1/3rd ka8b build log

[mick a]

one of the airbrakes would not open in flight
but would open on ground , might need stronger servos
so kept close

[Spanner]

Hi Mick
Congrats on the successful maiden, I must say the model looks very well and I also like the colours. Hope you have many a long and enjoyable flights with it.
What servos have you used to operate the air brakes? Could it be that something is binding on the brakes when they are being pushed back by the airflow? Let me know what you find just in case I have a similar issue to resolve on mine prior to painting.

Joe

[mick a]

hi joe
thanks for the compliment
it flew lovely with only needing 3 clicks of down elevator , just to make it penetrate
as fred said a bit heavier is better
it flies as full size one -sedate
i used savox mini metal gear servos for airbrakes , but like you said when wind blowing against
just not strong enough
they work fine on ground and workshop
so going to do some surgery and use standard size but stronger , or might even go servoless units
and put the thin ply top on to match wing

[Fred]

HHmmmm, before doing big surgery, I would try to give more room for the airbrakes to open, might be a simple as that. If you have 1mm around the airbrakes free, make it 2! Try to blow air on the wing, and see where exactly is the problem.

I am using 2 mini servos, and airbrakes are opening just fine on mine, but I had to open a bit more at the end of the airbrakes to operate properly (I think I have a 3mm gap)

[mick a]

thanks fred
will try that first

[Fred]

Hey Mick,

Got your message, will sort you out today!

[mick a]

thanks fred
star as ever

[mick a]

hi
here is video of ka8 doing its maiden on tow , had lots of airtime on slope
but first time towed , tow plane is wot 4 extreme with dle 40 twin

[mick a]

sorry here is link
https://vimeo.com/229495476