Just read this, from the news section:

www.gazette.net/200150/aspenhill/news/83482-1.html

So now I'm wondering...

(1) What kind of ammo do you prefer in your gun and why... Idaho, russet, new potatoes, etc?

(2) How about sights?  I personally take the cup from a biggie coke, cut the end off, and duct take it to the end of the barrel, then duct tape a potato masher to the other end.  Can you think of a better configuration?

(3) Anybody got any good recipes for used potato gun targets?

as for ammo:

When I built mine, I took the end of the barrel to a grinder to give it a sharp edge.  Then you just push a potato onto it and ram it home with a broom handle.  This seems to give the best seal.

I had one cannon that would perfectly fit a golfball down the tube.  Now, those things were fun to shoot!

Green tip Potato for me.  (with the steel penetrator) works good with a 1/7 twist.

I don't know...but, White Rain is the best propellant. It still has the ultra flammable Floura-carbon gas. I bought a bunch of cans a couple of years ago at Dollar store.

Sounds like a M-80 going off...for extra fun, soak your potatoes in Gasoline!

Just kidding!

I did like Brouha did...and sharpened the edges of the opening so the potato excess will be cut-off.

I've put sweet potatoes...tennis balls...nerf balls. I did stuff some White Rain soaked paper in it....just to get a pyro-technic effect. WHOOOOOSSSSSSSHHH!!!! Danger,danger...warning. Dumass ahead! Just don't do it!

Boom, boom!
NAKED

Another fun projectile I have done many times is an ice shot.  I take a scrap piece of PVC, the same as the barrel.  Put plastic wrap on the bottom, coat the inside with Vaseline and fill it with about 2 inches of water.  Let it freeze, pull it out of the freezer push the ice out of the mold, drop it in the barrel and BOOM! Shoot a tree and it compacts the ice onto the bark, and rains down pellets of ice for a couple seconds.  

Anyone have any plans for making one?
Length of tube, etc.?

Thanks

I'm gonna go to my storage unit and get the gun to give specifics..but, I think you get a 12" piece of 3" schedule 40 pvc w/ threaded ends? Reduction adapter "threaded", to about 2 ft. piece of 2 1/2" schedule 40 pvc. Pvc glue the 2 1/2" & 3" together. Have the adapter on one end and a screw in (plug) on the other.

Go to Sears or Ace hardware and get an electric sparker/striker for a gas grill. They usually have these as replacements for gas grilles...I screwed 2, 1 1/2"  screws into the lower 3" piece of pvc attached to the striker and through trial and error...got the proper distance for spark. You'll have to get a mental picture after you buy the striker...where to place the clicker onto the pvc...etc.

I made a handle that I attached in order to have a "handgrip" of a sort,to make it easier to hold and aim. I attached the "clicker" striker onto the handle. Like a gun with a trigger. Connect the wires to the screws and make sure you get a good spark after you "click" the clicker.

Shove the potato into the 2 1/2" piece then unscrew the cap of the 3" and spray you hair spray propellant into the chamber...screw it back on quickly..BUT, DO NOT OVER-TIGHTEN! It will be next to impossible to remove if it is tightened too much.

I think you have about up to 2 mintues before the propellant becomes a liquid again...it needs to be gaseous for it to ignite.

Others can probably do better at explaining...sorry, I'm trying to relate something that I made without a pattern or prot-type  to mock from.

Hope it helps,
NAKED

You might try right guard.  I found the black can type to be a little less sticky inside the chamber than the hair spray.  I used 4" reduced to 2" for the barrel.  Works like a champ...  Anyone fired one after it has sat for several years?  I probably have not fired it in 5 years but have been itching to take it out again.  

Ammo, try a 1/4 full tube of caulking.  Great ballistics.......

Hey you may  want to put some screws in there to i had one come apart. Barrel smaked me upside the head loosened my teeth, Then also left one heluva bruse on my leg from the base of the cannon Damn it hurt. Now i use 1.5" Drywall screws and heat them up then screw them into the joints for extra safty. Oh Yes Don,t forget These are a firearm. just ask the local cops. Long story. Also i found that a colman  lantern lighter works longer and is way cheaper then the barbecue starter. plus lots safer.  

the best perpelent is aqua net in the blue can!!!

