Introduction: K'nex AST Rifle

Picture of K'nex AST Rifle

Special Rifle Design Featuring Rapid-fire Capability

Type: Rifle(AST)
Weight: ~500 grams
Ammo Type: 13 centimeter Red Rod
Range: 10 meters
Firing Interval: 1 second
Mag Capacity: 17
Mag Reload Time: 20 seconds

Step 1: Gather Materials

- 20 White
- 31 Yellow
- 11 Green
- 6 Red
- 20 Orange
- 3 Light Grey
- 13 Grey

End Connectors
- 8 Brown

- 1 Grey
- 23 Red
- 10 Yellow
- 4 Blue
- 48 White
- 65 Green

- 1 rubber band (works best with one from head of broccoli)
- 3 doubled regular rubber bands. (Twist to "8" and down to double)

- Tape (clear)
- Paper

Step 2: Side Layer Template

Picture of Side Layer Template

This shows the side of the gun without the center layer, which is the next step. Do not start building this layer, but use this as a reference to attach pieces to the center layer.

You will need 2 of these for the sides of the rifle.

Step 3: Construct Center Layer

Picture of Construct Center Layer

Begin building this center layer. This is the lower portion of the gun barrel. If you plan on using this gun for a long time, you may want to cover the marked portion with 3 layers of clear tape. Over time, the firing pin will cut into the joints of the pieces. You may start putting down tape from the right side up to the yellow piece.

Step 4: Combined Layers Template

Picture of Combined Layers Template

This diagram shows the position of the three layers. Do not start building the layer from Step 2 yet.

Step 5: Combine Layers

Picture of Combine Layers

So you probably figured out why I suggested not building the side layers. Now you can easily attach the connectors from the side layers to the white rods.

Step 6: Construct Firing Pin and Trigger

Picture of Construct Firing Pin and Trigger

See notes for construction details.

Step 7: Complete Trigger - Top View

Picture of Complete Trigger - Top View

Top view of trigger once attached to frame. Note the brown hubcap connectors used to secure the ends of the blue rods.

Step 8: Construct Lower Trigger

Picture of Construct Lower Trigger

Once you have completed the upper portion, begin construction of the bottom of the trigger. Put a blue rod through the greys that are attached.

By now, the trigger should act like a hinge if correctly constructed. It should be able to move up and down, with the red connector stopping on the barrel but moving freely upward.

Step 9: Trigger Unit

Picture of Trigger Unit

Attach this unit to the blue rod space from previous step.

Step 10: Attach

Picture of Attach

Attach the unit built in Step 9 to the space on the blue rod in Step 8.

Step 11: Final Components

Picture of Final Components

Attach the rubber band, brown hub cap connectors in front of the magazine, and firing mode toggle. The toggle consists of an orange connector with blue rod. Grey and brown connectors attached to rod vertically.

Step 12: Use / Troubleshooting / Mods

Picture of Use / Troubleshooting / Mods

The grey and brown connector under the trigger serve as the firing mode toggle (must point down).
1. When both are pulled back, the trigger will not drop down. This is the rapid-fire mode, which allows the user to discharge the weapon repeatedly.
2. When both are pushed forward, the trigger is able to drop down once the firing pin is pulled back far enough. Once it drops, slowly release the firing pin. Now the weapon can be discharged any time by pulling the trigger. Do not suddenly release firing pin as it may damage the pieces.

1. When pulling back the firing pin, it abruptly stops/jams.
1. This is because the K'nex rods have grooves in them. When the bullet and firing pin are pulled in opposite directions, the grooves will cause it to jam. This can be fixed by taping the front of the firing pin. Ensure the tape is smooth.
If you are confused, take two rods, pull against each other and notice how they stop near the ends because the grooves stop.

2. The lowest orange connectors on the magazine are always breaking.
2. This is because when you pull the firing pin, you are pushing down to far. The firing pin is now crooked and upon release it hits the magazine instead of the bullet. This will only happen in rapid-fire mode.

3. The bullets aren't even making it out of the barrel! I hate you, faust, your gun is horrible!
3. You might have built the rifle incorrectly, or you are using weak rubber bands. Find the suggested rubber band or half twist 3 regulars to compensate. Attach regulars so they are taut before the pin is pulled. Also try the mods.

4. Rubber bands often break.
4. See rubber band suggestion in #3.

1.Fold paper and stuff it between the lowest orange connectors of the cartridge. Tape it up to secure. The firing pin will sometimes hit the connector and over time will cause it to break. This will prevent the orange connector ends from breaking.

2. Also tape the back region so the firing pin will not cut into the pieces. Notice the damage caused at the orange/green joint. Alternatively you can tape the entire length of the barrel.

3. Note the yellow connector of firing pin. Somehow smooth the back by paper stuffing or something so the rubber band will not be unevenly stressed when pulling back. Will lengthen life of rubber band.


crestind (author)2013-05-13

Good lord what a flimsy crap trigger I designed lol. Still one of the first K'nex guns on this site though...

crestind (author)2013-05-13

Kind of funny how the trigger prevents everyone from building this model LOL

~KnexBuild~ (author)2011-09-07

awesome pistol 4*

mahmel (author)2011-07-11

I don't see how it works.. for nearly 5 years now:)

wiishadow4 (author)2010-05-11

 i've been stuck on this step for about 2 hours now.

ahussain (author)wiishadow42011-05-14

this trigger doesn't quite act as a "trigger"

ryry2011 (author)2011-02-22

cool will you sub i sub

killersir751 (author)2010-10-28

im pretty sure its a good gun

thatgreasymechanicguy (author)2010-10-21


CuddlesMcT (author)2010-09-20

Somebody plays Armored Core :D

crestind (author)CuddlesMcT2010-09-21

Another AC fan :D As I'm sure you've noticed I was pretty obsessed with AC for a while lol

CuddlesMcT (author)crestind2010-09-21

Lol same! I have every single one but not the NEXT ones, or PP or MOA

crestind (author)CuddlesMcT2010-09-22

The only ones I'm missing are the PSX ones and AC Ninebreaker. ACLR was probably the best AC. The older ones are so hard to find now.

