Too-Cool Solution, in Search of a Problem
This is my very favorite mechanism.
Unfortunately, I can’t figure out a single thing to do with it, beyond Wharram’s ingenious rudder hinge. As a hinge it’s unparalleled; it’s non-metallic, very nearly friction free and costs about $2, less if you keep your eyes peeled. It lasts so long that it is routinely epoxied into place then painted over to avoid UV damage. It doesn’t mind anti-fouling paint—nor crusted barnacles. More effort is routinely taken to keep the surrounding wood from rotting than for the line itself.
But, what is it good for?
Dave
Mast pivots.
But, what is it good for?
Dave
When you need to join a flap to the trailing edge of an airfoil then you can use interlocking strips of whatever you’re using to clad the wing to make a frictionless hinge that also inhibits airflow from the high-pressure side to the low pressure side. But why would you want to do that….
When you need to join a flap to the trailing edge of an airfoil then you can use interlocking strips of whatever you’re using to clad the wing to make a frictionless hinge that also inhibits airflow from the high-pressure side to the low pressure side. But why would you want to do that….
Hmmm, there’s a possibility in that. Wingsails have been outlawed in the Moth class, as the class rules specify a single sail and a flapped wing has been ruled as two separate sails “Of course they’re separate—you can see the gap between ‘em!”
If the TE of the main element were “flexibly affixed” all along the LE of the flap—and with a textile product no less—you might prevail in introducing a wing-like sail into that class. 😉
Dave
Maybe this method could be used to attach parallelogram style pantographing akas.
Boom gooseneck….....If the boom and hinge were deep enough, it could even be self supporting…..
Rudders with no pintles, flaps with no pivots - are proaphiles becoming unhinged ?
Maybe this method could be used to attach parallelogram style pantographing akas.
In a sense, it’s just a lashing, so completely appropriate even for a traditional proa. OTOH, I kinda doubt the ancients tried pantographing beams!
Does anyone know the history of this mechanism, or did Wharram invent it? I’ve heard it called a “Cary” hinge, but those aren’t made of rope. I can’t be the only one who thinks it’s cool beans, why aren’t there more documented applications for it?
Dave
It certainly pre-dates Wharram. I remember seeing a folding clothes drying rack that used this type of hinge (albeit with webbing rather than rope) when I was a wee boy and it was old then - probably early 1940s.
I thought I’d seen it used on some viking steer board or something like that. But I couldn’t find a visual reference.
But there’s this….
Wingsails have been outlawed in the Moth class, as the class rules specify a single sail and a flapped wing has been ruled as two separate sails
So nobody has tried the P28 foiler’s wing? The internal battens are in two parts, but not the sail surface.
Obligatory on topic content: you could use that lashing for hinged foils, like Fritz Roth’s if you don’t want the bow down attitude he gets from having deliberately sloppy webbing hinges. You could use it with a tabernacle. For a cabin door.
ROTATING MAST-SHROUD ATTACHMENT. for Bermudan rig.
I think this is the problem it will solve. giving a smooth rotation of mast with plenty of clearance to the backstay.
No shackles rattling, and lightweight.
make the hinge in 2 parts for larger safety factor, which is already improved. If the hinge fails vertical strop still holding (little wild and loose but better than nothing) and vice versa.
The strop is needed for hinge alignment and to keep compression of ropes limited, it runs up into the mast at leading edge then fixed at masthead, or another method.
The ama stay and forestay/backstays could be lashed in separate holes to align forces if needed to help keep alloy hinged beak upright.
Jo.
OR THEN AGAIN, MAYBE NOT.
The attached image shows a possible use for this device as the hinge for a flap on a wing-sail. It is configured as a double hinge with an intermediate block (shown with a blue top). The intermediate block allows the double hinge to be made from the skin material of the wing without any extra joins. The closed configuration is shown at (a) with the flap deployed at (b). The image (c) shows the hinge with the intermediate block removed. As can be seen the hinge is created by cutting rectangular slots in the skin material of the wing with the slots offset from one side of the wing to the other so that skin material on one side can be pushed through the matching slot on the other side. The skin would be bonded to the sides of the intermediate block but not its ends.