Cloud Clipper tail feathers question

[Tim Kearsley]

I'm building the Value Planes Cloud Clipper,  71 inch wingspan, "old-timer" style of model.  Firstly, I must say that I'm very impressed overall with the kit.  The wood seems pretty decent and the laser-cutting is superb. 

My question concerns the fin and tailplane.  These are built-up structures, using 8mm thick balsa, so fairly substantial.  The question is: What would you do at the trailing edges of the elevator and rudder?  Would you round these off or leave square?  Obviously I've shaped the leading edges of these control surfaces to allow free movement but not sure what's best at the trailing edges.

Thanks.

 

[Don Fry]

Leave the back (trailing-surfaces) square. Aerodynamics are more certain as the air breaks way cleanly and consistantly. 

[Tim Kearsley]

Thanks Don.  That was my thought also but I thought I'd check with the experts!

[Nick Cripps]

I would round the trailing edges off, it looks better.

 

There may be a benefit in square edges (or even concave) on top-level aerobatic models but for a vintage-style model like this, aesthetics beats function every day.

[Tim Kearsley]

Thanks Nick.  Interesting - two opinions, 180° opposite to each other!  I think this is one of those questions which has no "right" answer.

[Outrunner]

My Junior 60 seems to be quite happy with rounded off trailing edges. There could not be a more vice free slow flying model out there.

 

Any pictures yet of your Cloud Hopper Tim? It sounds interesting.

[Tim Kearsley]

It's a really nice kit Outrunner.  As I said in the original post, the laser cutting is absolutely first class.  The instructions are a bit sparse, with some peculiar "Chinglish" terms, but if you're not a total beginner assembly is generally fairly obvious.  I've built the fuz and the tail feathers with just the wing to be done and then everything covered.  I'll take a few pics and put them up later.  At 71 inch wingspan it's a decent size.  Mine will be electric powered, on a 3S, 2200mAh LiPo, using a motor i had sitting on a shelf.

[PatMc]

Rounded or squared whichever looks best to you. There's no aerodynamic benefit either way.   

[Engine Doctor]

Vintage style taper for the trailing edges. Square TE can help reduce flutter on faster models but your slow flying vintage model wont be racing around will it ?😉 Square TE on that will just look awful and unfinished. 

[Tim Kearsley]

As promised, a few pics of the Cloud Clipper.