CuddlesMcT (author)crestind2010-09-22

I know right? LRs the only one i still play. To me Ninebreaker was like a variety of AC tests.

usb key (author)2010-07-09

you definetly need pictures and further explaination for the toggle deally.

brycerogers289 (author)2010-06-12

i can not figure out the trigger part

wertywaster (author)2010-06-09

Y did u put red rods for the bullet!

wiishadow4 (author)2010-05-11

 i've been stuck on this step for about 2 hours now...

wiishadow4 (author)wiishadow42010-05-11

 now 3 and a half, i am not lying.

crestind (author)wiishadow42010-05-12

 If you take pictures of what you have, I might be able to help you.

Pizzapie500 (author)2010-02-11

Sorry for late reply, but that link doesn't work anymore. Where would you buy this?

RMConstruction (author)2009-06-12

Who the hell in their right mind would buy this???????? IAC's spiff uses roughly the same parts, and is way powerful

knexguy (author)RMConstruction2009-08-06

This was up for sale before the Spiff ever appeared.

RMConstruction (author)knexguy2009-08-06

Whatever, i'm just saying. $30 ius way too high for a... well, let's just say... a gun like this.

DJ Radio (author)RMConstruction2009-08-06

Normally, you dont buy a knex set because of what you can make with it. You buy it because of what parts it has.

RMConstruction (author)DJ Radio2009-08-07

Agreed, but a 400 piece tub for $20 or £20 has a better overall parts list.

DJ Radio (author)RMConstruction2009-08-07

This gun probably uses more than 400 parts, and it also comes with no micro knex and no knex bricks!

Pizzapie500 (author)DJ Radio2010-02-11

Sorry for late reply, but this gun (including rubberbands) uses 267 parts, this would be good for about $20 because of no micro and what not. BUT this is used parts and $30 for 400 NEW parts is better than $30/$20 267 USED parts. I'm just saying, I got 30 pounds of USED knex for $20, and it had well over 3000 parts.

Bartboy (author)RMConstruction2009-08-08

No..... 20 quid for a 400 piece bucket would be a ripoff.

DJ Radio (author)knexguy2009-08-06


Seleziona (author)2009-12-09

gotta love Ol' Skool guns!

KnexFreek (author)2009-10-17

my gun that shoots red shoots alot farther and looks cooler 

crestind (author)KnexFreek2009-10-17

Congratulations! You've won a free internet!

KnexFreek (author)crestind2009-10-17

 sorry about my mean comment boasting my gun, i was just reading tons of great comments on yours and i have like 1 good comment on mine and i was impulsive and i wrote that

but... free internet? wtf?lol

crestind (author)KnexFreek2009-10-17

This gun was originally published in 2006, and was one of the original K'nex guns. That's partially why.

KnexFreek (author)crestind2009-10-17

oh well then i will change my rating to 4stars

~Z~ (author)2009-10-06

could u pls post a picture of the trigger sideways?

rosser (author)2009-08-29

where do the yellow things go dude?

rosser (author)2009-08-29

cool weopen I really liked it! : 0

An Villain (author)2009-08-27

magazine is not very strong, but that can be fixed.

Bartboy (author)2009-08-03

Not a good enough instructable. But the gun is quite cool, the trigger needs more pics, and you need to take close-ups of the finished gun. 4*

knexguy (author)Bartboy2009-08-06

You do realise this was one of the first ever K'nex guns, right? And I could build it 2 years ago.

Bartboy (author)knexguy2009-08-06

You do realize that I am talking about the quality of the pics, not the gun. Although, this gun isn't very good... So? Being 2 years old is no excuse for something not to work. A 2 year old computer doesn't get respect because it is 2 years old.

PieMaster777 (author)Bartboy2009-08-23

U Suck...

Bartboy (author)PieMaster7772009-08-24

No offense, but what do you know?

PieMaster777 (author)Bartboy2009-08-24

i know that the pics of guns u made are not creative or really that good, its easy to see you over exagerrated the distance that ur guns shoot. they lack a barrel, all they are are basic pistols wit long stocks, if you want to talk about power i made a small crossbow roughly 1/2' long that can hold two small taught bungee cords without even showing signs of bending let alone breaking, also it shoot completely through my wall and is very well thought out to be able to withstand such power wit its size, should i post it?

DJ Radio (author)PieMaster7772009-08-24

His specialty is not in knex guns.

Bartboy (author)PieMaster7772009-08-24

You only looked at my pistol....the point of a pistol is to be small.... But it is stronger than this gun. I build rifles. Over exagerated? How many feet long is a honda pilot? About 10 feet . My rifles all go at least 10 times the length of the car, and that's without sniper rods. Some can even break glass from 10 feet. Sure, why would I care if you posted? K'nex crossbow are (almost) all useless. The point of a bow is to use the power of the bow bending for power, but if you use bungee cords, you're cheating.....

PieMaster777 (author)Bartboy2009-08-24

the use of bungee cords is a resistance test, and ur thinking of a bow, an older one at that, modern crossbows and even bows use stretching stings and pulleys to generate an abundance of power. also, i looked at more than ur crappy pistol, i looked at ur rifles too, they are basic pistols, that have really long stocks. know what ur talkin about before u talk.

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