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Help with motion direction changing for revolver type cannon

Posted: Sat Aug 01, 2009 4:35 pm
by 30cal man
ok in my quest for a awesome paintball shotgun ( and by shotgun i mean something with shells that shoots alot of little 6mm paintballs at once 25-50 a shot) i have came up with a design i wan to use for the firing mechanism and although it will have a revolving chamber i want it to be pumped to cycle the cylinder which is where the problems lie i can not figure out how to take the back stroke of the pump and make it rotate a cylinder a 1/8 or so of a turn the return stroke can be used aswell but docent have to be but i want a pump because of the mechanism i have decided to use as its power/valve any help on this will be muchly appreciated thanks

Posted: Sat Aug 01, 2009 4:42 pm
by Hotwired
All been done before ^^

http://en.wikipedia.org/wiki/Webley-Fos ... c_Revolver

Solar has a very similar system to rotate the spindle of his Eclipse cannon but you don't see it because it's internal, his is actually operated by a pneumatic cylinder which (presumably) pushes a pin along the grooves to turn the spindle to the next cartridge.

Instead of the Webleys automatic system or the Eclipses pneumatic system you use a manual system.

Posted: Sat Aug 01, 2009 5:28 pm
by boom shtick
can you show us what you`ve got o` your plans so far?

Posted: Sat Aug 01, 2009 8:25 pm
by hi
http://science.howstuffworks.com/revolver2.htm

take apart a revolver if you can get your hands on one. They are very simple. all you need is to add a pump to the hammer and you've got yourself a revolving shotgun.



the advice i would like to give for the cylinder is to take some foam board (from hobby shop or insulation foam from hardware store, if they ask tell them its for a model airplane) about 1'' thick and use a compass and marker to make a circle, cut it out with a razor/exacto knife then draw a perfect cross on it, then rotate the board 45 degrees and do it again. that will give you a perfect circle as well as 8 spots to evenly place the chambers. build two of these, drill the holes ( I would use 1/2'' pipe for the chambers) and glue them together using foam safe epoxy, then sheet it with 1/32'' balsa wood, also from a hobby shop. i would sheet it with two layers, then cover it with CA glue.

for the notches that the pawl lifts the cylinder with can be made of brass tube, again, from a hobby shop. the pawl it self can be made of sheet metal, use snips to cut it.

that is probably the easiest way to make a cylinder without a lathe and expensive machinery. ive never done it, but i don't see why it wont work.

Revolvers are very simple, but unless you can take one apart i dont know how I can explain how it actually works, but believe me when i say its simple.

sigh, after that little brain storm now i want to build one...

Posted: Sat Aug 01, 2009 9:04 pm
by inonickname
(hi), what I'd do with that would be to make the foam mold of exactly what you want, then cast it with aluminum (lost wax/foam replacement casting).

That's only if you have the stuff to do it with..

Posted: Sun Aug 02, 2009 7:31 pm
by 30cal man
that webley-fosbery is awesome but i cant find anything about how it works and even though i wanted it to be pump because i thought it would be easier to accomplish a semi auto motion would be helpfull so far i have a vlave and a way to fire it semi auto but in need of a simple way to turn the cylinder i seen the revo semi but dont like the fact that the pump shoots it