RE: plastic pinned hinges how do I do this??
I do the hinges a bit different that most people. I wax the hinge line. I use a jewelers' Spure wax because it is red and I can easly see where I've put it and also I've got a ton of it from when I had my store. I like it better that the vassolie as once it hardens back up, it won't smear around. I use an xacto knife and an acohol burner to melt the wax. I scrape a bit of the wax on the blade then heat it until it goes liquid then touch the blade to the hinge line and some will weep off the blade into the hinge line. I do both sides. Use just enough to seal the hinge line, but not get on the blades of the hinges. I've also use the wax used on dental braces and it works well also.
I use 5 minute epoxy and I can set six hinge sides before it starts to kick. I use a small 1oz plastic cup and mix the epoxy in it. As stateded before, use a tooth pick, I shave one side to a flat blade, and work a bit of epoxy into the hinge slot, dip the tip of one blade in the epoxy and smear it on both sides of that blade, the push it in place. Make sure the hinge line is tight to the wing or surface you are hinging. Clean each hinge with acohol and make sure it is straight before moving to the second one. My 4*60 wings have five or six hinges per side, so one half is the maximum you can do at a time before the epoxy kicks. I would really use the 30 minute stuff for you first ones. Once the hinges are set in one surface, the epoxy the slots in the moveable surface, IE elevator or aileron, and smear a bit of epoxy on the exposed blades. Push the moveable surface onto the hinges and make sure they are fully seated with a minimum gap. Again clean up and pushed out epoxy with acohol before it starts to kick off. There will be a bit of epoxy and wax at the hinge line and I clean this off with an xacto knife after it has dried.
Keeping the hinges straight is important or you will get a very stiff, if not imovable surface. With th 1/4 scale hinges with the cotter key, I've used a piece of panio wire the size of the cotter key to go through all of the hinges while the epoxy is setting. Be careful not to get any epoxy on the wire or in the hinges and glue the wire in place. That is a mess to resolve.
The smaller hinges with the Straight pin usually have the pin mashed on the end opsite the head and are permanatly assembled. If yours are removable, you could put just a slight bend on the end of the wire to keep it from falling out. On and old trainer that I aqured, the hinges had a wire with an L end and the short leg was about 1/8" long. The pins were pushed into the hinges then a spot of epoxy was put o the tip of the L, glueing it to one surface. It seems to work well. I had to do some repairs on it and recover the elevator and rudder. I just popped the epoxy to covering off and then when I was through with the recovering, put the pins back in and spotted them again.
On the cotter keys, don't spread them very far. Just open them up with a pocket knife blade by pushing the blade into the slot The brass cotter keys bend just enough to take a slight set and they will no fall out, but can easilly be removed if needed and the re-inserted. If you open them to far, they are dificult to pull out of the hinge.
Don