Curved Hurricane hinge?

[StanDahl]

I'm planning my teardrop design, and what I want involves lots of curved surfaces. I'm thinking of making the galley hatch curved laterally as well as front-to-back, so the hinge would be curved laterally, like an old VW Beetle engine lid. Is this possible? If not, how could I make that joint waterproof?? Will I have to compromise and flatten that area?

[PaulC]

Not with a single piece, full width hinge it's not. Have a close look at the VW bonnet, two hinges, one either side. That's the only way you can do what you are thinking. As for waterproofing it, good luck.
Cheers
Paul

[eamarquardt]

In order for a hinge to work, all of the pivot points of the whole assembly have to be in a straight line (IE you must be able to put a straight rod through all of the points the item hinges on). If you look at a VW door or engine lid there are two pivot points and you can put a single straight rod through both of them even though the door or lid is curved. A curved hinge/pivot pin will violate this requirement and simply put, won't work as it will bind up as the door, lid, or hatch opens.

Hope this "esplains" it.

Cheers,

Gus

[madjack]

...yep, as was said, a 2 point hinge system is what is used on the Vdubs...the same could be done for a tear...there are a million profiles for rubber seals, one of which should work to seal.......
madjack

[StanDahl]

Okay, that's what I suspected. I'm thinking the two hinge suggestion could be somehow workable. I'm picturing something like the hinges on my car trunk with the big "U" shape, but that may be too complicated. Maybe just a straight horizontal piece of wood under the top of the curve with long narrow hinges mounted vertically (hinge up) may work, if the top of the lid won't dig into the bottom of the roof. I think a channel/flange arrangement or, like MadJack suggested, rubber seals could guide water away well enough. This may be doable!

[mckenney56]

I would think if you design it just like a car trunk it would be seal well enough. On my cars the seal stands up about a half inch above the car to form a trough that water runs into and down and away from the trunk opening. I don't know how to explain it too well, so just open the trunk of a car and think about where the rain water goes. Another place I've seen this in a factory sunroof on a car. The trough runs all the way around the sunroof and there was a drain hole that is connected to a tube the drains the water out. I helped figure that out when the tube got stopped up and the water started coming in the car. It was fun taking down the head liner and discovering that the tube had actually come loose from the drain.

[mezmo]

If you want to do a compound curved TD/TTT body with a hatch
the only way to waterproof it that I can see is to do a perimeter
internal gutter with the rubber weather stripping mounted on the
interior upright flange of that, bearing against the matching hatch body.

Look at a rear car trunk lid set up to see what I mean. The two
point hinging is also what is the simplest I think. Perhaps you
could repurpose a set from a junked car's trunk?

Cheers,
Norm/mezmo

[Aaron Coffee]

Just a thought but, something like trunk hinges from cars from the 30's, exterior chrome hinges, think I have seen these listed as refrigerator hinges also. The hinge pins would still need to be lined up as described previously.