How do you guys install the robart hinges? How far back from the leading edge of the control surface should the hinge point of the hinge be? The leading edges are round and sit in the trailing edge of the wing so there is no hinge gap?


Thanks

If the leading edges are round then the pin should be located away from the trailing edge the distance of the radius of the leading edge. Then rotation can occur without changing the gap. I'm doing a wing now I will post photos later.

I use nothing but the Robart Hinge Points. I've used them for many years and here's my method.

With a beveled LE on the control surface and a square TE on the fixed surface, I like to epoxy the hinge into the fixed surface, then bend the hinge 90 degrees and have it lay square against the fixed surface TE while the glue sets (be sure to fill the knuckle of the hinges with Vaseline first). Then when the control surface is glued on, push it in tight. You'll have a surface that won't bind until the bevel closes. Make sure the bevel is sufficient to give you more than the amount of deflection you want.

Dave

Here are the hinge install photos for a round leading edge. The aileron is approximately 3/4" thick, the hinge points are glued in so that the center is 3/16" away from trailing edge.

Regarding lubing the hinges before installation to keep glue from fowling the joint ...... For years I used Vaseline and even oil once then on one these forums, I read to try Crisco or other solid shortening. I did and will never go back to anything else. My method is simple .... place a small blob of Crisco in your container of choice. Melt the shortening with your heat gun, bend the hinges to their extreme, just dip a tip on the hinge line in the melted Crisco, bend back straight then set aside. Back to room temperature, the shortening is a solid again and will completely lube the whole joint. Nothing seems to stick to this stuff and being a solid, it doesn't flow around to interfere with the glue process.

Seems like such a simple thing, but when using Vaseline, I always had at least one hinge that got glue in it and was a bit stiff. Never a problem since using Crisco. Regular or butter flavor .... it all works.

That's a good tip! I always used Vaseline and would also have a few that got stuck.