GliderIreland - Ireland RC Forum - Flying Model forum in Ireland

Gliders => Scale => Topic started by: billscottni on February 08, 2020, 13:18:11 PM

Title: 1/4 Scale Ka3 Controls
Post by: billscottni on February 08, 2020, 13:18:11 PM

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?

Title: Re: 1/4 Scale Ka3 Controls
Post by: rogallo on February 08, 2020, 15:21:51 PM

Snakes in a Plane!

Title: Re: 1/4 Scale Ka3 Controls
Post by: rogallo on February 08, 2020, 15:23:09 PM

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

Title: Re: 1/4 Scale Ka3 Controls
Post by: billscottni on February 09, 2020, 12:10:41 PM

Quote from: rogallo on February 08, 2020, 15:23:09 PM

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

Title: Re: 1/4 Scale Ka3 Controls
Post by: rogallo on February 09, 2020, 12:31:16 PM

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

Title: Re: 1/4 Scale Ka3 Controls
Post by: billscottni on February 09, 2020, 13:52:29 PM

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

Title: Re: 1/4 Scale Ka3 Controls
Post by: erwan on February 19, 2020, 20:27:51 PM

I use sullivan pushrod on mine.

Title: Re: 1/4 Scale Ka3 Controls
Post by: billscottni on February 20, 2020, 10:49:05 AM

Thanks Erwan

Title: Re: 1/4 Scale Ka3 Controls
Post by: gerryb on February 22, 2020, 23:30:19 PM

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

Title: Re: 1/4 Scale Ka3 Controls
Post by: Fred on February 23, 2020, 11:49:12 AM

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 ;)

Title: Re: 1/4 Scale Ka3 Controls
Post by: billscottni on February 23, 2020, 13:36:22 PM

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

Title: Re: 1/4 Scale Ka3 Controls
Post by: gerryb on February 24, 2020, 13:42:46 PM

Hi Bill,
Some photos as promised....

Title: Re: 1/4 Scale Ka3 Controls
Post by: gerryb on February 24, 2020, 13:46:29 PM

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