Plan scaling down?

[Tin Pusher]

I have plans for a 1/12 size Mig 7 that I found on the internet. It is designed for a small glow engine. Can I reduce all measurements by 50% and still expect a model that is aerodynamic? I want to put a 280 motor in it.

[Mike Rolls]

Tim
As I understand it the Mig-7 had a wingspan of 11 metres so a 1/24 scale model is going to be around 18" in span which sounds rather small for a 280 bearing in mind that the model would only have a wing area of around 40 square inches.
I have no personal experience of models under 400 size, but the 280 motor weighs 1.5 ounces by itself and addiing other gear looks like pushing the loading up too high for so small a model.
Do you have Motocalc? A run through on that of expected weights and sizes would be helpful.
Mike

[Tin Pusher]

I will try Motocalc. Is there a formula that relates minimum wing area to weight and thrust?

[Viper Pilot]

If you do, remember that the balsa parts must be scaled down, also, and the parts aren't scaled down the same 50%.

VP

[FANMAN]

Originally posted by Tin Pusher
I will try Motocalc. Is there a formula that relates minimum wing area to weight and thrust?

What fan (if fan)

IMO, you should investigate the power system you wish to use, and see what other planes are out there. Dont get discouraged on weight, but be prepared to adjust the plane as necessary.

An extra 3/8 to 1/2 T.E, and a wingspan increase of maybe 2 inches overall, she will still look scale, and you'd be amazed at the increase in wing area. In fact, If I were approaching this project, I'd bump the tail surfaces up a tad as well, better over responsive, than not enough for a prototype. You can always cut something off easier than to add :D

Another consideration is flying capabilities, do you want a rocket, a mid range plane, or a slow flyer?

Im on a skunk works project right now, using 2 GWS EDF-50's, framed with ALL electronics, 8.2 oz :D

[Mike Rolls]

I will try Motocalc. Is there a formula that relates minimum wing area to weight and thrust?<<
Tin Pusher
One of the attributes of Motocalc is a wizard whihc enables you to input the dewsired type of performance (trainer, sport, extreme, etc) as well as size and weight.
Mike