Introduction: K'nex E.U. Tank

Picture of K'nex E.U. Tank

This is the_burrito_master's k'nex tank, based on the E.U. tank in Battlefield 2142. He built it originally, and I simply copied it from pictures and then made an instructable using Google Sketchup. Imperar created the individual k'nex pieces in sketchup. I simply put them together. You can find the 3d model here:
and you can visit the_burrito_master for more k'nex stuff here:
and you can visit Imperar and his k'nex supercar made with sketchup here:

The tank is propelled by a motor, and is durable enough to drive off the 2 foot table it's pictured on without breaking. The chain does not jam into the gears, mainly because of a few green connectors guiding it at the bottom and the gears' elevation from the ground. The turret can be made to turn with a motor, but I didn't happen to have an extra motor, so you'll need to figure that out on your own, as well as adding a motor if you don't have the same one I do.

If any part of the instructable is unclear, let me know and I'll add some extra views of the section. Or, if you would prefer it, download Sketchup and the tank's file and look at it from any perspective your heart desires.

Step 1: Step 1

Picture of Step 1

1. Overview
2. Build
3. Build
4. Build
5. Align the sections from 2. and 3. like so.
6. Attach with the sections from 4.

Step 2: Step 2

Picture of Step 2

1. Overview
2.-6. Build.
7. Attach to Step 1.
8. Attach to Step 1.
9. Attach these pieces. Be sure it's on the correct side.
10. Attach this piece.
11. Attach the axle on the opposite side. You will need to reconnect a few pieces.
12. Attach the blue rod to the white connector and add a red rod to the yellow/green/white connectors.

Step 3: Step 3

Picture of Step 3

This step will be short, and shortly explained, so you can enjoy putting the top half of the tank on at once. The large piece you'll be making is symmetrical. 2. and 3. are the opposite sides of the same piece.
1. Overview
2.-3. Build
4. Orient and attach.

Step 4: Step 4

Picture of Step 4

Now it's time to build the last piece, the turret, which took me some time to figure out. I made a few minor changes.
1. Overview
2. Build.
3. Build. This section is symmetrical.
4. Add to the previous section.
5. A few more pieces, and you're done.
6. Connect the turret to the rest of the tank.
7. Add four red gears.
8. Add four more red gears. Look at the pictures in the intro if you need to.

Add the chain by making a long line of links and running the motor in the proper direction to drag it along (or turn the axle if you haven't attached a motor yet). I didn't count how many links there were on each track, but the key is making it small enough so that it doesn't fall off easily, but large enough so that it doesn't heavily restrict the shape of the track. There should be some slack if you lift the tank.


jarretrules (author)2015-01-15

where did you get the knex prints .

Doc Penguin (author)2014-10-12

not bad

OZKNEX22 (author)2013-01-16

i built this it great 4-5* well done mate

guitarshredder123 (author)2012-06-05

nice! your design?

sharpbike123 (author)2011-08-23

Here it is.

sharpbike123 (author)2011-08-22

If i post my 6 wheel drive tank, could you build a turret for it please.

verypoopy (author)2011-04-02

does the chain work for you?

thesupergoalie (author)verypoopy2011-06-19

It works for me!!!
You just have to think about it.
It took me 6hours to complete

verypoopy (author)2011-04-02

does the chain part thing spin/work for you? and do you have any ideas? PLEASE LET ME KNOW!!!!!!!!!!! :)

KNEXFRANTIC (author)2010-08-10

um could you please post a pic of you lifting it

KNEXFRANTIC (author)2010-08-10

awsome also it looks slightly like a bmp1

BrazenRain (author)2010-01-14

Imperar needs more credit for his original sketchup stuff. Take a look here:

MotaBoi (author)2010-01-11


crazyknexkid (author)2009-12-24

did you make this on some sorta online knex builder thing?!?! cuz if you did tell me i wanna know it!!!

BrazenRain (author)crazyknexkid2009-12-25

Google Sketchup. The Sketchup warehouse (online database of models) has individual pieces that were made by Imperar.

Lowney (author)2009-11-01

 This is the best tank on the site!

Mr. Muggle (author)Lowney2009-11-27

hey lowney, What do you think of my new tank, check it out:

Lowney (author)Mr. Muggle2009-11-27

Good work!

