8 ft SpudGun ( aka Excaliber)

queensland spudder · Thu Sep 03, 2009 2:25 am

This is my 3rd cannon i built so far, its the biggest i built so far. I have test fired it with a deo can wraped in cloth (to close up the space) and it went through 3mm plywood like a hot knife on butter

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queensland spudder · Thu Sep 03, 2009 2:27 am

Cannon specs.

Chamber size; 100mm/4 inch
Chamber length: 470mm/18.5 inch

Barrel size: 65mm/2.5 inch
barrel length 2000mm/78.75 inch

the C:B ratio is 0.628:1 , i used spray'n'pray method. Hopefully i will find that 'start ya bastard' engine stater to get that little more kick he he he.

FORE!!!! · Thu Sep 03, 2009 3:11 am

relativy simple cannon you have built there, im just wondering on how you would ignite the gas propellant? i pressume with a piezo ignitor?

other than that good work and i love the long barrel

qwerty · Thu Sep 03, 2009 3:33 am

Looks good for a first! if you upgraded to a MAPP meter you would get some decent ranges with that thing. Im sure you do at the moment

queensland spudder · Thu Sep 03, 2009 3:51 am

yes i am usinga piezo igniter to ignite the stuff. Btw im not sure wether this cannon can take Propane or MAPP it's only made out of non-rated DWV PVC pipe so im not so sure.

Boy i tell you what im predicting to get least 300m with a tenis ball when i get out to a bigger area.

BTW when i fired the cannon for the first few times and i kept getting a light black coloured smoke coming a out of the camber when i unscrewed the cap off? does anyone esle get this

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Oh here's what happend to the deo can

qwerty · Thu Sep 03, 2009 3:55 am

Im not sure about the smoke but try injecting the tennis balls full of water to get better ranges. About the MAPP gas it probably would hold up but ask an expert. Im a pneumatic person

FORE!!!! · Thu Sep 03, 2009 5:27 am

black smoke =incomplete combustion

queensland spudder · Thu Sep 03, 2009 4:04 pm

Maybe i might install a fan to mix the air better with the fuel, i think this might eliminate the smoke problem

Hubb · Thu Sep 03, 2009 4:11 pm

Chamber fans work wonders in spray-n-pray launchers. There is absolutely no better upgrade.

As far as propane / MAPP, well, I would stick with spray-n-pray on this one. It may hold up and it may not. Those aren't just DWV, they are actually designed for waste pipe (which means these are exceptionally thin).

queensland spudder · Thu Sep 03, 2009 4:25 pm

well they hold for me, someone said to wrap it in cloth tape to make it stronger , is this true.

the label said it was DWV, but the wall thickness is (for the tee) 2-3mm the glued part is 3-4mm .

For best opinion i will ask my old buddy Bubba05 who i haven't spoken to for a while and he uses the same stuff as i do with the tee thing and all that.

FORE!!!! · Thu Sep 03, 2009 5:24 pm

if you wanted to strenghten the chamber,i would suggest looking for fibre tape, its strong as fuk and will prevent little shards of plastic exploding eveywhere.

queensland spudder · Thu Sep 03, 2009 5:41 pm

kewl where can i get it , bunnings possibly.

FORE!!!! · Thu Sep 03, 2009 5:44 pm

queensland spudder wrote:kewl where can i get it , bunnings possibly.

exactly altho ive only seen it in blue there and it cost me about 4-5 bucks

queensland spudder · Thu Sep 03, 2009 5:54 pm

oh well i like blue anyway

FORE!!!! · Thu Sep 03, 2009 6:03 pm

it looks like this= http://www.spudfiles.com/forums/golf-ba ... 18646.html