Make:

• DIY Halloween - The Classics :: Fog Chiller
• BUG on Arduino action
• NoiseBridge: new SF hacker space
• Pedal powered tank
• BASE jumping with accelerometers
• Self-disinfecting toilet brush

as much as i think these things are awesome, they can have a hefty price, far beyond $25.

my brother built a potatoe cannon similar to this one and the police charged him with felony arson and felony weapons manufacturing. each count carries a 2-year minimum sentencing... seems stupid, but that doesn't negate that it happened.

Unless he was shooting flaming tennis balls it looks like if sucks that you live in one of the municipalities where it is illegal...

However they is not illegal every where.
http://www.atf.gov/firearms/faq/nobackfaq2.htm

(A29) Are "potato guns" or "spud guns" legal?

"Potato guns" or "spud guns" generally consist of sections of PVC plastic tubing and fittings and are designed to launch a muzzle-loaded potato (or other similar-size projectile) using hair spray or other aerosol vapor as a propellant. The propellant is ignited by means of a barbecue grill igniter or other similar ignition system.

Section 5845(f), Title 26, United States Code, regulates certain weapons as "destructive devices" which are subject to the registration and tax provisions of the National Firearms Act (NFA). Section 5845(f)(2) includes within the definition of "destructive device" any type of weapon which will or may be readily converted to expel a projectile by the action of an explosive or other propellant, the barrel of which has a bore of more than one-half inch in diameter. However, section 5845(f)(3) excludes from the definition of "destructive device" any device which is neither designed or redesigned for use as a weapon and any device, although originally designed for use as a weapon, which is redesigned for use as a signaling, pyrotechnic, line throwing, safety, or similar device. The definition of "destructive device" in the Gun Control Act (GCA), 18 U.S.C. Chapter 44, is identical to that in the NFA.

ATF has previously examined "potato guns" or "spud guns" as described above and has generally determined that such devices using potatoes as projectiles and used solely for recreational purposes are not weapons and do not meet the definition of "firearm" or "destructive device" in either the NFA or GCA. However, ATF has classified such devices as "firearms" and "destructive devices" if their design, construction, ammunition, actual use, or intended use indicate that they are weapons. For example, ATF has classified such devices as "firearms" and "destructive devices" if they are designed and used to expel flaming tennis balls.

Possession and use of "potato guns" or "spud guns" may be restricted under State laws and local ordinances. Further, any person intending to make, use, or transfer any such device must be aware that they have a potential for causing serious injury or damage.

http://www.flickr.com/photos/91107493@N00/tags/potatogun/

This is my potato gun after I refurbished it. Very similar to what Make has posted, but cost me about $30. A future improvement will be the development of reusable and standardized ammo and of putting a grate at the base of the barrel but above the combustion chamber to prevent the taters from fallin in while you load.

Yes, that's right, I said taters.

Subscribe today, save 42% and get web access to MAKE free. MAKE Digital Edition is available only to subscribers.

$34.95 / 1 year
(4 Quarterly Issues)

Subscribe now