Fault-finding airbrake servos?

[Barry_Cole]

Roger,
That is not unknown with those air brakes. Just take the corner off the brass blade, so that it clears the pin.

Better luck next time.

BC

[Jolly Roger]

Roger,
That is not unknown with those air brakes. Just take the corner off the brass blade, so that it clears the pin.

Better luck next time.

BC

I was hoping someone would suggest that. I'll trim the end of the blade to an angle and check it solves the problem.

Thanks Barry.

Rog

[Barry_Cole]

We aim to serve.



BC

[chris williams]

Swerve. We aim to swerve... (I remember your driving)

[Jolly Roger]

Now sorted.

Filed the end of the brass slider to about 20 degrees so that even if it does touch the pin, it slides over the top of it.

Will do the same to the other airbrake as a precaution.... and also because I have this thing about symmetry.

Thanks again to all for their inputs.

[B Sharp]

Symmetry? Isn't that where all good gliders go when they die?
Brian

[Jolly Roger]

Pleased it helped you Andrew. And I hope you didn't burn out 2 servos first, like me.

[John Mcnamara]

How very timely. I had a sticking airbrake on my 10 year old ASH26 on Sunday. Very annoying. Different fault though as the bottom blade was slightly buckled. Paritech put in thin wire pushrods in to close the airbrake, and without any mid-wire support. This makes them very springy and in this situation there is no danger of the servo burning out, the wire just bends. I try to close my spoilers just at touch down if I can, as it is very easy to pick up a piece of bracken or grass and this can be enough to distort something in the airbrake.
I have used some of the modern Hitec digital servos on troublesome airbrakes recently. These are programmable and one function is to go "soft" if stalled.
It amazes me that in this day and age that the commercially available airbrakes that are available, are of such poor quaility. Nylon arms that bend in the breeze, a hole in a piece of thin aliminium for a bearing, and the whole arrangement fits where it touches. It is amazing that they ever work at all. Surely there is someone out there making proper Schemp Hirth type airbrakes?
One one other point I would advise you to use two channels for spoilers for two reasons. One is the fact that John Greenfield mentioned - input charge deficiency. In some case more modern Rx's do not always have the ability to drive two servos, especially if the servos are older / another brand to the Rx, and also at the end of long wires. Getting rid of the Y lead helps, as does heavy guage wire. Secondly I am a pedant when it comes to getting my airbrakes opening exactly together, and in a linear manner. I use a curve on the input to get a liner out put position that matches the linear input of my stick. Otherwise the output curve is a "S" shape. Makes landings a lot smoother.
John