Aileron and flap hinges

[svyolo]

I was going to drill the aileron and flap hinge steel pieces. Sheet 14, B model. The plans show the distance to the outboard edge as 7/32. With a 3/16 hole, that is too close to the edge for standard engineering practice. Anybody every question this with Bob? The rest of the hinges, he expands the metal out to comply with edge distance requirements.

Since he also specifies 1.0" between holes, is it a loading issue with the adjoining part?

[Mark Goldberg]

I see what ypu are talking about. While I understand and respect edge margin, in this case I suspect the way the part is loaded does not make edge margin in that direction an issue. That is my guess without asking Bob. Have seen similar things before. Mark

[Cameron Ramsey]

I have seen something on this before as well. It may have been on a YouTube video possibly but in not certain. If I can find it again, I’ll post it on here.

[svyolo]

For a couple or reasons I would like to drill them a bit farther from the edge.

[Battson]

You'd want to extend the metal out, rather than move the hole inward, or the axis of the hinge would move? Beware the law of unintended consequences though, there could be interference!

Bob is an excellent engineer and designer, I am sure he did it deliberately and for a good reason.

The other reassuring thing is there are well over 100 Bearhawk planes flying, some airframes with over a thousand hours - if there was an issue with that element of the design it would have revealed itself.

[svyolo]

It is a QB so I can't move the metal. It would slightly complicate drilling the holes when I hang the ailerons and flaps.

[svyolo]

Battson;
After 2 months I can surely tell Bob knows what he is doing. I am a very impressed. It is his design so I won't change anything without his approval. After a couple of weeks I think he did what I described to make it easier to drill.