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.

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

Step 2: Build the Base.

Read all image notes.

Step 3: Make the Walls and Add Them to the Base.

Read all image notes.

Step 4: Make the Axles.

Read all image notes.

Step 5: Make and Add Another Wall.

Read all image notes.

Step 6: Get Your Motor.

Read all image notes.

Step 7: Add the Axles.

Read all image notes.

Step 8: Finish Off.

Read all image notes.

Step 9: You're Done!

Now make 2!

<p>i made the box and then i remodled it i made it smaller</p>
Do you have a pic? I'd like to see it!
<p>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?</p>
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.
I built it and powered a fan with it.
nice man ;) did you like it?
awsome gearbox!
Have you build it yet?
Thanks man!
i made it and turned on the motor but it went the same speed please help. p.s it had freash batteries
Make sure you build the insides exactly like it is on the I'ble.
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
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
Thanks man, I did my best at this 'Ible, used a high quality camera. <br> <br>That's great, there are many uses for it.
Thanks man, I did my best at this 'Ible, used a high quality camera. <br> <br>That's great, there are many uses for it.
take the moter outa one and connect em
I do not understand you.
connect 2 gearboxes
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?
It changes gears? <br><br>I can help you if you send me 1 or more pictures.
its one of my ibles, ill put a pic up here anyway
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
This is better. http://www.balmoralsoftware.com/knex/soma/somaset.htm
Lol. It's all based of this concept: https://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...
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
How did it work out?
It ran smoothly for about 10 seconds then spun out of control
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
Hmm. Try using the second gear instead of the third.
Ok man, good luck!
hi this is AWESOME!
Thanks man! Glad you like it :-)
havent tried it yet but looks like it will work for what im using it for
Ok! What are you using it for?
Nice. Perhaps something for ball machine lifts.
For sure!
now make one that slows down 6 times :)
That is not possible with only K'nex pieces :P<br><br>Do you like it?
Yes it is..
Show me.
Do the exact same thing you have, but backwards. Small gears to large gears. Easy. :)
I have a large 'DOH!' moment now... -___-<br><br>You're right, and I could also use the biggest yellow gear to make it go even faster. Pity that I don't have one.
Thank you (:

About This Instructable



Bio: I like being creative.
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