Aileron Servo conversion - Skyartec Cessna182

[solentlife]

It had to happen ... the Skyartec Cessna uses a push-pull rod system for ailerons on one centre servo. It's a working system but the plastic 90 degree arms that take the rods to aileron horns are weak and care is needed when adjusting clevis etc.
Mine split finally and trying to superglue them - the inevitable happened .... drop got into the pivot and that was end of story.

I'd been considering separate servos out there instead of the push-pull rods and this sealed the deal.

Ideally 5gr servos or at least thin servos would suit best ... but having a few 9gr's hanging around ... I used them.

Two modifications have to be made.

a) The 90 degree link boxes out there also carry the wing strut attachments. They were cut to shape around servo and epoxied back in place AFTER the gulley was deepened to allow servo plug to pass under.
b) The wing needed hollowing out with soldering iron to sink the servo in as fas as reasonable. I use a soldering iron as this does not bremove foam - it melts it and forms a strong skin.

Hollow made ... strut fixings epoxied back in place ... One last job before fixing servos in.

Mix epoxy in the hollows .. enough to flow out and create a smooth layer for servo tape to securely stick to.

All epoxy cured ... the servos using double sided tape fixed in place ... leads led under strut fixing and along the old push-pull rod gulleys to wing centre. The factory tape haqd been lifted, stripes cut so that access to remove old rod guides ... placement of servo leads etc. could be made and then covered with factory tape. I added a strip of wide clear tape over top as well just to make sure.

The 9gr servos are just 1mm proud of the wing surface - so not so bad ..



Now waiting trial day ...

[quorneng]

Yes that method of aileron servo mounting gives a very direct friction free set up and I am sure you could have safely use a tiny 3.7g servo, particularly if the hinge is free moving.

On my solid foam wing I just carved out the foam accurately to servo size and simply glued it in, so beginning a long line of fully enclosed 'built in' servo installations.
Could be a bit tedious to replace but then with 8 planes for over two years I haven't had to!

[solentlife]

(18-11-2011 20:19)quorneng Wrote:  Yes that method of aileron servo mounting gives a very direct friction free set up and I am sure you could have safely use a tiny 3.7g servo, particularly if the hinge is free moving.

On my solid foam wing I just carved out the foam accurately to servo size and simply glued it in, so beginning a long line of fully enclosed 'built in' servo installations.
Could be a bit tedious to replace but then with 8 planes for over two years I haven't had to!

My method of creating a hole / area to carr6y something in foam is to use a soldering iron. That way you are not removing foam but heating and contracting it into a stronger skin ... keeping some of the strength via the higher density. It's a bit untidy way as the walls / heated area is never truly smooth ....

With these servos ... I mixed 5 min epoxy in the wells and then spread it out to create a smooth level surface .. and to further strengthen what is a thin flexi wing.
I then used double sided heavy duty tape ... applied before epoxy fully hard and still tacky on surface.... with tape slightly larger than servo - allowed me to press servo into the epoxy .....

I'm looking forward to test flight ...

[solentlife]

WOW .... what a difference !

The plane now tracks like on rails ............. It was good before ... now it's b**** marvelous !

To anyone thinking about HK Cessna 182 Deluxe / Skyartec .... do this mod. It's worth it.

I have 9gr servos in the wings .... but quite right from another ... lighter are fine ... if I had 5gr slim wing jobs .... I would be happy with them.