Monday, February 20, 2012

Willow build log #1

I started the assembly of the willow, with only one hand as I received a surgery on the left hand 10 days ago. Not that easy ! I began with the wiring harmness for the wings and the fuselage. Servos connectors are crimped. I now do this for few years since I bought a crimper at the local shop. It give good result and avoid to multiply the soldering points with extension leads. At the other end, I used MPX like green connectors. They are soldered, protected with heat shrink tubes, then secured with hot glue (standard). I really encourage everybody to do this even if the connector is then glued in place, the hot glue can removed in case of problem and, unlike silicon, doesn't chimically attack the wire or the plastic. It secures greatly the soldering mechanically. I do this for 15 years and had no bad experience.

Remember, a good plane, especially for competition, is a reliable plane, you trust in any aspect. I saw too much people trying to solve a wiring problem on the slope. Securing connectors with hot glue is really a plus, and it is easy.

So how to do it ? Take 2 metal or aluminum pieces (or profile), flat of course. When the glue gun is ready, put some glue on the first metal piece. Immediatly, apply and press the connector (The side with wires & solders), then put some glue on top and put the second metal piece and press. After few minutes, you can remove the metal parts, cut the extra glue, and obtain a very nice moulded plug.

On the wing, I enlarged a bit the servos holes to ease the access to insert or remove the servos. then using the mini drill, I sanded the carbon surface to maximise the fixing. I plan to use old wing servos I found in my drawer, with missing fixing legs. So I plan to glue  them as I was doing it in the past before the invention of the servoframes. However, I cut some simple wood frames to avoid the servos to slide. to locate the exact place of the servo, I connected a fake control rod, to mark where the servos harm must be. Then I glued the wood frames with some 10 minutes epoxy from R&G. I found this epoxy to be very good, fast enough, but keeping excellent properties with time.

Let's continue with the tail: The elevator horns are not provided, only the 2 ball clevises. I used a 2mm internal diameter brass tube. First I drilled the elevator in order to install the bass tube. Be cautious during this operation, to well position the tube. Then I cut the brass tube at the right length, on both sides, and glued them in place with Cyano, and few minutes later with rapid epoxy by the internal side of the control surface. Once dry, I glued the balls at the end, using the bolt provided.

That is all for today. Tomorrow, we will continue with the installation of the servos tray in the fuselage.

1 comment: