I am building a TF Spitfire and followed the thread called spit fire build. In the thread it shows more scale like hinging where the stab, rudder and airlerons are rounded instead of beveled and the fixed surfaces are extended with light ply to create a pocket of sorts to hide the hinges. Can anyone show me more detail on this change.. It would seem to me that that the hinging point would have to be recessed back into the control surface so the distance would be critical at each point. I am assuming the set back would be equal to 1/2 the diameter but since the control surfaces taper would this distance be the same or different for each hinge along the length of each control surface. Robarts hinges are used for this application, I can see that. Also, how do they make the pocket for the hinge to swing in moving parts, as keeping this perfect would seem imperative for a good finished look.

Thanks for any help with this,
Randy

Yes the hinge point must be set back into the aileron or flap. The surface must be slotted to allow free movement at the hinge points. The hinge pivot points must be in line with each other and it is ok if they are set back at different distances. I would use G-10 for the extension of the fixed part of the wing instead of 1/64" ply since it does not warp. A good source for that is www.fliteskin.com.

Thanks for the info.. how is the best way to cut the tapered pockets for the hinges? One way that comes to mind would be to cut slot in the leading edge to the depth of the center of the hinge then make fillers with the correct angles. Is there a better way?
Regards,
Randy

I make my own hinges using a Dave Platt method. He also sweeps the trailing edge of the stab. I guess it would be 1/2 the difference of the taper. This gives a perpendicular line to the datum after the rear sheeting is on the stab. I usually use thin ply as my center and make a cut out for each music wire pin. The fiberglass G-10 or PC board is about 1/4 x 1-1/2 or so for a 17 pound 80" plane. I just cut the slot in the control surface kind of more than needed and cover the extra with sheeting. I like more movement than required.

Carl

Thanks again.. not sure what the Dave Platt Method of making hinges is though, lol...where can I find this info?

Best regards,
Randy

Dave Platt makes a series of videos called the Black Arts. He has several series including construction and fiberglassing, painting and detailing, advanced building, scratch building, and more. In these, he shows his technique for custom hinges for control surfaces.

http://www.daveplattmodels.com/

Scott

If Platt has a plans for a plane that you like its very worth while to build from his plans. There is a lot that can be applied to all models. His videos are quite useful also. Just make a core for your control surface and cut a T where your hinges will be. Place stock over the area on one side and fit the hinge. Then do the other side. I cut the hinge slot for more travel than required. Think light in the tail. Use what ever method you like to build out the control surfaces. Ribs for covering, ribs for sheeting or solid light balsa. I make the control surfaces before I cover the sheet the stab surface. Sheeting covers the slots nicely. It is possible to use a long piece of music wire to replace all the pins. This enables removall of the control surface for finishing.

Carl