1/4 Scale Ka3 Controls

[billscottni]

Finishing up my Island models 1/4 Scale Ka3 and wondering how people are controlling their ruddervators?

Pushrods
Snakes
Closed loop

Maybe wing servo's "in" the tails

What's the best option?

[rogallo]

Snakes in a Plane!

[rogallo]

Bill, I am using snakes but they are a bit sloppy.  Mind you that is the 1/3 scale one

[billscottni]

Bill, I am using snakes but they are a bit sloppy.  Mind you that is the 1/3 scale one

Not a great fan of snakes unless they can be properly supported along their length, even then the trim can vary with temperature. Seriously considering putting 2 wing servo's in the tails for more direct control

[rogallo]

Go for it, Fred said the model could do with a bit more weight for penetration.

[billscottni]

20 - 25g extra at rear is probably going to be 100 -150g at the nose so not too bad and control authority should be improved

[erwan]

I use sullivan pushrod on mine.

[billscottni]

Thanks Erwan

[gerryb]

Hi Bill,
I used Sullivan blue/yellow snakes in my 1/4 sc model and 'servo in tailplane' in my 1/3 sc model and they both work equally well as far as I'm concerned.
I have the snakes well supported along their length, so there's no slop or play to speak of.
I would suggest the red/yellow snakes are too flexible, while the black/yellow ones are too stiff for a fairly small model.
I can put up some photo in the next day or two if it would help.
 regards,
GerryB

[Fred]

Hi Bill,

Same for me, Sullivan snakes
Works a treat, but nothing stop you putting servos in the tail like the 1/3 version one

I saw your message also

[billscottni]

Thanks Fred. Now i'm completely undecided!! I'd convinced myself servo's in the tail was the ay to go, but it woul drequire some surgery on the already built tails. I have sullivan snakes in the garage, so may go that route

[gerryb]

Hi Bill,
Some photos as promised....

[gerryb]

Snakes cross over inside fuse to keep runs as straight as possible, the right hand servo operates the left hand V tail. GB