A new version of this gun, the semi and full auto Ingram MAC-10 RBG is now available, here. A simple mechanism explanation can be found here.
This is a HUGE gun with little performance. But it can shoot rubber bands, and there are 3 modes to choose from: locked, semi-auto and full-auto. The mode switch mech is #&*(%^#@ complicated and clumsy but works quite well. It is basically a rectangular case in place of the trigger's ratchet. In semi-auto, you pull the trigger and the rubber-band-pulled hand inside the case is free to rotate, but the case is pulled back so it stuck on the other side of it
only until you have released the trigger that the hand can complete one rotation, but then it got stuck again. switching to full-auto means turning the L-shaped ratchet that hold the hand after the trigger is pulled away so that it doesn't hold the hand back any more. lock mode means switching the position of the longer and the shorter part of the L-shaped ratchet so that the hand got stuck after one trigger pull and cannot complete a rotation after the trigger is released.
Well, as clear as onion soup, right? the gun doesn't worth copying, it's just a clumsy prototype, but if many people request, I'll take some pics of the mech while breaking the gun. Video also coming up!
nice view of the right side. Note the size of it!
the breech, with a hole for a crude sight not necessary
anyway, it's not very accurate.
rear view shows some of the mech inside. the rubber wheel is for easier turning when loading.
the source of all the big-ness the red hand is the mode switch. it moves with the trigger, hence the groove that i put my finger in.
locked and loaded.
the big boy can hold 15 medium size rubber band (the one on the right), slightly bigger than the one I used on my simple semi-auto rbg (on the left). actually, both can be used on either gun, but the medium sized bands give more range and less stress, so i preferred it. and it does hurt! not a lot, but it does! i shot my nosy sister sometimes when she spy around my workshop-bedroom and, honestly, i enjoyed it.
this is my cheeky 4-year-old brother in his Transformer mask pointing the gun at me. I took the photo just for the fun's sake of it.
PS: I'll be on vacation for some weeks. But stay tuned, a video of this gun in action and a sniper rifle coming up! and to Jongejansee (sorry if I spelled it wrong) I name my sawn-off shot gun for its performance, not its look (so you might want to change your rating :-D)
August 18th, 2008
to jamie hyne's question: no, it needs no motor. I used the battery box for the handle because I don't have enough time and pieces to build one out of brick.
August 22nd, 2008
this is the video of the gun in locked mode. look carefully and you can see, no, you can't see any rubber bands firing out. then, the gun is switched to semi- auto ...
the gun in semi-auto. sorry, i shot the vid by a cell phone so the quality is bad and duration is limited to 20 sec. the time limit made me decide to load three shots only.
and the gun in full-auto, more like buckshot mode actually... you can see that the gun jammed at the first attempt. i intended to shoot the video a second time to get it right but i wanted you to see it jam so i just pause the cam and resume after reloading the gun. this time i shot against a flowery background so that you can see the rubber band more easily.
I'm making a rbg with my new Mindstorms NXT set. gonna take long time and school is coming soon.