Red Impact - Perfect Duck's K'nex gun. by Perfect Duck
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Mid-size, light-weight, sturdy and easy-to-use repeater. I can fire five red rods in a 10-second video. Holds 18.

It fires via weighted impact (typical) and features recoil dampening and minimal-friction loading systems not seen elsewhere. My entrant to any applicable K'nex gun contests.

A few exotic parts were used, firstly a metal spring that fits around a K'nex rod. Also, to make this, you will need to mutilate three dark grey connectors by cutting off their tops (remove half of the circle). Though you could get the spring at any hardware store, you can use rubber bands in its place.
 
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Step 1: -back end- The pile driving shaft.

Essentially, you're just building a sturdy hole through which the firing force of the gun passes through. It doesn't have to be exactly like mine, but what is shown optimizes on strengh and keeping out of the rubber bands' way. If you are a diehard fan of the orange connector type blocking trigger like in KILLERK's, go ahead and incorporate one near the bright-red connectors. I prefer pull-release, it's faster.

On the SPRING - it is extremely effective to use one here. You can get springs like these that wrap around K'nex rods at hardware stores (best bet) or from hobby stores (remote control cars) This is how the power is converted.

GREY ROD + ORANGE CONNECTOR -> BLUE ROD -> RED ROD (Projectile)
(Several rubber bands) (spring-loaded)

Let's save adding the grey rod for last.

Because the blue and red rods together still have less total mass than the grey rod hitting them, their velocity will match whatever speed you can get the grey rod to reach, assuming the laws of physics and transferrence of energy. The spring acts as a shock absorber, preventing any extreme stresses on the K'nex parts and returning to optimal position again.

Yours may need to be tuned differently from mine to keep the blue rod in the perfect place, but you'll understand this better once it's complete.

If you don't want to use a spring, rubber bands (fourth picture) are an alternative, although I've so far not had much luck with them. Loss of strengh.
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bboy321321 says: Dec 14, 2012. 3:13 PM
looks cool i'm going to build it.
Capt. Fat says: May 20, 2010. 1:58 PM

lol, this looks almost like the BFG from Doom! all u need now are some knex demons.....

ultimut cat says: Jun 20, 2012. 5:58 PM
ponyz!!!!!!!!!!!!!!111
SpeedStrikerXLR says: Sep 28, 2010. 4:59 PM
lol you are right! BFG9000
James368 says: Jun 8, 2011. 8:39 AM
do you have to use a spring
biky69 says: Apr 21, 2011. 12:09 PM
do you have to have the spring???
awaite says: Jan 3, 2009. 10:54 PM
How far do these knex guns shoot they dont look like they can do much
benfoxg says: Feb 25, 2009. 7:24 PM
they can fire over 1000 feet... with rocket engines glued to the rod. or about 500 without pyromaniacness. (hey I made a new word)
Perfect Duck (author) says: Feb 25, 2009. 9:00 PM
I wouldn't say they can go 500 feet. Just based on the density of a plastic rod versus the density of the fluid air that it has to push, that's just not going to happen, especially when rods begin to fly sideways after a short while (unless they are fin-stabilized, which guns like the Red Impact are unable to fire, also it brings up the issue of modifying pieces)

Also, the word you're looking for does exist, and is properly spelled Pyromania.
DJ Radio says: May 3, 2010. 1:26 PM
Slingshots like the SRv2 fire fin rods without modded parts.
thebookworm127 says: Jun 4, 2009. 12:24 PM
dude you should get a life, stop drinking soda and you know maybe play a sport or two
Fred the evil puppet says: Nov 26, 2011. 11:02 AM
we do what we want to do. i hate sport personally, and im sure DJ and perfect duck and most other epic knexers have hobbies other than sport.
soda is just carbonated water with E-numbers and flavourings, so i cant argue. but it still tastes good!
NYPA says: Dec 22, 2009. 5:54 PM
...


