KPA-3 High Power Knex Gun

The KPA-3, or K'nex Projectile Accelerator 3 (Hey, I had to give it a cool name, right?) is my most recent k'nex gun, and my first to post on this site. Unlike the name suggests, this isn't my 3rd k'nex gun (i've been making k'nex things that shoot stuff since I was like 5), but it is my third in my KPA like of weapons. I built this gun focusing on raw power and accuracy, not aesthetics or rapid-fire. This gun IS powerful. Take a look a some of the damage shots on the last page. The thing that makes this more powerful than most rail-based k'nex guns is that the rail gap is slightly wider than the projectile, eliminating almost all friction. However, that would causes the projectile to slide around when aiming, but i fixed it so that doesn't happen. Since it's a rail-based k'nex gun, it's also very accurate (and it's probably even more accurate when you're not a horrible shot like me).

Gun Pro's:

-Very high Power
-Very high Accuracy
-Wide range of possible projectiles
-Ergonomic feel
-True-Trigger
-Sturdy
-Detachable Barrel
-Bipod (detachable, of course)

Gun Con's:

-Heavy
-Takes a good amount of pieces (especially green rods)
-Bipod connection can break if your not careful
-No Mag

This gun uses a simple mechanism, and i have found no flaws. I find I can cock and load the gun in about 8 seconds. The gun will easily penetrate several layers of cardboard, several cans, or drywall, and is best for close-range shots. I don't sharpen my rods, so i have no idea what this is capable of with a sharp point (please tell me if you try it :) ). I use latex rubber tubing to power my guns, which i got here, but you can probably find it at your local store. You can use rubber bands or elastic, but it won't be as powerful. This gun is not meant for a k'nex war. It should never be fired at any living thing.

If you like this gun, you'll probably love the KPA-4... after i get it designed and build. I'm already in the planning stages for it, so you can expect to see it probably a few months after i publish this.

Step 1 Trigger Assembly

This is by far the easiest step (I wanted to start you all off easy). This makes the trigger mechanism, which we will install in the gun body when we make it in the next step.

Directions follow. (#1 goes with picture #1, #2 goes with picture #2, etc.)

1. This is what you will be making in the following steps.
2. Make these three things.
3. Assemble like so.
4. Insert a white rod in the two gray connectors on the trigger, and snap the last remaining part in the center.

Your done (Yay).

Comments

[dragon#1]

do u know if the barrel being shorter will work?

[silentassasin21]

knex man go byby *sniff*sniff* he was my friend i dont like it when my knex friends die

[dragon#1]

haha nice makin friends i see no harsh feelings

[thomaswatton]

You should make a scope for this, maybe like a dragunov's where the scope mount is at the side so it doesnt block the bullet.

[Danielzxzx1]

Wow I'm going to make this but does anyone know how far it goes?

[FlutterTree]

Broke the 4 star barrier!

[MegaMetal8]

cool

[PineapplebobTheGreat]

finally, a good-looking sniper that doesn't use 30 y connectors haha. Nice job, 5 stars.

[cokeman]

what is the range

[Dr.Squirrel]

nice

[ashfall]

you must have SOOO many pieces in order to build that....... gj looks great too bad i cant build it XD

[chazman2]

(removed by author or community request)

[DJ Radio]

.

[smattman22]

i like the last pic! btw i might build this when i take apart my heavy cannon. it took up all my useful pieces haha

[Tom Buckey]

Whoa?!? where did you get those elastic bands? (picture two)

[jacobjordan]

http://www.amazon.com/Grafco-Pure-Amber-Latex-Tubing/dp/B000TVPK00/ref=sr_1_2?ie=UTF8&s=hpc&qid=1248054414&sr=8-2

[baseball508]

how far do u think this gun can shoot in range

[Tom Buckey]

Thanks

[blackandwhitejoker]

Argh! I only have one of the wheels at the end of the barrel what else can I use?

[baseball508]

no u cant i tried

[KnexMaster7000]

lol the bullet describings are kinda funny. well the first 2 are. i like the gun nice job :)

[anddre111]

i agree, i did not even half to make the gun to figure out that it wouldent be very new. And to add on that i dont see why you just make the barrel smaller nd increse the tension of the elastic bands, or if you cant find a band strong enough just add an ammount or bands insted, but over all i thing it is a *3.

[Oblivitus]

It's a good gun, but most of it has been done already, I was expecting something like this to come out when Oompa Loompa posted his Goliath MSG. The wheels do balance out the tension in the barrel so much more power can be added without the barrel breaking. The gun is basically a longer version of that with an SRv1-like design. Although it is a good gun, I can't understand why people are giving this a five star rating, it is simple and the mechanisms have been done before. I rate it 3.5.

[geodez]

actually he should post this because the goliath MSG and all oompa-loompa's other creations are gone.

[Oblivitus]

Yeah, I heard that recently, I don't understand why he would do that.

[geodez]

he says he wants to "clear up some clutter" to one person but to another he says he wants to "recede into the shadows" on instructables. i really do not understand it.

[DJ Radio]

What a Jerk, I wouldnt even care if the ibles were bad, but they are very good, so Im upset and mad at him.

[Oblivitus]

Someone should make a forum for posting any pictures that they have from his instructables to make a slideshow. That way, people will still be able to see his k'nex weapons. PS: When I say someone, I don't mean myself.

[DJ Radio]

yeah, we could make a slideshow. Call it Oompa loompa: Greatest hits.

[Oblivitus]

Yeah, and then we'll sell them to the masses and have concerts and put them on cd's, and, and, and! Lol, just kidding, someone should make a slideshow though.

[DJ Radio]

I think of the knex ibles as music on the hot 100 or something.

[Oblivitus]

Your not crazy or anything... lol.

[DJ Radio]

We should have a "top knex guns" list or something.

[Oblivitus]

Ratings determine the best guns, what more do you need?

[DJ Radio]

no they do not, we get hater attacks on ratings for no reasons.

[Oblivitus]

Yeah, you'll have to figure out a way to list all of the best guns though, it won't be easy unless it's completely your opinion and then the list will lose credibility. Maybe you could compile all of the k'nexperts opinions.

[DJ Radio]

ahh, forget it. My OSSR got a 4* rating 2 days since it was posted.

[geodez]

i know, he made us all mad.

[jacobjordan]

I wasn't looking to invent something new or complicated, just make the most powerful gun i could design. I made a couple rail-based knex guns off this site, and found the main limitation was the friction created by the barrel. Making the barrel wider than the projectile really eliminates almost all friction, increasing the power greatly. Adding on the wheels were actually something i did after i already built the gun, and at the time i honestly had never seen a knex gun with wheels on it before.

[DJ Radio]

Ima go ahead and use this for myself, is that allright with you?