Urupema: cutting the wing control surfaces and setting the hinges

For the past few projects I always had one of my friends help with cutting out the control surfaces in the wings and elevator. It’s something that easily goes wrong and then ruins lots of hours of work on the wings. With the Corona lock-down rules, having seen it done a few times and actually having all the required tools in my own workshop I though it was time to do it myself. And it went surprisingly well, without any major hiccups, and was easier than I feared – although it does need a steady hand! I used an ancient Dremel with a 0.8mm bit for the underside of the wings (hinge) and a 1.5mm bit for the upper side of the wings. One of my colleagues in our club made a very clever add-on for the Dremel that allows you to guide it along an aluminium ruler. The rules is positioned and glued to the wing with bits of double sided tape. My mate Georg also very helpfully provided a template for cutting out the servo openings, which made it easy to do those.

After cleaning out the foam, I sanded down the upper leading edge of the wing, so it’s razor sharp, and applied a strip of 60gr glass to protect the exposed abachi wood and give the edge a bit more rigidity. Once that was hardened out I set the hinges using silicon glue. This will now need to rest for approximately 5 days, after which I can start doing the seal on the upper side of the wings.

2 thoughts on “Urupema: cutting the wing control surfaces and setting the hinges

  1. Congratulations on your first job of cutting!
    I would have felt a ton of trepidation attempting that job!


    • Thanks, so did I. One of the things I learned in the past few years of scratch-building is that everything has it’s moment. Don’t force yourself when you don’t feel ready, but don’t wait too long either. Slowly start with something easier and then work yourself into it. And take your time. No need to rush 🙂


Leave a Reply

Your email address will not be published. Required fields are marked *