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Posted: Sun Nov 15, 2009 4:20 am
by john bunsenburner
That means that if you wound tubes out of the thin rubber you could use it like tubular rubber, in the V for example, just folow it or have lots of thing layers about 2cm thick over each other...
Posted: Sun Nov 15, 2009 4:22 am
by JoergS
I don't think that thin material works well in the V. The contact with the metal rollers would kill them very soon, no matter how well polished they are.
Posted: Sun Nov 15, 2009 5:04 am
by john bunsenburner
And putting them inside a silicone tube, so that the tubber never touches any metal.
Or replacing the metal rollers with palstic ones.
Posted: Sun Nov 15, 2009 5:49 am
by JoergS
Putting them in silicone is not good, don't forget the rubber stretches. There would be friction against the silicone.
And plastic rollers wouldn't ease the damage at all, it comes from the chafing, not from the hardness of the rollers.
But I have a design that does exactly what the "V" does, with flat bands. The "H"! Did you watch this video:
[youtube][/youtube]
Video embedded by jrrdw.
Posted: Sun Nov 15, 2009 6:17 am
by john bunsenburner
No, i am thinking of a way to make flat bands be as convenient as tubular rubber... Aslo some grease would solve the friction problem in the silicone tubes...
Posted: Sun Nov 15, 2009 12:19 pm
by JoergS
I have tried all that, to no avail. Grease creates a mess as the retracting rubber splatters it around, silicone tubing slows the retraction process down very much.
Flat bands need free floating, and nothing in its way.
Jörg
Posted: Sun Nov 15, 2009 12:32 pm
by rp181
Thats interesting, perhaps it has something to do with the production of the bands (polymer chains and resiliency).
Do you think any benefits would come from multiple bands attached together, of different lengths?
example:
Order:
the fork
6" band
4" band
2" band
projectile cradle
2" band
4" band
6" band
the fork
This would seem like a staged slingshot.
Posted: Sun Nov 15, 2009 12:37 pm
by JoergS
Yes, you can do a tapering effect with tubes that way. It works. But you can not even come close to the power of thin sheets of flat rubber.
Posted: Sun Nov 15, 2009 12:50 pm
by rp181
why not combine the two?
EDIT: I meant what I said in my previous post, but each band s made up of thin bands.
Posted: Sun Nov 15, 2009 1:29 pm
by JoergS
Combining the two rubber types would create a band set with the negatives of both. You would get a slow band set that breaks early.
A chain is only as strong as its weakest link.
Slingshot: 100% Stainless Steel, Self Centering, 80 Joules!
Posted: Sun Nov 15, 2009 2:13 pm
by JoergS
Made another slingshot today (of course), further enhancing the "W" design once given to me by Bill Herriman.
Slightly smaller, nicer joints, stainless steel rotating handle, and flat bands made out of Thera Band Blue!
Great material. I hit 67 meters per second with the .75 lead ball, that is almost 81 Joules!
The two-pivot-design allow very flat forks, just flat enough to let the pouch pass. Hits on the hand are not possible with this design, because of the self centering.
Here is a video:
[youtube]
[/youtube]

Posted: Sun Nov 15, 2009 2:35 pm
by rp181
great work! youe craftsmanship is great.
Posted: Sun Nov 15, 2009 3:23 pm
by jrrdw
Because of my crossbow expierance I have to ask...How is this set up self centering?
Posted: Sun Nov 15, 2009 3:34 pm
by rp181
my guess is the handle can pivot.
or if taking centering differently, the band can slide in the sling.
Posted: Sun Nov 15, 2009 4:28 pm
by JoergS
Correct, the stainless steel handle rotates.