F9TV045FZWXOL5W.MEDIUM.jpg
thebookworm127 says: Oct 8, 2009. 9:33 AM
take the advice
Perfect Duck (author) says: Jun 4, 2009. 1:10 PM
I think you have this confused for a forum about personal matters. You're looking at a K'nex gun I designed 2 years ago, keep your comments relevant.
geodez says: May 18, 2009. 4:24 PM
if fired in zero gravity and a vaccum that extends infinitely they will go on forever or at least until they hit something
Fred the evil puppet says: Nov 26, 2011. 11:00 AM
...or is pulled into another planets field of gravity. (orbit)
geodez says: Nov 26, 2011. 6:13 PM
Yes.
xadevox says: Aug 3, 2009. 3:47 PM
lol like SPACE!?
geodez says: Aug 3, 2009. 4:31 PM
yes, but with no planets, stars, asteroids, etc.
benfoxg says: Feb 26, 2009. 6:57 AM
u sma. but I can still glue rocket engines to them.
J Moneyman says: Mar 13, 2009. 8:23 AM
he's right PD
J Moneyman says: Mar 13, 2009. 9:02 AM
that PD is supposed to be perfect duck, not a smiling one eyed pirate!
adio says: Feb 14, 2009. 1:43 PM
i built this before and i got like over 100 feet with 3 rubber bands
LordSnipe says: Feb 3, 2009. 1:28 PM
your normal k'nex gun (bolt action like this one) tops out at 30' in my experience. I have seen 100' ranges claimed, but have been unable to replicate the feat. If you want some real power, check out the sr-v1 or my LSSv1, both use a LOT of pieces, but in exchange you get some major (200'+) firepower.
geodez says: May 18, 2009. 4:26 PM
the R.P.G. by knex artillery can fire a very high distance and only uses a fraction of pieces used in the lssv1 or the sr-v1 or sr-v2
Wafflicious says: Jan 18, 2009. 3:44 PM
some can fire more than 200 feet but most about 20-100ft. (some can very much harm things)
knexjay says: Sep 16, 2009. 12:25 PM
muist u have spring?
Perfect Duck (author) says: Sep 17, 2009. 4:41 PM
The answer is in the instructable. -_-
ooglie_booglie says: Jul 12, 2009. 3:30 AM
i dont have any black rods (pic + 3 on the sides) can i use normal grey
DJ Radio says: Jul 18, 2009. 7:58 PM
yes, but it wont be able to support as many bands.
ooglie_booglie says: Jul 12, 2009. 7:19 AM
complexity you like that word dont you..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... ME TOO ITS MY NEW FAVORITE WORD HI 5
ooglie_booglie says: Jul 12, 2009. 3:58 AM
any replacements for black hinge pieces i only have 1
ooglie_booglie says: Jul 12, 2009. 3:18 AM
dispicable mistake lol
calvyn says: Jul 17, 2007. 6:50 AM
you could just a spring from a "clicker" style pen @_@
ooglie_booglie says: Jul 12, 2009. 1:55 AM
too small
ropple07 says: Apr 12, 2007. 1:57 PM
do you need the spring
ooglie_booglie says: Jul 12, 2009. 1:54 AM
on the last pic it shows the rubberband varriation of the gun
calvyn says: Jul 17, 2007. 7:18 AM
i used a pen spring. i unfurled the tighly coiled bit at either end by getting the blade of some scissors into the less dense bit and going round till i got the end with just the sharp bit on the end. then if you pull and twist against the diretion of the turn it gets bigger and looser. do this for both sides and then youcan force it onto a pencil (which is almost the same size of a K-nex rod) and force it on (carfeful with pointy end i stabbed my self and was bleeding a lot0 then you can take it off and put on the blue rod. only took 15 minutes and some blood
RMConstruction says: Nov 9, 2008. 3:32 AM
Lol, i did too. But i got 2 mins and no blood... im careful you see lol
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