Compressed Air BB Machine Gun
Comments (0) Tim and Houstin came by on Thursday and after playing with the cannon for a bit Tim asked me to see if I could make a compressed air vortex bb machine gun. Tim found a link to one at http://www.burntlatke.com/bb.html that I thought I could modify and make easier to build.
Note the following takes place in fits and starts over the last 2 days and some things are out of sequence of the way it actually went but I think the basic facts are here.
Took a piece of 3/4 inch diameter pvc pipe and cut a 1 inch piece. Chucked it up in the lathe and trued the ends and cut it down to about 3/4 inches long. Changed tools and cut a groove down the center. Ruining the first one by getting it off center. After cutting and truing another piece I got the groove cut.
Found a piece of tv antenna that was 1/4 inch inside diameter and cut it to length for the barrel. Side crack to be duct taped later in the build. Also got a piece of 1/8 id copper tube to use as the air inlet. This was a mistake and I corected it later with a piece of plastic tubing.
Drilled the appropriate holes for air and barrel and super glued the pieces into the proper positions after putting the vortex into a 1 inch pvc Tee.
Cut a valley the width of the vortex into the end of a 3/4 inch end cap that was glued on to a 4 inch piece of 3/4 inch pvc and cut it down so it fit into the bottom end of the Tee.
Drilled a hole in the end cap for the air inlet to go through and then used epoxie kneedable putty to hold the vortex in place in the grove of the end cap with the barrel sticking out the center of the Tee.
Cut a round piece of plastic, from a piece out of the inside of a refrigerator, to go around the barrel keep the the bb’s in the Tee and put it in the middle hole of the Tee.
Cut a piece of aluminum and made a cap to block the bb’s from filling the vortex and put it in place down the top hole of the Tee.
Cut another circle of plastic and then cut a hole in it for a 1/2 inch iron pipe closed nipple, and put it into a 1 inch coupling.
Cut the coupling off just on the other side of the center stop.
Machined the cut end flat and after drilling a hole for the 1/2 ip closed nipple in the top of a gator aid bottle I used two nuts to put the bottle top and coupling together. With the bottle in place this is the bb reservor and feed.
Cut a 1 inch piece of schedule 20 pvc and put the coupling/cap piece on the top of the Tee.
Cut another circle of plastic and drilled a hole the size of the barrel and with a piece of 1 inch pvc and another coupling made a cover for the barrel.
Replaced the copper pipe with a piece of hard plastic tubing from an ice maker.
With a valved air source hooked to it and the gater aid bottle filled with plastic bb’s this little sucker will spray a steady stream from 40 psi up.
Painted it last night. Still got to put a handle and valve on it but should have it done and working later today. And no I didn’t take pix. Will build another one soon and take pix then.
**Update – Took some pix of bits and pieces for those interested.
Themocracy