wings stall first near the tips and stall last near the fuselage. Stalling near the tip can cause stability problems, such as a rapid roll or turn. By adding washout, you delay when the wingtip stalls, so that it stalls at or near the same time as the portion of the wing near the fuselage.

I don't know what level of understanding you may or may not have with aerodynamics and such, I tried not to throw strange terms at you. I'll be glad to explain further.

This page might help. Look at figure 3.4
http://www.laboratoridenvol.com/paragli ... voute.html

Here is some more information. Figure 4 shows a diagram of wing incidence.
http://raanz.org.nz/wiki/pmwiki.php?n=TM.Principals

[squirlye]

I got it now, a picture is all i needed to make the connection. Now i know why the wing tips are shaped that way on all of the A- 10s around here. They can fly super slow and turn like a mother....

[Wildpig]

Are you talking about those "droop tips" on the A-10? They do help with slow speed flight. But, aren't quite the same thing
as wing twist.
I just found this photo... it's of a wing with a serious amount of "wash-in". The wing is upside down so , this would be a "wash-in" example. Leading edge of the outer portion is UP and the trailing edge is DOWN in relation to the root rib.
http://www.ornithopter.de/english/function.htm

[bitlerisvj]

Yep, you want to be careful about using washout. It works really well on tapered wings like the ME 109, Mustang, and most low wing fighter type airplanes, even taper winged Cessnas. I don't think it is really needed for planes like Piper Cubs. Monocoupes, and others that have straight non-tapered wings. Also, if you do any kind of stunt flying, like RC or Control line where the plane gets to fly inverted from time to time, you don't want any washout, because it becomes washin when inverted. For that type of flying build the wing exactly without any washout or washin.
Regards, Vic Bitleris

Are you talking about those "droop tips" on the A-10? They do help with slow speed flight. But, aren't quite the same thing
as wing twist.
I just found this photo... it's of a wing with a serious amount of "wash-in". The wing is upside down so , this would be a "wash-in" example. Leading edge of the outer portion is UP and the trailing edge is DOWN in relation to the root rib.
http://www.ornithopter.de/english/function.htm

[squirlye]

I forgot to ask, what about the stock 5"prop that comes with the kit will it work?