Mr. Muggle (author)Lowney2009-11-27

thanks, do you wanna rate?

marlonlaija (author)2009-09-07

will a green motor work

BrazenRain (author)marlonlaija2009-09-07

It depends on the size and torque of the motor. If it's the same one, this should help:
If not, I can provide suggestions if you can give a description/picture.

chopstx (author)2009-08-31

My only complaint is this step. If you can, can you split it into smaller chunks?

chopstx (author)BrazenRain2009-09-02

YES!!!!!!!!!!!!!!!!!!!!!! Thank you!

chopstx (author)chopstx2009-08-31

Otherwise, this instructable and the tank are both very good. 4.5*

gb123 (author)2009-07-19


BrazenRain (author)2009-07-16

Look at the 5th picture in step 2, and the second picture in the intro. The motor locks into the white connector

JonnyDude2008 (author)2009-06-29

hello I have the same shape motor however at a higher rpm which results in lower power do you reckon it could hall the weight?

BrazenRain (author)JonnyDude20082009-06-29

I haven't listed the RPM of the motor I used, so I can't be sure if your motor is different. But, if your motor is too "weak" to move the tank, you can try building a gearbox for it. Put a small blue gear on the motor's axle, and line it up with a red gear on the tank's axle (but probably not the cogs that are already there). The tank's axle will rotate slower, but will have more torque.

JonnyDude2008 (author)BrazenRain2009-06-30

tanks... get it wasn't vry funny lol im gonna attach another motor ive got so it shld be ok awesome tank though

BrazenRain (author)JonnyDude20082009-07-02

This should help if that doesn't work. The axle closest to you is the one that turns the gears of the tank's tracks.

JonnyDude2008 (author)BrazenRain2009-07-03

Thanks. I'm hoping to make it tonight. Have u seen the other version on this site the one that turns?

mettaurlover (author)2009-07-02

this is made of awesomeness.

knexsuperbuilderfreak (author)2009-06-30

not 100 his but good im gonna make it all with a cyber motor and a tertherd motor

ceaser47 (author)2009-06-04

does it shoot?

BrazenRain (author)ceaser472009-06-05

The tank you see there does not shoot, but I'm sure it could be modified to shoot, with that barrel removed or replaced. Or, remove the turret altogether and fit a better gun to the top. It would probably look better, too, if you extended the chassis around it.

DJ Radio (author)2009-05-16

ya, I like it. 4.5*, cuz it aint yours. But i do like that you got his permission and didnt take credit.

The Jamalam (author)DJ Radio2009-05-20

What the hell? cuz it aint yours? What difference does that make!

DJ Radio (author)The Jamalam2009-05-20

If he got permission from The burrito master, and gave credit, then no difference. thus, it makes no difference.

BrazenRain (author)DJ Radio2009-05-20

You said 4.5 because it wasn't mine, but as I see, didn't mean it, so you rated it 4.5 regardless of whether I designed the tank or not. Let's leave it at that and not argue needlessly.

Wicky (author)2009-05-09

Wow doesn't that enormous model lag? Bah after about 50 pieces it starts lagging here =/

BrazenRain (author)Wicky2009-05-09

It did lag on my old computer (2.7GHz, 512mb RAM) but I managed to finish most of the tank with it. The only lag I get on my new computer is from sketchup itself. (quad core 2.4GHz, 4gb RAM) lol.

Wicky (author)BrazenRain2009-05-09

I don't know if the graphics card makes a lot of difference, but then I should have the same problem..3.0GHz dual core/2GB ram here and I just read it uses only 1 core =/

BrazenRain (author)Wicky2009-05-09

I'm using an NVIDIA GeForce 9500GS. Lag didn't get in the way of my work, even when I had 5 copies of the tank in a single file.

Wicky (author)BrazenRain2009-05-09

I use a GeForce 9800GTX+, I must have been doing something wrong in the graphic settings, but I'll just stick to the real thing

the_burrito_master (author)2009-05-09

nice man I see you finally finished it! you should show how you can have more than 1 motor on it.

I would think that the right side of the axle would be mirrored on the left, and would be separated to turn independently. As for the turret, I don't think that blocky blue motor of mine would do. And I don't think I want to use sketchup again after this (because AutoCAD is so much better).

yeah I totally understand. maybe I'll build it again some day.

I just had to rate it 5 stars i mean I made it and the instructable is great!

Oblivitus (author)2009-05-09

Very nice!

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