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Posted: Fri Oct 02, 2009 8:08 am
by Insomniac
Or, perhaps we figure out a simple device to quickly reload the cartriages completely. If we can design a gun to fire them rapidly without jamming effectively, surely it wouldn't be too much of a streatch to design a machine to replace the burst disk and projectile of multiple cartriages, one after another at a reasonable pace?

Essentially this means we will be doing the same thing that a single-chamber gun would, but instead of having the venting, reloading and refuelling mechanisms on the gun itself, we can offload them to another machine which doesn't have to be pretty, erganomic or lightweight.

I don't see why we should have to manually reload the cartriages, which seems to be what everyone assumes will be done.

Posted: Fri Oct 02, 2009 8:26 am
by jackssmirkingrevenge
Insomniac wrote:I don't see why we should have to manually reload the cartriages, which seems to be what everyone assumes will be done.
I don't see this as being much of a chore. In my mind it's inject fuel with a syringe, place burst disk, screw in retainer and pop in projectile, then hook up a compressor to the schrader at the back of the cartridge and pressurise to the required amount of psi.

Posted: Fri Oct 02, 2009 8:44 am
by Insomniac
True, but it's one of the main complaints people are having with the cartriage design. If you are going to fire lots of shots it could get tedious after a while. An auto-reloader of sorts would allow you to prepare lots of cartriages without it becoming an issue.

Of course, then you are stuck with the problem of having to reload the reloading machine every now and again :D

Posted: Fri Oct 02, 2009 9:27 am
by Moonbogg
Ease of use should be part of the design goal IMO. Syringe fueling every time? Making a whole machine for auto loading and fueling? This all sounds way too tedious and complicated. Something tells me this isn't going anywhere.

Posted: Fri Oct 02, 2009 9:44 am
by john bunsenburner
Look, i say we make the ammo and the burst disk one and the same thing like that we only have to reload ammo and not worry about the reloading of disks. To achieve this we can simply have an O-ring(heat resistant and otherwise up to the task) in which the ammo(just has to be uniform and have a flat side, also must be made from a material against which the O-ring can seal, a nerf dart for example is not of any use) rests, then we have an assembly that keeps the projectile from going out at the pressur eof the mix, so that once we ignite the mix, the projectile is foreced past what ever keeps it in and goes down the barrel. A ball bearing would be well suited for this.

Posted: Fri Oct 02, 2009 10:07 am
by Moonbogg
Are we making a BB gun?

Posted: Fri Oct 02, 2009 10:15 am
by Hubb
Moonbogg wrote:Are we making a BB gun?
Now, what kind of hybrid would that be? :lol:

Like I said before, I like the idea of cartridges, but I'm not too convinced on whether it should have a burst disk or not.

The problems, as already mentioned, with using a projectile sealing "valve" is that it needs to be strong enough to support a 10x mix, which may end up reaching around 150psi. Obviously, this would probably easier to reset each cartridge, but a way needs to be figured out to allow the projectile to support such a pressure.

This brings up the use of some sort of detent. Maybe something along the lines similar to a quick connect?

Also, I've noticed that people are taking the rate of fire to an extreme. Of course, it would be neat as hell to have 50 cartridges , but all the goals say is that the launcher needs to be capable of firing a projectile once every 20 seconds. So, why do we need a tremendously large amount of cartridges to do this. Two or three would be enough to meet the goals and still be good enough and easy enough to refill (that is, if the resetting process can be figured out).

Posted: Fri Oct 02, 2009 10:20 am
by inonickname
You can buy 1" and larger bearings..

Posted: Fri Oct 02, 2009 10:24 am
by Hubb
Why does the projectile have to be a ball bearing? Why can't it be homemade, such as out of PVC? It would make it a lot cheaper.

Posted: Fri Oct 02, 2009 10:29 am
by jackssmirkingrevenge
Insomniac wrote:True, but it's one of the main complaints people are having with the cartriage design. If you are going to fire lots of shots it could get tedious after a while. An auto-reloader of sorts would allow you to prepare lots of cartriages without it becoming an issue.

Of course, then you are stuck with the problem of having to reload the reloading machine every now and again :D
You know what, let's throw in a couple of servo motors and laser/GPS targeting module so we can just sit down with a beer and watch it in action :roll: :D
Ease of use should be part of the design goal IMO. Syringe fueling every time? Making a whole machine for auto loading and fueling? This all sounds way too tedious and complicated. Something tells me this isn't going anywhere.
It won't be any more tedious than an ordinary hybrid...

Posted: Fri Oct 02, 2009 7:19 pm
by Insomniac
jackssmirkingrevenge wrote: You know what, let's throw in a couple of servo motors and laser/GPS targeting module so we can just sit down with a beer and watch it in action :roll: :D
Then, when you finish your beer, just throw it out into the firing line for easy disposal. :lol:



On topic though, a full reloading machine is probably too exessive. Maybe just make a tool to cut a lot of burst disks of the right size easily. A giant hole punch of sorts perhaps?

Posted: Fri Oct 02, 2009 7:33 pm
by Moonbogg
So we are limited to death in ammo choices? I take it BBs and ball bearings are as far as we can venture. Sounds like a design job for Joerg, not spudders.

Posted: Fri Oct 02, 2009 9:57 pm
by POLAND_SPUD
well I think moonbog is right... let's build something that looks more less like cobra striker or cobra venom but better... we can use baseballs as ammo and it would be sooooooooooooo f###### awesome!! :D

just kidding... heh no offence moonbog I see your point here... I would never build a cartridge based system just because I am too lazy and impatient to first build all the cartridges and then reload & fill them...(not that it has take a lot of time but still)

but I would like to see how well (or bad) would they perform....

on the other hand, I would also like to see a(n) (almost) semi auto hybrid... that would be definitely something new... but I think you have to understand that it has to use smaller calibre in order to be feasible

I doubt that JSR would give up his idea easily... :wink:
so IMO it would be the best to start a poll to decide which option is more popular (or develop both designs at the same time - but I don't think that other would agree with that)

Posted: Sat Oct 03, 2009 12:19 am
by Moonbogg
I am all for cartridges or whatever, I just don't like the idea of using electrons as projectiles. I mean, is it a cannon that is going to be built, or a bb gun?

Posted: Sat Oct 03, 2009 2:38 am
by jackssmirkingrevenge
POLAND_SPUD wrote:I doubt that JSR would give up his idea easily... :wink:
so IMO it would be the best to start a poll to decide which option is more popular (or develop both designs at the same time - but I don't think that other would agree with that)
JSR is very open minded, that's why he suggested we put the idea to a vote ;)
I would never build a cartridge based system just because I am too lazy and impatient to first build all the cartridges and then reload & fill them...(not that it has take a lot of time but still)


I think this is what puts most individuals off the idea of cartridge launchers, but don't forget this is a community project. Once we have the basic dimesions of a breech and the location of firing points, anyone can make their own cartridge within those paramaters and one launcher would be a potential test bed for a variety of international efforts. I think we're missing the bigger picture here!
I am all for cartridges or whatever, I just don't like the idea of using electrons as projectiles. I mean, is it a cannon that is going to be built, or a bb gun?
:D :D :D

I'm with you, this should be at the very least 1/2" bore. Not too big though, for logistical purposes. Personally I would say 3/4" is a good compromise.

The projectile sealing idea is slightly limiting in terms of projectiles, perhaps we should centre around a commonly available sabot system - 12 gauge shotgun sabots. Strong enough for the 10-20,000 psi of hot gas a scattergun generates, cheap, light and almost universally available - plus they're a perfect fit in a 3/4" barrel :)