Instructables
This is a semi automatic Lego rubber band gun that can also be easily changed to auto.. but then with rubber band guns semi automatic is more of a challenge to build- here's how I built my trigger mechanism... this is my remake of it that contains step by step pictures i hoped could be comprehended.. contact me with questions of comments please! =)
see it in action here : http://www.youtube.com/v/-8ly4yEf0Io&hl

Step 1: The main ideology behind the mechanism

Picture of The main ideology behind the mechanism
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ok so basically the way this works is mostly all int he gears- I have it geared so that whenever a rubber band is released (only one) the "trigger wheel" (grey beam in the middle of the sideways v) spins only once. so in other words one rubber band=one trigger wheel spin. Then the "trigger" (purple bent beam) is connected to a sort of ratchet mechanism that when I pull the trigger back it makes the ratchet release the trigger wheel which the rubber bands put enough force on to release one. Also I have a rubber band connected to the trigger (the trigger is just connected directly to the "ratchet"or "v" (because it wouldn't fit on the inside of the trigger frame because the two gears that hold the bands are there). soryr this isn't more detailed but if you ahve any questions feel free to ask.

Step 2: Have fun!

Picture of Have fun!
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I think loading is pretty self explanatory to any one with any experience whatsoever with rubber band guns; but what you do to load it is stretch the rubber band from the end of the barrel to the gear then you can pull the trigger in order to push the gear back too and I've had success with loading as many as 12. here's a video of me shooting it in my closet =P.


 
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cam I use a little...engrenage?
Gamer9175 years ago
i have a full auto rifle thats amazing for lego wars (kinda like knex/nerf wars but with lego guns)
(note for future guns) ferret2992 first off you shouldnt leave the gun open or bable to c the rubber bands as when you are havig a war sum1mite hit the bands with 1 of theirs possibly letting the ammo fly off and getting shot repeated times at close range and with a powerfull gun (like my friends gun) so ya and if they are closed in they are less suceptible if they are enclosed and use a clip that holds bricks as shooting bricks is much more acurate(c my gun vid below if i can figure out how to post it) haha
http://www.youtube.com/watch?v=xVkBwiSxUxQ
ferret2992 (author) 6 years ago
umm ill try to get it up soon but hte pics are takin forever to upload =/ umm Im afraid it may not work with different gears.. maybe 2 shots at once but you need my gearing set up in order for it to work semi-auto.
try to upload them 1 at a time
if you can only make it move a minimum of like 3 notches just put rubber bands every third one.
alester275 years ago
i can't get it to work, and i can't understand the directions.
furferret6 years ago
lik wen r goin post the more detailed one; ru goin to be posting it a few days, weeks or wat! p.s. can you show it with different gears i have the big one but the 3 smaller ones, maybe the ones from a bionicle ?
furferret6 years ago
how do u load rubber bands !
ferret2992 (author)  furferret6 years ago
hold on im gonna upload a much more detailed one in a little while.
ferret2992 (author) 6 years ago
for everyone wanting more detaild instructions I think I'll edit this and make a more detailed set of instructions.. sorry it took me so long to get around too.
rafaipod6 years ago
hey where you get the v lego pice
ferret2992 (author)  rafaipod6 years ago
I believe from either lego mindstorms or from some random lego technic or lego designer set
and extend the barrel
wow you have no idea how long ive been trying to design a trigger mechanisim for my lego gun. i think im gonna use this. thanks
ferret2992 (author)  Gibson_SG_956 years ago
sweet, no problem.. glad to be of help =]
Maxaxle7 years ago
The pictures aren't very descriptive, can you post instructions?
hatae557 years ago
oo00oo im making a semiauto knex gun (thompson smg[body] + colt revolver[firing mechanism]) ill post when im done... Then ill be out of the unposting looseriness :)
hatae55 hatae557 years ago
the "body" and mechanism should of read (body) and (firing mechanism) but i used square brackets
hatae55 hatae557 years ago
it fires blue rods, not bands but is easily modded for bands
nibuoy7 years ago
can you explain how the trigger mechanism works? thanks just wondering
ferret2992 (author)  nibuoy7 years ago
ok so basically the way this works is mostly all int he gears- I have it geared so that whenever a rubber band is released (only one) the "trigger wheel" (grey beam in the middle of the sideways v) spins only once. so in other words one rubber band=one trigger wheel spin. Then the "trigger" (purple bent beam) is connected to a sort of ratchet mechanism that when I pull the trigger back it makes the ratchet release the trigger wheel which the rubber bands put enough force on to release one. Also I have a rubber band connected to the trigger (the trigger is just connected directly to the "ratchet"or "v" (because it wouldn't fit on the inside of the trigger frame because the two gears that hold the bands are there).
i've been making rubberband guns, but i can't make i semi auto. you have to reload after every shot. could you explain it a bit more clearly?
ferret2992 (author)  nibuoy7 years ago
yea, um alright I'll try.. so the big difference in this gun to other ones, is that this gun uses gears also to hold the rubber bands and I used a certain gear ratio so that when one rubberband is fired, a small shaft also spins around only once, and that's where the trigger is, it releases the shaft to spin freely but I put a small thing on the endf of the trigger that catchs the shaft so it only spins once and no more than once, this way one trigger pull = 1shot,
i've got it all down except for the trigger. the v shaped thing doesn't catch the grey beam and all the rubberbands are fired at once
it says the vid is unavailable
This is kind of off topic, but im trying to post my first instructable and im having trouble with the pictures. I was wondering if anyone else does
I have instructions for a semi automatic lego gun on youtube, this is the link: http://www.youtube.com/watch?v=8G_KFCrGt8k
ferret2992 (author)  koenigseggccr0077 years ago
it's the exact same gun as mine jsut better instructions.. good instructions..bad song.. haha
I know, I should have asked for your permission to post the gun on youtube. I'm srry! :)
ferret2992 (author)  koenigseggccr0077 years ago
aah that's ok man.. ncie job on instructions and a tiny bit mroe solid design =P a credit might be nice ;D haha.. good job tho.
that is done!
ferret2992 (author)  koenigseggccr0077 years ago
alright thanks =P =] haha nice modifications ;) I modified my version too..it can do single semi two shot or three shto burst, and full auto.
ferret2992 (author)  koenigseggccr0077 years ago
hmm looks familiar for some reason... oh yea! that's becuase you took the exact design of my gun and took all the credit for it! lolz...
zeero3607 years ago
yeah that would be good i u could take it apart and send the pics(could u send them to me 2?) sry bout da spellin from me
xegghead157 years ago
yayayayay some 1 found how to kind of make the lego gum gun
naurtomoe7 years ago
hey i was wondering if you could send me a pic showing all the pieces you need to build the gun..that would be really helpful...send it to samusblastertron92@gmail.com THANKS!
ferret2992 (author)  naurtomoe7 years ago
alright I'll get on that-I'll dissasemble it and send U the pics later
ItsTheHobbs7 years ago
somtime i gota put my basic lego gun design on, pretty much the same basic idea as k'nex gun, but with legos
ferret2992 (author)  ItsTheHobbs7 years ago
sounds kool... I'd love to see that soemtime =]
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