Page 2 of 4

Posted: Tue Jul 31, 2007 10:38 am
by BigFootWitness
should this chicken have a tight fit in the barrel or should it be a little loose?

Posted: Tue Jul 31, 2007 10:42 am
by jackssmirkingrevenge
Ideally it should be a loose fit in the barrel, then surround it with a wad of newspapers or similar to support it and seal the space behind it.

Posted: Tue Jul 31, 2007 11:33 am
by mopherman
BigFootWitness wrote:should this chicken have a tight fit in the barrel or should it be a little loose?
well if it is tight then you should *yuck* lube up that chicken. :?

EDIT! if you havnt already chosen a valve, i would go with a giant burst disk.

Posted: Tue Jul 31, 2007 12:14 pm
by DYI
4" diameter union with a burst disk would be pretty entertaining...
But the union alone would cost you 3/4 of your budget.

If you have an air compressor, a pneumatic design would probably be the way to go, if not, combustion would be better, as pressurising a chamber of the size necessary to project a rubber chicken 100 yards with a bike pump would get old really fast.

Also, I don't know if you will be able to achieve your performance goals with the set budget. Pipe and fittings of any material in sizes over 4" are really expensive.

Posted: Tue Jul 31, 2007 12:17 pm
by jackssmirkingrevenge
I'd agree that combustions are ideal for large calibre projects with a limited budget that need to be simply constructed.

Posted: Tue Jul 31, 2007 12:27 pm
by noname
Personally, I'd go with a 6" barrel and some wadding around the chicken.
Then you need some huge chamber though. I can give you some 8" PVC for a couple bucks a foot, but I'm not paying shipping.

Posted: Tue Jul 31, 2007 2:14 pm
by BigFootWitness
what would be better wading around the chicken, a foam casing made into a shell or should i just somehow fit the chicken in the barrel by fit him in tightly by using a smaller barrel? or exact fit?

Posted: Tue Jul 31, 2007 2:41 pm
by BigJon
Why do you want to shoot rubber chickens anyway?

I don't know if this helps but I saw some people using them with water ballon launchers once. But I'm not sure you would get 100 yards with one.

Posted: Tue Jul 31, 2007 3:01 pm
by BigFootWitness
So what do you guys believe I need to buy to construct this? Please list everything needed for the project.

Thank you!

Posted: Tue Jul 31, 2007 4:52 pm
by origin unknown
Get a mauler and then have a 4" barrel for a tight fit so when the lubed chicken comes out it will squeak because it will expand.

Posted: Tue Jul 31, 2007 5:12 pm
by turbohacker
Build something like this...

Posted: Wed Aug 01, 2007 9:05 am
by BigFootWitness
I'm fine with pushing a button. So Can somebody list what is needed to build this?

Thank you!

Posted: Wed Aug 01, 2007 10:36 am
by SpudBlaster15
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras nec placerat erat. Vivamus dapibus egestas nunc, at eleifend neque. Suspendisse potenti. Sed dictum lacus eu nisl pretium vehicula. Ut faucibus hendrerit nisi. Integer ultricies orci eu ultrices malesuada. Fusce id mauris risus. Suspendisse finibus ligula et nisl rutrum efficitur. Vestibulum posuere erat pellentesque ornare venenatis. Integer commodo fermentum tortor in pharetra. Proin scelerisque consectetur posuere. Vestibulum molestie augue ac nibh feugiat scelerisque. Sed aliquet a nunc in mattis.

Posted: Wed Aug 01, 2007 11:01 am
by Gepard
Reminds me of that guy that wanted to build a cannon for his pirate ship....

Michael

Posted: Wed Aug 01, 2007 11:08 am
by jimmy101
Very simple gun specifically for the rubber chicken. Use the same pipe for the chamber and the barrel. This works pretty well for large bore guns.

Take a plastic disposable cup (clear or colored plastic, not the Styrofoam kind) down to the local hardware store.

The cup won't fit very far into 2" PVC pipe (if it'll fit at all). So, try 3" pipe. Does the cup fit most of the way into the barrel? If it goes all the way in does it fit reasonably snuggly? If yes you have your barrel + chamber. A 10' length of 3" pipe is about $8. (The PVC pipe should have a pressure rating on it, something like 220 PSIG.)

Get a cleanout adaptor that fits the 3" (or whatever) pipe. One end of this fitting will slide over the end of the pipe. The other end has female threads. Probably cost $2.

Find the matching male-thread plug for the cleanout adaptor. Probably ~$1.

Get a pack of PVC primer and glue (one small can of each package together as a single item, $4).

Locate a piezo sparker. Most hardware stores have'm near the BBQ's. Probably $12 or so. (or try to salvage one from an old BBQ or lighter that has a piezo igniter)

A fan is not required but the performance of the gun will be much better with a fan. So, get a 40mm to 100mm brushless computer fan (5V to 12V). $3 from electronics surplus places, probably $10 from RadioShack. (Or rip the CPU fan out of an old computer). Get a 9v battery and battery clip to run the fan.

Cut the pipe to length. 3' total will work but be fairly low power. 6' should work well with reasonable power.

Follow the instructions with the PVC cleaner and glue to clean and glue the cleanout adaptor to the pipe. Let dry overnight at least.

Screw two screws into the chamber so that they almost touch near the center line of the chamber. I would put the spark about 1/4 of the way from the breech end to the muzzle end of the gun. Use some wire to hook the piezo up to the screws.

Figure out a way to mount the fan in the chamber.

Get a can of Axe (or other spray that uses propane and/or butane as propellant but doesn't include a lot of other crap like paint). Better yet, use a Benzomatic propane torch or a disposable butane lighter.

(A)
Take a disposable plastic cup (the clear plastic kind, not the Styrofoam kind) and push it into the barrel till it stops. Use a razor or sharp knife to cutoff whatever doesn't fit in the barrel. The part that fits in the barrel is your sabot.

Take the sabot out and flip it over so the open end of the cup points towards the chamber. Use a stick to push the cup halfway down the barrel. This gives a 1:1 C:B ratio which is fine. Drop rubber chicken in barrel. (If needed you can take another plastic cup and cut it like the first one then insert into the barrel open end towards the muzzle, this is a great way to fire water balloons and other small fragile objects.) If the cup won't stay in place you can screw a 1" or 2" screw into the pipe at the proper place to make a stop to catch the cup.

Squirt fuel into the chamber then screw on the cleanout plug. Run the chamber fan for a few seconds.

Point down range and push the Piezo's button.

Retrieve the chicken and repeat from (A).