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Posted: Mon Sep 14, 2009 2:44 pm
by Moonbogg
Velocity as a goal would be pretty fun. I think we would have people with small high mix hybrids shooting toothpics though. I duno, maybe this "contest" idea has its issues, I just want to do something involving the community! Its fun.

Posted: Mon Sep 14, 2009 3:29 pm
by cannon monkey
spudamine wrote:
i think you should all shoot the same object
a golf ball or tennis ball
or even a sock
That would be no fun, we want to see people flying backwards through the air after firing rediculously heavy projectiles :lol:
thats no fun to hear about unless there a video about it

Posted: Mon Sep 14, 2009 3:40 pm
by D_Hall
Moonbogg wrote:Velocity as a goal would be pretty fun. I think we would have people with small high mix hybrids shooting toothpics though.
That's not necessarily a bad thing.

Anytime you start mucking around with a contest wherein the goal is something "impressive" you start excluding people. Most people don't have access to lathes/mills. Thus, anything that requires nice machine work is beyond them. Welding? Ditto. Or anything high energy requires access to a suitable firing range. Easy for me. Not so much for some schlub who lives in the city.

So.... Want to put your ingenuity up against that of another? Then make a contest that the vast majority of people ahve the resources to compete in.

Small hybrids shooting toothpicks may very well be the ticket.

Posted: Mon Sep 14, 2009 4:06 pm
by Brian the brain
How about this:
fastest projectile without the use of combustion or pneumatics?


Projectile being a toothpick...


That would include everyone and show ingenuity of the builder..

Posted: Mon Sep 14, 2009 4:18 pm
by Moonbogg
Brian the brain wrote:How about this:
fastest projectile without the use of combustion or pneumatics?


Projectile being a toothpick...


That would include everyone and show ingenuity of the builder..
That sounds interesting. A mechanical cannon velocity contest! About the lathes/mills, its been shown that high end cannons can be made without machine tools. Living in the city? Count me in! I live in the beautiful city of Whittier where land doesn't exist. I drive out to the desert.

Posted: Mon Sep 14, 2009 4:21 pm
by KineticAmbitions
Brian the brain wrote:How about this:
fastest projectile without the use of combustion or pneumatics?


Projectile being a toothpick...


That would include everyone and show ingenuity of the builder
That does sound like a very good idea. It involves significant ingenuity not only in developing new propulsion systems, but in building a device to measure the projectile speeds accurately enough to be admissible.

It sounds similar to my idea for a contest, which was essentially the fastest 0.2g airsoft round launcher. This standardizes the projectile, but the light weight means that launching it to decent speeds won't require tremendous amounts of energy. A toothpick would work too, but might put people without machining facilities at a larger disadvantage because of the requirement for a sabot.

Posted: Mon Sep 14, 2009 4:36 pm
by Ragnarok
I like the concept. Not sure I'd make the projectile a toothpick though, actually keeping one stable and getting a velocity measurement would be a nightmare.
Personally, if that were the competition, I wouldn't limit the projectile and would leave it up to the builder. They can go heavier if it's easier for them, but they can also go incredibly light if they'd prefer to get the velocity advantage.

Posted: Mon Sep 14, 2009 4:44 pm
by Moonbogg
If standardization were to be implemented, then an airsoft round sounds about perfect, perhaps even a BB. We already know it can be done since airsoft guns often use mechanical propulsion systems. I really like this idea of using mechanical propulsion.

Posted: Mon Sep 14, 2009 5:00 pm
by Brian the brain
Using a plastic bb sounds fine.It also eliminates railguns..

Mechanical bb launcher, measured by ...chrony?
That leaves too many people out..

now for a standard target..knocking something back a few feet or something...styrofoam penetration perhaps?

Posted: Mon Sep 14, 2009 5:17 pm
by KineticAmbitions
Using a plastic BB doesn't eliminate railguns, it would just require the use of an aluminum or copper sabot. Coilguns could be used as well, but I've not seen one that reaches high enough muzzle speeds to be competitive in such a contest. If anyone can build a railgun or ETG which could compete here, I don't see the point in excluding it.

Requiring a Chrony doesn't really leave anyone out. Any serious contestant would have one anyway, or an equivalent device.

As for targets: from what I've seen, penetration depth is not a good measure of how fast something was going. As projectiles tend to deform heavily and break apart (or even liquefy) at high impact speeds, you end up with a fairly wide-mouthed crater that isn't necessarily very deep. There's likely some relationship between mass of material ejected from the crater and the impact speed of a given projectile, but using a Chrony or equivalent seems much less prone to inaccuracy.

Posted: Mon Sep 14, 2009 5:30 pm
by Moonbogg
we could use a notebook paper penetration method. To be honest, a plastic BB being flung by a mechanical system is not going to go very fast. So we could use a box o truth method simply using sheets of paper.

Posted: Mon Sep 14, 2009 5:43 pm
by KineticAmbitions
Moonbogg wrote: we could use a notebook paper penetration method. To be honest, a plastic BB being flung by a mechanical system is not going to go very fast. So we could use a box o truth method simply using sheets of paper.
Have we agreed that it will be restricted to mechanical launchers? If only pneumatic and combustion systems are banned, then I'd expect the majority of the entries to be electromagnetic in nature. If only mechanical systems are allowed, the speeds achieved will be low in comparison, but there may be more contestants. Perhaps two separate sections so that the more common and easily achieved mechanical systems aren't massacred by the expensive yet insanely fast EM systems?

Posted: Mon Sep 14, 2009 6:08 pm
by Ragnarok
I was pretty much about to suggest the splitting of categories into mechanical and electromagnetic.

No reason to exclude either possibility, but equally, they shouldn't really be competing against one another.

Posted: Mon Sep 14, 2009 6:51 pm
by Moonbogg
Looks like this is starting to lean toward slingshots. We'll have to ban Joerg or all is lost.

Posted: Mon Sep 14, 2009 6:58 pm
by jonnyboy
D_Hall wrote:Gee... Why does it have to be hand held? ;)
He never specified how many hands. :D

EDIT- Standardizing the projectile to an airsoft bb could be troublesome because Australia banned airsoft.