Conversion 'rubber' to 'brushless RC'?

[Tomas Dunker]

I really like Peter Fardells model The Chub (RCM&E Dec 2014) so now I am considering to enlarge the plan to do the model for a small brushless motor and RC.
Do the flight characteristics change if I enlarges all dimensions "straight off" for example 170%?
Can I use the same rib profile?

/ Tomas Dunker

[Tomas Dunker]

Some pictures to clarify my previous post.

[Norrland]

Hi Tomas,'

I really like the idea of converting small rubber powered models to RC. With todays miniature components it's rather easy. Last year I converted a 750 mm span Dumas Aeronca C3 to RC with a small (5 Grams) brushless motor. Really nice to fly even if it can't handle much of wind. More pictures and data in my album. / Per

Edited By Norrland on 24/05/2016 08:37:37

[Simon Chaddock]

Thomas

There is nothing wrong with simply increasing the size providing you take into account any structural considerations - remember bigger individual components of the same ratio of dimensions tend to be weaker.

If I have a concern it would be that wing section. As a rubber powered model it really only flies at one speed whether under power or gliding so it can use what could be described as a high lift single speed type.

Its slow flying speed is not a problem as being uncontrolled it just travels with the wind.

As an RC plane you really want to be able to keep the plane in your vicinity so with the help of the throttle it helps if the plane can be made to fly a bit faster to "get back" against any wind.

A wing section with its maximum thickness at 1/3 of the chord (Clark Y?) would give a bit better penetration ability but would still has gentle slow speed characteristics.