Originally Posted by Morgan Paul
That was my good belly laugh of the day. Thanks man.
I gotta agree! I'm guilty of that... but 1 in 10 work out, the rest just teach you something, and show what not to do...
I think in that design the legs would be most apt to break. It's going to flex enough side to side and forward and backward to want to snap something. Or at the least, not inspire much confidence.
Most of your stiffness comes from diameter (geometry) while breaking strength results from wall thickness. (mass) I don't know the dimensions you you are working with... but 4 three foot pieces of pipe are going to want to flex quite a bit with any wind, or if someone wants to grab hold of it. You could do it but unless you are using heavy wall, and 1 inch or larger I'd figure out a different way. I built a set of guide pipes to line up a powerboat on its trailer. Heavy, but not going anywhere, I grabbed the end and gave it all I could and it didn't complain. Sheesh, they are unsupported for all but the bottom foot and you can lay a powerboat against them...
You could get around some of the weight and flex possibilites by triangulating with some 45 degree T's... But they can be a pain in the rear to get lined up and measured properly. Choice is either to go leg to leg, or from you horizontal cross bars to the legs as corner gussets.
I would ditch the two free floating rectangles that lash on to form the peak. A T fitting and a 90 degree elbow
on each side would give you a peak. If its free floating, you get all the weight without any strength.
(Or just don't put a peak... and make it into a water
collector when it rains.
Any of your cross bars (like the double runs of pipe running horizontally under the fabric) I'd do with t's and 90 degree elbows, so that the load is carried through a different plane, rather than just adding mass... Might even keep some drips from running into the cockpit
If you choose to run them parallel and in the same plane, the further apart they are the stiffer it'll be. So if you can, a foot or so shortens the unsupported span of the legs, and stiffens each of the panels
. Probably make life difficult to climb into the cockpit
You can shorten the unsupported spans of both horizontal pipes, by using two T's, and a short stubby piece of pipe to connect them.
In my last post I was envisioning a set of hoops attached to the deck by a hinge, like a conventional bimini. So the whole mess could lay down on deck. Be heavier than aluminum
for the same strength... but no reason why you can't reach the same breaking strength as aluminum
with thicker material and a little bit of thinking. (Or a little fiberglass
I'd use the purple primer, so you can see that everything is covered... and paint
the whole structure when you are done.
, strong, or pretty. Pick any two...
Zach - Humming Weird Al's song... Dare to be stupid.