First Cannon

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
moze304
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Joined: Sat Mar 22, 2008 9:19 am

Sat Mar 22, 2008 10:50 am

well, here it goes......After a week of studying this website and the burnt latke website, and my fiance tellin me i'm childish...this is what i came up with...its almost finished...i was gonna go with the camo paint like that one guy on here did with the leaves and stuff (good job man!)...but i had a bunch of garbage pail kid stickers lying around and i thought it would look kool....i'm using meterd propane...i think i'm gonna feed it in thru the endcap with a shrader valve. i still have to house the wires for the fan and ignitor..so its not completely finished yet..should be done by later today, and i'll post a pic or 2 of the finished product...i have a feeling i'm hooked now, and will probably build another, and another,.......see where i'm going?..lol...i know i should have placed the ingnitor screws where its double layered, but i kept reading that its better to place the ignition in the middle of chamber...anywayz here are as much specs as i can think of for the moment...

SPECS:
1. cost- @40-50$
2. combustion chamber- 4"x20" (at tapered part of reducer)
3. barrel- 2"x60" (i plugged in numbers in http://www.burntlatke.com
and came up with something around 1.25:1)
4. 80mm chamber fan (ripped apart an old computer, it had an 80mm
brushless fan, and also a 40mm brushless fan also in it,
5. bbq universal ignitor (push-button, got it from wal-mart for $9 and some change
6. bought wire from lowes (like 14 cents per foot)

thats all i can think of at the moment. i have to put a bolt at the beginning
of barrel to stop the potato from falling into chamber. i sanded the end of the barrel to help cut potato.

i pretty proud of it, being my first...i hope this may spark some design ideas for someone out there......enjoy!
Attachments
took picture looking in thru top end of chamber
took picture looking in thru top end of chamber
looks really clean in person
looks really clean in person
almost finished
almost finished
drilled holes in handle, and wired up to ignitor button.
drilled holes in handle, and wired up to ignitor button.
from the back.
from the back.
shrader valve, i saw someone else on here with one...works good!
shrader valve, i saw someone else on here with one...works good!
finished gun
finished gun
Last edited by moze304 on Mon Mar 24, 2008 4:44 pm, edited 1 time in total.
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bigbob12345
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Location: Mercer Island,Washington

Sat Mar 22, 2008 10:59 am

Very nice job for a first
You could always make that barrel a little longer.
All it needs ia a better ratio and a propane meter and it would be an extremely nice gun(it already is a nice gun but that propane meter will be that finishing touch)
moze304
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Joined: Sat Mar 22, 2008 9:19 am

Sat Mar 22, 2008 11:05 am

thanks bob. i might end up doin that (longer barrel). i work for the gas company so most of the parts for the propane set-up, i should have lying around somewhere...all these numbers for figuring out how much gas confuse me a little tho...i downloaded the fuel calc...i'll try to use that to figure it out if i can understand it...if not...it'll have to be trial and error till i get it right i guess.
OuchProgramme
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Joined: Sat Jan 12, 2008 7:30 pm

Sat Mar 22, 2008 11:22 am

Wow, nice job on collage.

Retrooo
moze304
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Mon Mar 24, 2008 4:56 pm

added pictures of pretty much finished gun...i shot 2, 5lb bags of potatoes yesterday....i'm convinced that these are not toys...i think i was gettin at least 200 yards.. shot clean thru a piece of plywood without even knocking it over...the gun held up pretty good except for one of the connectors for the fan wires snapped....used electrical tape to tape wire over the bolt as a quick fix, and kept on chuckin!....thats why the tape is wrapped around the end fitting....i don't have a psi meter...it took a while to get it right...i unscrewed the flare piece off of the propane torch fitting, and clamped a 1/4 inch gas line hose on to it...other end of hose has an air chuck...just connect that to shrader valve on endcap....open gas valve for ONE second....run fan 10 seconds and it shot pretty much every time....i have an on off switch...for the fan i have to wire it up and figure out where to mount it with the battery and its pretty much done...i do have one question tho...do you get any build up on the screws inside the chamber from the combustions? i noticed i'm not seing a spark every time i hit the ignitor button...only see it about every other time i click it....anyways lemme know what u guys think!

enjoy!
moze304
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Joined: Sat Mar 22, 2008 9:19 am

Mon Mar 24, 2008 4:59 pm

also i forgot....if ur wondering how i got the shrader valve in there..it was a little tricky because plastick was too thick to get it to sit right...we had to countersink it.
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