Rib extrapolation / interpolation

[Jonathan M]

Thanks for that heads-up Peter.

At this stage I'm more interested in understanding the basic low-tech principles and just want to be able to play with a pencil, but I've parked the link to Compufoil for possible later use.

Jon

[kc]

The short answer to which airfoil to use is to use the same as another successful model in that size! Study the airfoils used on the free RCME plans and those on plans on Outerzone especially those by Phil Kraft, Joe Bridi -Ugly Stik, KwikFli ,  Kaos, Dirty Birdi etc. Compare to those used by David Boddington, Vic Smeed etc

The various fat & blunt fronted almost symmetrical sections used on Wot4, Ugly Stik, Hots, Limbo Dancer etc give the type of flying where where the speed does not pick up much in a dive - means you ( might!) get away with errors in flying which would be disastrous with other models.

Edited By kc on 30/05/2017 10:22:08

[Peter Miller]

On the subject of airfoils. I tend to favour NACA 2412 and 34213 and 3414. These are blunt leadign edge andare virtually flat from the spar back. The last two figures is the percentage thickness of the wing. Look at Ballerina etc

In passing there is an excellent website that lists the airfoil sections of hundreds of aircraft.

**LINK**

The Stuka uses Goettingen 256 from root to tip which is not included on Compufoil. but heree is a link to see it, Looks quite good being very thick and almost flat bottomed apart from a slightly raised underside at the T.E.

**LINK**