Cutting the wing control surfaces out of perfectly finished wings takes some convincing, but especially a clear mind and a steady hand. It’s a job I only do when I feel that the time is right and I’m ready for it. But even with all the precautions I usually do make one or more small mistakes, but fortunately so far never bad enough to ruin the wings.
After carefully measuring out the location of the cuts and checking the small holes in the wings that I made during building (to help locate the right place for cutting out the control surfaces) I finally felt that it was time to have a go at cutting. To cut the wings I use an old Dremel that has a brass add-on to help guide it and ensure a straight cut. I cut it along an aluminium profile that I attach to the wing in the right place using double sided tape. On the top of the wing I use a 2mm milling bit, on the bottom (where the hinge comes) a 1mm milling bit.
Once the control surfaces are cut out and cleaned from excess foam I sand back and then glass the upper protruding bit on the side of the wing (50gr glass cloth with epoxy resin). This is to ensure that the seal (which I will make later) will slide nicely and tightly under the wing. I also cut out all the openings for the servos and servo levers. Then I attach the control surfaces to the wing using good quality wax tape (not TESA, but one bought at a professional paint supply shop) and set the hinge using silicon, applied with a syringe. It’s then reinforced with bits of ebechi on double sided tape to ensure that all the control surfaces are in the right place while the silicon is curing. The silicon hinges take approximately three to four days to fully cure.