Subject:
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Re: Ping-Pong Ball Shooter
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Newsgroups:
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lugnet.robotics
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Date:
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Fri, 14 Jan 2000 02:20:16 GMT
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Viewed:
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697 times
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Jim Thomas wrote:
> I think both the catapult and slingshot would be very impressive devices.
> However, the biggest problem I see with both of these (and particularly with
> the catapult) is that they involve significant linear acceleration and
> deceleration of structures in addition to the projectile. [...]
> Built in automatic reloading is probably the most difficult aspect to
> both these designs.
I have built a catapult that fired tire rims mounted on short axles. The
reloader was the only part of the design that worked reliably, and could
probably be used to load ping-pong balls instead with a few
modifications. The basic design was two inverted beams that formed a
ramp, with bent beams above to hold the axles down. This way, when the
unit fired, the ammunition wouldn't go flying out of the loading
mechanism. The angle beam creates a "funnel" effect that makes it easy
to load new tires by dropping them in at the top of the unit. At the
bottom, another angle beam driven up and down by a cam pushes the tires
over a small "bump" created by 1x1 plates on the end of the loader. Just
after a tire is loaded the mechanism that pushes the tire out is high
enough to hold the next tire back so that it doesn't come flying out
when the catapult fires.
The design of the catapult itself was never satisfactory; I gave up on
it after ruining an 8-tooth gear trying to build up sufficient power
(described in a different post of mine).
alex
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Message is in Reply To:
 | | RE: Ping-Pong Ball Shooter
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| I think both the catapult and slingshot would be very impressive devices. However, the biggest problem I see with both of these (and particularly with the catapult) is that they involve significant linear acceleration and deceleration of structures (...) (25 years ago, 13-Jan-00, to lugnet.robotics)
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