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Plywood comes in large sheets, so you can cut the piece with the optimal grain orientation.
Thanks man, good to know.
Plywood comes in large sheets, so you can cut the piece with the optimal grain orientation.
That looks a whole hell of a lot better!
I think you've got it now.
Build thread in the making...maybe?
Thanks, wish me luck. Is a build thread a step-by-step featuring a model build?
What I thought, you were trying to bend the wood against the grain, not with it. Very hard, as you've found out. I think we all assumed you were trying to bend it the other way; what is considered "normal". Boiling water next time. that helps a lot!
Can I ask why you wanted to bend it this way?
What I thought, you were trying to bend the wood against the grain, not with it. Very hard, as you've found out. I think we all assumed you were trying to bend it the other way; what is considered "normal". Boiling water next time. that helps a lot!
Can I ask why you wanted to bend it this way?
1) I would go with stiffer paper, like card stock for making paper rings. Using the calculator paper will just come out heavy with all the glue being added ( no pun intended!) Cardstock, Bristol / poster board (be careful, as that stuff have a grain to it too!)
2) a thin paper wrapped around your form, then balsa wood added to it, then more paper around that to make a paper-balsa-paper sandwich (with glue) should be fairly strong for your intent. (with the balsa wood grain running parallel to the cylinder's axis)..
As for air foiling your rotor blades.. I have to ask. a helicopter rocket refers to what? helicopter recover from a standard rocket (uses blades instead of a streamer or parachute) or are we talking about a blade with a rocket motor at the tip to induce spin, therefore to induce flight..
For the latter, (which I believe you are trying to achieve) look at a propeller blade, which is essentially what you're creating. It has a twist and a airfoil. The airfoil creates the lift due to it's design. The angle or pitch also helps with the lift, but also adds to the drag. As for the twist; to be efficient, the same amount of lift should be expected along the length of the blade. So, a blade, spinning about a central point, the tip will be spinning faster than the root. (the tip travels a greater distance than a point, say, mid point of the blade for the same amount of time, therefore going faster.) So the tip really doesn't need a great pitch due to its speed to generate the same list as a point, say, a third the distance from the center of rotation. That point, a third the distance from the center of rotation, needs a greater airfoil and a greater pitch to achieve the same amount of lift as the tip. Now the real trick is figuring out how much 'pitch' you need along the length... I definitely don't know that answer, but there is math involved as well as experimentation..
First, your ring looks great. I really didn't think it was do-able. How much does it weigh?
One technique to try is to use little biscuits of balsa. Usually like a diamond shape. Cut half diamonds out of each side of the butt joint where they match up, glue the diamond biscuits to one side, then the other. They can be sanded down flush like inlays afterwards. They can also be just straight strips of balsa or fingers. Kind of like a dovetail joint, but on a straight butt joint. You might experiment with a few types. If the balsa ring was thicker you might be able to use hidden biscuits, but for that thin, not sure if you could hide them in the middle, like dowels. You could try very short thin toothpick tips. Then there is the glue dowel method, where you just poke needle holes in each side of the joint so glue can get in there and adds more contact surface, it makes a little hidden dowel of glue for a little extra strength, but that does not help you line the joint up.
Wax paper on the form would keep the glue from sticking.
there is a small amount of adhesion between white glue and wax paper(uncreased) but can be peeled off readily.
Rex
Timing is the key, the glue will bond to the wood faster. If you let the wood joint set for a bit first, then you can remove it from the wax paper while it is still a little wet and wipe off the excess.
I've been watching this thread with interest. I hope some nice pictures of the ring / glued ring will be forthcoming.
My attempts at fashioning thin, strong rings have been poor so far. Really interested in this.
If I may suggest, to glue the two ends of your ring. Instead of a butt joint, a lap joint will be stronger. 1) wrap / form your ring. ensure you have 1/2" - 1" overlap. 2) once dry & formed, sand a shallow angle into the underside of the top overlap. Sand a matching shallow angle in the top of the bottom overlap. When these two come together, you should have an angled lap joint where you but joint would be. more bonding surface..
First, your ring looks great. I really didn't think it was do-able. How much does it weigh?
BABAR BTW, I rolled a paper ring using thin calculator paper and it weighed a pretty shocking 0.4 oz. I should have used poster board, as it took 6 layers and it's still somewhat "wobbly". Anyway, a balsa ring looks way cooler if I can finally nail down a reliable technique.
Interesting.
I am guessing about 16 inches of balsa went into this radial wing. is that just the weight of the balsa strip you started with?
If you get wouldn't mind giving me the dimensions, I will weigh out an equivalent cut out from a Quaker Oats carton.
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