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Twisted Sticks March 2007 Newsletter
Hold on guys just a couple of more months and we will be out of our long underwear and flying. :) In order to keep up with the building spirit here are some hints. No one e-mailed me anything to put in the newsletter regarding there latest builds so without further adieu. Assorted hints for building models Installing Robart hinge points. First dry fit all the hinge points to make sure you have the no binding with the proper travel desired. If you have binding you will probably have to relieve the area around the head of the hinge point slightly. Use a Dremel with a small cutting bit and just make a small relief. Next, block up the wing so the hinge line is level. What you are going to be doing is just gluing one side of the point. The point's will all be installed bent at a 90-degree angle pointing straight down. The pins will be pushed in when glued so the metal hinge pins are all the same distance from the edge. If you are looking for a 1/8" gap then the hinge pins should all be 1/16" from the edge. Ok pull all the pins out and cover the area around each pin with masking tape or a piece of plastic with a hole in it for the hinge point to pass through. The idea here being the when the point is glued in excess epoxy will be on the plastic or tape. Many people will tell you to put a drop of oil on the hinge points. Here is another method to use. Cut up a Zip Lock bag into strips about 1/2"x 1". Then take an awl with a round point on it and pierce the center of the plastic piece. The hole is still small. Insert the side of the point hinge that is going into the surface. You now have a guard that keeps glue off of the hinge. Make up and install plastic guards for all the hinge points. Use a small round tooth pick or a cotton swab with most of the cotton pulled off and swirl some 30-minute epoxy into each hole. Take each hinge point with the guard and cover the last three barbs. Glue each hinge in keeping it at 90 degrees as discussed up above. Make sure to push in each point the same distance to the metal pinpoint. You'll know with a little practice just how much epoxy to use. Once it is dry just pull the plastic out from behind each point. Then do the other side the same way. Here is an example using oil and Gorilla glue on RCU. http://www.rcuniverse.com/magazine/article_display.cfm?article_id=269 ---------------------------------------------------------------------------------------- If you need to notch out a wing tube for a landing gear, epoxy a length of wood dowel into the notched area to take up the load. ---------------------------------------------------------------------------------------- For perfect alignment of an ARF's wing drill matching holes for a dowel behind the wing spar. Now when the dihedral brace is glued into place the dowel will prevent the wing from twisting. A method to drill a matching set of holes is to sharpen a pencil point onto a dowel. Drill the hole to fit the dowel snugly. Position the dowel so that only 1/8" sticks out. Drill a cross-hole for a piece of straightened paper clip to fit into so you cannot push the dowel inside the wing. Now paint the pointed end with a dab of paint and dry fit the wing together. Pull the wing apart and drill the matching hole. It is sometimes hard to clamp the wings together. You can usually use the two wing dowels for clamping, but what do you use for the rear of the wing? If you have not installed the ailerons you can create some clamping points. Drill a temporary hole into each wing half where the ailerons fit. Size the hole to fit a dowel. Now you have some clamping points! Use some electrical tape or masking tape to tape off an area surrounding the glue joint. Now clean up will be easy. After you've clamped the wing and it has dried pull out the dowels. Cut off two ¼" sections and use them with some epoxy to fill up the holes. ---------------------------------------------------------------------------------------- NOTE -> Anytime you use tape on a painted surface try sticking it in a hidden area to make sure the tape doesn't pull the paint off. . If it does 3M makes some low tack masking tape. ---------------------------------------------------------------------------------------- Use electrical tape or good quality masking tape to cover over the area surrounding the stab. Next use an Exacto knife to make a perfect cutout. Now when you slide the stab through the opening the epoxy gets on the tape instead of the fuselage. ---------------------------------------------------------------------------------------- Sometimes trying to cut a canopy out can be difficult especially if you have trouble seeing the lines. Use 3M trim tape and following the outline. This gives a good edge that you can see when cutting out the canopy.
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