Check out my Knex Army Knife too!

Hi guys, here are the instructions for my K´nex gearbox.

You can increase speed by approx. 6x compared to the original K'nex motor speed. It packs a punch, the box construction is very strong. I dropped it some times and only 1 thing came off. The gearbox is easily upgradeable to reach higher speeds, but my K'nex motor can't provide more power than what it's now. The gearbox is nicely hidden in a fairly small and strong box.


- Colorful!
- Strong
- Compact
- Easily upgradeable
- Looks pretty nice
- 6 times faster rpm compared to the original K'nex motor rpm


- Takes some time if you want to change something inside
- You need a pretty strong K'nex motor

Tell me what you think, and don't forget to rate!

Well, let's build this thing!


Step 1: Piece count.

Picture of Piece count.
This is the excact piece count.


Yellow -------- 7
White --------- 18
Purple 3d ---- 32
Blue 3d ------- 4
Red ------------ 10
Tan clips ------ 8
Blue clips ----- 5


Green --------- 86
White ---------- 70
Strong red ---- 3


Blue spacers - 20
Big gears ------ 3
Small gears --- 2
Motor ----------- 1

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i made the box and then i remodled it i made it smaller

H1T4TCH1 (author)  chet.damrill.39 months ago
Do you have a pic? I'd like to see it!
rickmcc11 months ago

The 3rd (and final) axle does not need the larger yellow gear on it does it? Seems the speed multiplier gears (large yellow drives smaller blue) finishes on the 3rd axle's small blue gear. The yellow gear should not do anything useful should it?

H1T4TCH1 (author)  rickmcc10 months ago
You are right. I only put it there to be able to extend the box even more if I wanted to. The multiplier indeed finishes on the small blue of the 3rd axle.
nm284312 years ago
I built it and powered a fan with it.
H1T4TCH1 (author)  nm284311 year ago
nice man ;) did you like it?
nm284312 years ago
awsome gearbox!
H1T4TCH1 (author)  nm284312 years ago
Have you build it yet?
H1T4TCH1 (author)  nm284312 years ago
Thanks man!
knexboy5862 years ago
i made it and turned on the motor but it went the same speed please help. p.s it had freash batteries
H1T4TCH1 (author)  knexboy5862 years ago
Make sure you build the insides exactly like it is on the I'ble.
TLF932 years ago
nice job it's really cool and do you think if i try to put two more gears on it, will it go even faster
H1T4TCH1 (author)  TLF932 years ago
Yes you could do that, but I think it will slip faster when you connect the final gear onto something.
this is a great ible, clear pics and instructions. made mine into a fan
H1T4TCH1 (author)  super knex builder3 years ago
Thanks man, I did my best at this 'Ible, used a high quality camera.

That's great, there are many uses for it.
H1T4TCH1 (author)  super knex builder3 years ago
Thanks man, I did my best at this 'Ible, used a high quality camera.

That's great, there are many uses for it.
GASSYPOOTS3 years ago
take the moter outa one and connect em
H1T4TCH1 (author)  GASSYPOOTS3 years ago
I do not understand you.
connect 2 gearboxes
zmxninja3 years ago
Can you help me; I have got a gearbox which can change gears but i cant fit it into a neat little box like yours, can you help?
H1T4TCH1 (author)  zmxninja3 years ago
It changes gears?

I can help you if you send me 1 or more pictures.
its one of my ibles, ill put a pic up here anyway
H1T4TCH1 (author)  zmxninja3 years ago
I see. Well, you can start off by building my creation first, to get an idea of how it all fits together. Then, you can attempt to make a box for yourself.
i have, 4 times... lol pretty helpful
H1T4TCH1 (author)  zmxninja3 years ago
This is better. http://www.balmoralsoftware.com/knex/soma/somaset.htm
H1T4TCH1 (author)  zmxninja3 years ago
Lol. It's all based of this concept: http://www.instructables.com/id/Knex-Cube/ except it's mixed with yellow connectors in my version.
Im goin hook this up to my ferris wheel...
H1T4TCH1 (author)  patriots88883 years ago
Is the ferris wheel really heavy, or not? If so, there is a chance that it won't work.
its relativly lighweight..ill try it today
H1T4TCH1 (author)  patriots88883 years ago
How did it work out?
It ran smoothly for about 10 seconds then spun out of control
H1T4TCH1 (author)  patriots88883 years ago
Hmm... Spun out of control? Do you have some more details maybe I can help.
it was going really fast, the ferris whell tipped over and the motor just made a clicking noise
H1T4TCH1 (author)  patriots88883 years ago
Hmm. Try using the second gear instead of the third.
H1T4TCH1 (author)  patriots88883 years ago
Ok man, good luck!
Orangepanda3 years ago
hi this is AWESOME!
H1T4TCH1 (author)  Orangepanda3 years ago
Thanks man! Glad you like it :-)
cool kid #13 years ago
havent tried it yet but looks like it will work for what im using it for
H1T4TCH1 (author)  cool kid #13 years ago
Ok! What are you using it for?
mahmel3 years ago
Nice. Perhaps something for ball machine lifts.
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