Pumpkin Pounder
Took the family to the local corn maze. It’s run by Oake’s Farm and is generally a good time. We saw the awesomeness that is the pumpkin pounder:
My kids asked me what it is and I told them. It’s a large air canister that they load with a pumpkin. Then, they shoot it. Like a potato gun. So, now the kids want me to make them potato guns so if you’ve got any particularly awesome plans for one, let me know.
Anyway, they shoot it. At a van. And it does a lot of damage to the van:
Here’s video of it in action:
I think our potato guns will be slightly disappointing.
October 21st, 2013 at 9:42 pm
http://billllsidlemind.blogspot.com/
Check that guy out, he knows of airguns. Send him an inquiry, he seems like a pretty straight up sort.
http://billllsidlemind.blogspot.com/2009/03/pumpkin-cannons.html
October 21st, 2013 at 10:05 pm
4 ft of 1 1/2″ or 2″ PVC, 4″ pvc and necesary adapters to fit it together. 4″ piece can be ~24″. Put a washout plug on the end. Get a piezo BBQ grill ignitor, use part of the mount, modified to put the button outside, you can use 2 screws coming in to the pipe towards each other w/ 1/4″ gap or the ignitor portion mounted inside using the same screws holding the button to outside. Grind a bevel on muzzle end.
Aqua Net hairspray works well for propellant. email me for more details if you need them.
October 21st, 2013 at 11:10 pm
Spud guns are NEVER disappointing, at least as long as they work. A couple additional notes to Nate from Ogden’s post: If you put the spark studs at 90 degrees, rather than 180, you can bend them a little bit to tune the spark gap. Also, if you use 1 1/2″ pipe rather than 2″, you can use milk jug lids as shotgun wads. I always put a threaded coupler at the breech end of the barrel, for ease of removal of a stuck potato and to make it a takedown to store away better. WD40 doesn’t work anymore, they changed it to CO2 propellant. I use a standard propane bottle torch (like a plumbing torch). It doesn’t leave residue like aquanet.
October 21st, 2013 at 11:30 pm
http://www.xinventions.com/main/spud/pac6.htm Here’s a link to place selling plans for a semi-auto potato cannon (although it works best with custom built PVC projectiles, if you’re after performance). He has a bunch of other plans as well, for various types (including a few breechloading spud guns). Otherwise the Backyard Ballistics book has some great stuff for spud guns, tennis ball mortars, and all sorts of other fun things. I’d provide a link for that, but it’d be massive and ugly, so it’s easier to just look it up (comes right up in search results).
October 22nd, 2013 at 12:35 am
Don’t use screws. Screws suck. Carefully bore and tap a hole center top of your combustion chamber and use a spark plug. Go slightly undersize for a tight fit. Take a plug wire down to the grill piezo. return a small 18ga or so ground wire, gap plug .065 in. and have fun. Also use propane instead of stinking hairspray – much cleaner, and less problems.
Also, these barrels are awesome.
http://www.spudtech.com/detail.asp?id=34
October 22nd, 2013 at 6:31 am
Is that a hearse in the background? I’m guessing in case of an accidental discharge of the pumpkin pounder?
October 22nd, 2013 at 10:34 am
Potato guns are great. But what about tennis ball mortars?
Start with a metal tennis ball can. Place a dent about 2″ from the bottom, sufficient to prevent a ball from reaching the bottom of the can. Use a nail to make a pin hole near the base of the can.
Stand the can up in a clear area, add a teaspoon or so of suitable liquid propellant. Please note this is not a tablespoon. It is vapor that supplies the power. Excess liquid actually inhibits good combustion and leaves a flaming mess that cooks the tube. Less is better and it may not work at all on a cold day.
Drop the ball in then use a long match or grill starter to apply a flame to the pinhole. This is best done from a prone position.
I’ve seen these things launch a tennis ball higher than ten stories from a condo parking lot.
Note: If you are truly irresponsible rather than pouring propellant into the base of the can you simply dip the bottom half of a tennis ball into the propellant, drop it in the mortar, then apply ignition as before. If, that is, you don’t mind sending an unguided flaming projectile a hundred or so feet in the air.
Not that I ever did anything like that. Especially not at night.
October 22nd, 2013 at 10:49 am
Cap one end of a four foot length of 2″ or there PVC pipe. Or don’t cap it. Drill a 1/8″ touchhole in what would be the chamber area. Rest it on the ground at about a 45 degree angle away from anything you like such as your face. If you haven’t capped it, use soft ground and dig it in a little. Spray in some hairspray — yup Aqua Net is great. Drop in something not too hard and not too heavy that more or less fits the pipe. Potato sounds good. Touch it off with the flame of a butane grill lighter up against the touchhole.
October 22nd, 2013 at 4:36 pm
Here in TX, such devices are legal only as percussive noisemakers; as far as I understand they count as AOWs if you shoot anything out of them.
Which is why the ones I made for my kids never got used anywhere near my neighborhood, except on New Year’s, for making loud noises and gouts of flame. What the kids did with ’em in the woods is anyone’s guess.
October 22nd, 2013 at 5:07 pm
The ones I built were similar to Nate’s and the boys thought they were very successful. Mine used Coleman lantern igniters though. They even got to use a variation of the Crocodile Dundee line when another kid brought over a spud gun about 2 feet long with 1 inch barrel. The range on these things is very impressive so be careful who’s house they are pointed at.
Later I built one with a tire valve and a ball valve for a trigger. Using an air compressor to charge it was slower than hairspray, but the spud would fly. Also tried using dog food with paper towel wadding for an antipersonnel shotgun.
October 22nd, 2013 at 5:39 pm
It would be interesting seeing one made with steam power.
October 22nd, 2013 at 6:51 pm
Just hydrogen and oxygen as your combustion mix. Instant hot steam 😉
October 22nd, 2013 at 7:32 pm
The only time I ever had a firearm pointed at me was a result of using beer can hand cannons to rid the backyard of fallen pears with my brothers. We were launching them down the alley, the neighbot lady thought we were throwing the pears into the air and shoting them with a shotgun- in town. Her call brought every police officer on duty with their guns drawn to our driveway and alley.
They told me I couldn’t do that any more…
October 22nd, 2013 at 9:45 pm
Were I to build a spud gun again, I would go pneumatic, as opposed to using hairspray, butane, or whatever. Air tank, sprinkler valve, barrel. There are a couple ways to do this. Returning to Billll’s place, Pedal Gun Fun shows the sprinkler valve tripped by a 12V source. There’s a way to do the pneumatic valve using only differential pressure, no electricity needed, but I can’t find the site where I found that. Might be I can track down an old co-worker and find it.
October 23rd, 2013 at 5:07 pm
Yes, there is a way to build a coaxial cannon with a valve that works on differential pressure. I have some CAD models that could be converted to jpg’s for easy viewing.
Drawback: They are a bit fussy in PVC. Ours at one point pushed the piston back and knocked the back end off the gun. Properly assembled, they are impossible to disassemble and repair. Other than that, they are impressively efficient.
The larger pumpkin cannon on my site will toss a 12 lb bowling ball about 1/2 mile. The pedal air gun will toss a weighted empty caulk tube about 130 yards or a weighted 12 ga hull 175 yards. I guess the question is how big is your back yard?
Give the kids one or two caulk tubes and a cardboard box out at the 100 yard mark and they will take turns shooting it all day long.
October 23rd, 2013 at 8:41 pm
I did find a page describing the piston valve. Not the site I was looking for, but same concept. Still trying the former co-worker route.