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Posted: Fri Apr 23, 2010 5:35 pm
by POLAND_SPUD
really what about a blow forward bolt seal?
I assume it's essentially what he described in his thread... (meaning it's a gun with a moving barrel)

Posted: Fri Apr 23, 2010 6:27 pm
by PVC Arsenal 17
POLAND_SPUD wrote:
really what about a blow forward bolt seal?
I assume it's essentially what he described in his thread... (meaning it's a gun with a moving barrel)
I'm not sure what you mean by a blow-forward bolt. Currently I have a reverse acting cylinder to push the barrel/bolt forwards after firing.

Do you mean some sort of free floating bolt with a slight restriction at one end so that exhaust air pushes it forward and essentially pins the shell up against a stopping block?

And yes, I know about the Revo-Semi but I don't think I have the patience to cut that pattern into a length of PVC. I'm interested in converting linear motion to limited non-resetting rotational motion. (I.E. one inch of cylinder travel yields say 15 degrees of turret rotation, and the cylinder can reset while the turrets stays in place so that the next extension of the cylinder yields and additional 15 degrees and so on)



Actually, Zippster, if you have access to a mill, a revolver mechanism might not be all that difficult. It's something to consider. If you can build the mechanism right, jams will be a non-issue. You can still use shells to simplify loading, in fact you'll probably have to since you're firing airsoft shot instead a single slug. If you decide to go that route it might be worth taking a look at these.

Posted: Sat Apr 24, 2010 12:57 am
by iknowmy3tables
Do you mean some sort of free floating bolt with a slight restriction at one end so that exhaust air pushes it forward and essentially pins the shell up against a stopping block?

yes


a rotation mechanism shouldn't be that hard, some advice the bigger the rotation mech the easier it will be to build and the more torqure it can provide so I recommend designing the rotation mech around the rotating chambers, also for ease of construction you can saw straight through the pipe and glue the the product on a sleeving pipe

limited non-resetting rotational motion. (I.E. one inch of cylinder travel yields say 15 degrees of turret rotation, and the cylinder can reset while the turrets stays in place so that the next extension of the cylinder yields and additional 15 degrees and so on)

like a true revolver ratchet and paw mech, well I think a revosemi style mech or a rotational spring with a mech to allow bit by bit rotation will be much easier to build and should operate fine

Posted: Sun Apr 25, 2010 2:37 am
by Zippster
I've been bogged down with heaps of homework and paranoid about the school-wide Nerf assassin game I'm in, so I haven't had much time to devote to this project. The purpose of this thread, at least for me, is to bounce a few ideas around people who possess greater knowledge and experience in spudding (if you can still call it that) to help me decide what design I want to model in SolidWorks and eventually create. That being said...

I'm really starting to like the idea of a revolver mechanism to cycle the shells out; it has the potential to be incredibly reliable, and I can still have the cool factor of shells without having to go around picking them up afterward. I'll have to do some research on revolving mechanisms and designs first, but otherwise it seems quite doable to me. The mill in our robotics shop is certainly big enough, but it is manual only and my skillz aren't exactly pro (although I know someone whose skills killz).

iknowmy3tables, the falling block in the lever action would come all the way down and protrude out the bottom of the gun, exposing the shell and hopefully making it fall out if you're holding the gun at a steep enough angle. It would be a finicky design, but its still worth considering.