I am builting my own scratch built aircraft. It has a 20 inch wing span and a near fully symetrical airfoil. I would like to get an glow engine for it that isn't to heavy. What size should i get? I have seen .061 and .07 engines for sale at towerhobbies.com but are they to big/heavy for my wing/airfoil?
P.S.- If you want pictures i can get them for you.

If the .061 is too heavy you are going to need to go electric

20 inches is pretty small. Probably be better off with a .010 or .020. For a .061 or .07 you really want to be up around 32-36 inches, depending on what you plan to use the plane for.

If money is no object go over to the diesel forum and check out the pb.033 diesel ... although it may be too powerful!

Do you remember putting the prop on backwards when a small engine was too powerful for a small plane? It reduces the thrust by a fair amount.


Ed Cregger

Das Littlest Stik is 18", semisymmetrical, and uses a .049 - .051 for 2 channel R/C power. It's a wild little ride! I used elevator and rudder on mine. That might give you an idea.

Dr.1

Where could i get a .010 .020

Hi!
...First of all. Have flown R/C planes before...?

Panzer,

Where could i get a .010 .020

Unless you're building a floater and can build super-light, it's gonna be seriously underpowered with a .020.

Dr.1

Yeah i have about 20 hours on a hobbico skyfly and about 5 hours on a hobbico avistar

panzertank,

Sounds like you know a little bit about what you are doing. Care to let us know more about what you are designing?

20" wing span is rather small...and a Pee Wee .020 would be plenty of power if built in the half lb. range...unless maybe you're talking about a delta or sumpthin?

If you're thinking about an .049 to .074 then you must be designing a racer type airplane...[X(]

Have you checked out the 1/2A to 1/8A forums yet Panzer?
http://www.rcuniverse.com/forum/forumid_70/tt.htm

For the past few months i have seen all of these liitle foam flyers that dont need a lot of open area to fly. this was (sort of) what inspired me. I thought that they should have a glow powered one of these. Then after several drawings ( on Turbo CAD and on paper) i desgined a plane with a 20 inch balsa span. I have about 10 hours into it already and the wing 90% assembled and i have started the the inside structor of the fuselauge. I plan to have a full functional 4 channel airplane. 10 hours of work 'cause it was all hand sanded ( about 20 sheets). Going to use this radio with this flight pack.(below)

http://www3.towerhobbies.com/cgi-bin...=LXCZC2**&P=ML

http://www3.towerhobbies.com/cgi-bin...?&I=LXKYK5&P=7

http://www3.towerhobbies.com/cgi-bin...&I=LXTX42&P=ML

O.K....we're getting a little bit better idea of what you have in mind now...

How much wing area (in square inches ) do you have? Wing loading on a model that small is critical.

panzertank-

Sounds like a fun project. You can also get an idea of how it will fly by putting weights on it to simulate the servos and engine, and hand tossing it in high weeds to get an idea of how it will glide, etc. If it seems to be more brick like in flight, enlarge the wings some, etc.

Here is a better choice of servo if you have a couple of extra dollars over the HS-55: http://www.horizonhobby.com/Products...ProdId=JRPS185

I've used a few of the HS-55s and I like the JRs better now. I've run into quality control problems with the Hitechs too much recently.