The resin on the seals of the wing control surfaces of the Orlik finally hardened out enough to sand the seals into shape (it takes 3-4 days to fully cure when you use white colourant and micro-balloons and your workshop is not that warm). Finally I had some time off and a few rainy days:  time to install the wing servos.

We’re using the usual setup for our Scale 1:3.5 gliders: Six control surfaces (3 on each wing), connected with an Integrated Drive System (IDS). We never use airbrakes on modern wing profiles – butterfly is better for landing on the slope and with modern profiles the ability to camber the full wing makes a much more performant glider.

As servos we use the Chocomotion FOX 10/10 and 8/6. We’ve used these servos on all our builds for the past few years and with many flying hours never had one fail on us. New for the Orlik are the IDS aluminium servo arms and the new glass/wood servo frames with ball-bearings kindly provided by Chocofly. The new frames are easier to install than the plastic ones we used earlier, and the aluminium servo arms are a perfect fit with the Chocomotion servos (unlike the plastic ones we used earlier) and also very robust. For the rest I used IDS pieces I still had left over from earlier builds. Rather than building the connectors on the control surfaces within the wing, I’ve placed them externally. The reason for this is that the control surfaces are quite large and I’d like to somewhat reduce the power required by the servos to move them.

Fitting all is a lot of work and careful filing all the openings. It almost took me two full days. After getting all openings and pieces to fit, I first fix all the bits with 5 minute fast-curing epoxy. At the end of the day I add slow-curing epoxy resin thickened with aerosil, to make sure that it all holds. The epoxy will cure overnight.

Next step is finishing the wiring in the wing and programming the plane….