Some questions about F5K or similar

[Alex Lit]

Hi! I'm a newbie in gliding, so have some simple questions. I wanna build something like wooden rc glider with wingspan about 2-3meters. It's not my first glider, i know hot to fly it, but theory isn't clear to me mostly... So:

 

1) i like V-tail, because for my opinion it can save normal weight, i thought it can combine a classic tail with ailerons,   but there's idea, that it can not work if i haven't got ailerons so do i need it or not?

2) If i need ailerons what is better solution, V-tail + ailerons or classic tail + ailerons.

Thanks for any help

[Wookman]

V tail will work as rudder elevator with dihedral and no ailerons.

Either tail configuration will work with a flatter aileron wing. 

[Alex Lit]

Wookman thanks!

[MattyB]

On R/e on the flat I always prefer a traditional cruciform tail, as they are easier to build and trim. On the slope I like V’s as they are hardier against slope abuse and you generally don’t need the rudder that much. Even so, the aerodynamic “advantages” of V’s are largely theoretical imo, especially at model sizes.

[Alex Lit]

MattyB Thanks! Do you have ailerons on all your gliders? Or it's needed only if glider has  a V-tail or classic one tail? 

Edited October 1, 2023 by Alex Lit

[MattyB]

The need for ailerons is nothing to do with the tail type. There are many factors that will influence the decision - flying style, class rules, pilot experience, aspect ratio, etc. - but tail type is not one of them.  
 

If you want a relaxed, easy to thermal model for lower wind conditions, stick with R/e (plus flaps if class rules allow them). If you want to fly in a wider range of conditions, throw in aerobatics every now and again when sport flying and/or class rules allow it, go for ailerons. 

Edited October 1, 2023 by MattyB

[Alex Lit]

MattyB Understood, thanks a lot!

[MattyB]

One small addition… On the slope, I always prefer ailerons as it enables you to pick Ip a wing quickly during the landing phase if needed. Personally I find r/e models boring and be-dimensional on the slope - if they are all you can get to fly that day you’d have been better challenging yourself off the flat instead, but if there is any level of decent slope lift available, ailerons make flying a lot more fun.

[Alex Lit]

MattyB. I never flew on slopes or on flat, i have only one glider and i'll fly it maybe next month, so now i don't understand what is less or more interesting for me. Building gliders is very interesting, but i hope flying will be too. Thanks for your opinion, i appreciate it!

[MattyB]

2 hours ago, Alex Lit said:

MattyB. I never flew on slopes or on flat, i have only one glider and i'll fly it maybe next month, so now i don't understand what is less or more interesting for me. Building gliders is very interesting, but i hope flying will be too. Thanks for your opinion, i appreciate it!

Ok… so you said earlier that you already know how to fly; what is your experience level on powered models? Are you solo standard on an aileron power model?

[Alex Lit]

MattyB. I have few trainer planes with ailerons and more than 4 simple flying wings. I crashed only 2 of them. All other planes still working, but it becomes boring and i decided try gliding. So i know how to use ailerons, but wasn't sure if it's very important part of glider.

Edited October 1, 2023 by Alex Lit

[MattyB]

Ok in that case I would go for an aileron equipped glider straight away, as a r/e(/f) thermal soarer may just bore you. 

[Alex Lit]

MattyB I'm the same opinion. And i have a new question, but not sure am i first who asked it here. What airfoil is better for glider like that? 

[MattyB]

Aerofoil choice is incredibly complicated, and can’t be looked at in isolation - you have to consider it alongside all the other factors in the overall design to achieve what you want. You also need to be able to build it straight and accurate. If you are building traditionally and want an all rounder to do a bit of everything I would suggest maybe S3021, E205 or (if you are more interested in slope aerobatics) E374 or MH32. The latter will be harder to build i wood though. 

[Alex Lit]

MattyB Understood, thanks.