Round here we use oranges.

Potato Gun plans at:

    http://www2.csn.net/~bsimon/pngun.htm

aqua net is awesome..i think we made 1 with a 18" long 4" dia. chamber & a 4 foot barrel. i shot a half of a corn cob through a garage door from about 20yds.

Potato Guns Rock!  There is nothing like the sound of that thing launching a potato a couple hundred yards!   THWOOOOOMP!

Best propellent from my experience would be MAPP gas.  You can use a self-igniting torch for a combination fueler and ignitor if you are crafty.  You need a reed valve to allow air into the torch body but still provide a good seal.  

Quoted: Hey you may  want to put some screws in there to i had one come apart.

I screwed mine together after the barrel blew off and the flame licked my arms.  It burned all the hair off both of my arms.  Not to mention I had to scale the fence to find the barrel.  

It kinda happened like this.  "Look mom, we've shot these before, and they're perfectly safe!"  BOOM!  "My arm!  My arm!"  Followed closely by running around in circles putting the flames on my arms out.  No real damage, but I learned that PVC glue doesn't work real well.

Also, I learned never to shoot the thing by holding it between your legs.  One time the screw on cap shattered, sending sharp pieces of PVC everywhere.  Thankfully, I was holding the gun just low enough that it missed my boys.  Of course, there were a bunch of cute girls watching at the time, so we were a little embarrassed.

Whatever anyone here does, DO NOT SHOOT IT AT A PERSON!  We shot a potato at a 2x4 once, and the board shattered.  These things are definitely not toys.

Hairsprays are messy. Try WD-40, it works better and is a lot cleaner.

sorry guys but straight propane is the best.
frozen cucumbers will double over a steel trashcan.

Quoted: sorry guys but straight propane is the best. frozen cucumbers will double over a steel trashcan.

Propane works on the heavier projectiles but I found MAPP is the king for lightweights and screaming velocity out of short-barrels.  Never tried frozen projectiles.  

I liked using steel pipe, we used starting fluid and carrots.  good penetration on ply wood, hell on barrels and fittings.  real neat at nite.  use ear plugs.  sucks trying to load.

i just use hair spay and a lighter

I use a fiberglass wrapped section of PVC ( 4 inches in diameter, 1.5 feet long) as my air chamber with the solenoid from a sprinkler system as an airchambe, on the end their is file valve. On the other end I have a three foot length of aluminium pipe for a barrle. I can send a 'sabot round' ( A carrot sticking out the end of a potato) through quarter inch plywood at 35 yards when I charge up to 300 psi.

I use a 4"cahmber about 8"in lenghth then a reducer to 2" with a bushing to got to 1.5" then a clean out for the rear with a screw in cap.
For the ignitor try to find one of those flint lantern lighter they seem to work the best and epoxy them in with jb weld.or you can use those bb push button things but in my opinion they dont work as goo.
For a prpellent i use starting fluid all you need is a very small mist if you see moisture from it you've used to much and will not ignite.to little no power experiment.I to also grind the tip to an angle it does a great job peeling pototoes

Anyone have pics of theirs?  If I had a digital camera, I'd post mine!

I saw a show on the discovery channel once many years ago called "The Secret Life Of Machines".  On one episode the two English hosts built a potato mortar out of 4" steel pipe with a welded on base and angle adjusting framework.  If I remember correctly they had two ignition sources, the bottom of the mortar tube had a threaded bung welded in that accepted a shotgun primer with firing attachment or, get this, a spark plug.  The experiment was to show how much potential energy is stored in gasoline.  First the dropped about a tablespoon full of blackpowder down this thing and used the shotgun primer to launch a full can of green beans about 150 yards.  Next they switched to 1 tablespoon full of gasoline and the spark plug apparatus and proceded to launch the can of green beans to Jupiter.  In reality I think they finally found the can about 1000 yards away and smashed all to hell!  Wouldn't this be fun mounted on a M2 pintle in the back of your F150?  Woo Hoo