Introduction: K'nex Gearbox: Make Your K'nex Motor 6x Faster!

Picture of K'nex Gearbox: Make Your K'nex Motor 6x Faster!
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

Step 2: Build the Base.

Picture of Build the Base.

Read all image notes.

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

Picture of Make the Walls and Add Them to the Base.

Read all image notes.

Step 4: Make the Axles.

Picture of Make the Axles.

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Step 5: Make and Add Another Wall.

Picture of Make and Add Another Wall.

Read all image notes.

Step 6: Get Your Motor.

Picture of Get Your Motor.

Read all image notes.

Step 7: Add the Axles.

Picture of Add the Axles.

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Step 8: Finish Off.

Picture of Finish Off.

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Step 9: You're Done!

Picture of You're Done!

Now make 2!


pephooh (author)2017-09-20

is it possible to slower the motor instead of faster?

dynamite_kid (author)2017-09-04

Nice I made it faster and changed it for my knex marble machine and it works a treat really cool

chet.damrill.3 (author)2014-11-15

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

H1T4TCH1 (author)chet.damrill.32014-12-04

Do you have a pic? I'd like to see it!

rickmcc (author)2014-09-10

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)rickmcc2014-10-23

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.

nm28431 (author)2013-05-17

I built it and powered a fan with it.

H1T4TCH1 (author)nm284312013-09-25

nice man ;) did you like it?

nm28431 (author)2013-04-11

awsome gearbox!

H1T4TCH1 (author)nm284312013-05-09

Have you build it yet?

H1T4TCH1 (author)nm284312013-05-09

Thanks man!

knexboy586 (author)2013-01-27

i made it and turned on the motor but it went the same speed please help. p.s it had freash batteries

H1T4TCH1 (author)knexboy5862013-02-01

Make sure you build the insides exactly like it is on the I'ble.

TLF93 (author)2013-01-31

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)TLF932013-02-01

Yes you could do that, but I think it will slip faster when you connect the final gear onto something.

super knex builder (author)2012-07-04

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.

That's great, there are many uses for it.

Thanks man, I did my best at this 'Ible, used a high quality camera.

That's great, there are many uses for it.

GASSYPOOTS (author)2012-03-24

take the moter outa one and connect em

H1T4TCH1 (author)GASSYPOOTS2012-03-27

I do not understand you.

GASSYPOOTS (author)H1T4TCH12012-03-27

connect 2 gearboxes

zmxninja (author)2012-02-15

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)zmxninja2012-02-17

It changes gears?

I can help you if you send me 1 or more pictures.

zmxninja (author)H1T4TCH12012-02-19

its one of my ibles, ill put a pic up here anyway

H1T4TCH1 (author)zmxninja2012-02-23

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.

zmxninja (author)H1T4TCH12012-02-25

i have, 4 times... lol pretty helpful

H1T4TCH1 (author)zmxninja2012-03-06

This is better.

H1T4TCH1 (author)zmxninja2012-03-06

Lol. It's all based of this concept: except it's mixed with yellow connectors in my version.

patriots8888 (author)2011-09-10

Im goin hook this up to my ferris wheel...

H1T4TCH1 (author)patriots88882011-09-10

Is the ferris wheel really heavy, or not? If so, there is a chance that it won't work.

patriots8888 (author)H1T4TCH12011-09-11

its relativly lighweight..ill try it today

H1T4TCH1 (author)patriots88882012-02-17

How did it work out?

patriots8888 (author)H1T4TCH12012-02-17

It ran smoothly for about 10 seconds then spun out of control

H1T4TCH1 (author)patriots88882012-02-23

Hmm... Spun out of control? Do you have some more details maybe I can help.

patriots8888 (author)H1T4TCH12012-02-23

it was going really fast, the ferris whell tipped over and the motor just made a clicking noise

H1T4TCH1 (author)patriots88882012-03-06

Hmm. Try using the second gear instead of the third.

H1T4TCH1 (author)patriots88882011-09-11

Ok man, good luck!

Orangepanda (author)2011-12-26

hi this is AWESOME!

H1T4TCH1 (author)Orangepanda2012-01-09

Thanks man! Glad you like it :-)

cool kid #1 (author)2011-11-13

havent tried it yet but looks like it will work for what im using it for

H1T4TCH1 (author)cool kid #12011-12-08

Ok! What are you using it for?

mahmel (author)2011-09-10

Nice. Perhaps something for ball machine lifts.

H1T4TCH1 (author)mahmel2011-09-10

For sure!

getoutofhere623 (author)2011-09-07

now make one that slows down 6 times :)

H1T4TCH1 (author)getoutofhere6232011-09-08

That is not possible with only K'nex pieces :P

Do you like it?

GrandeSwag (author)H1T4TCH12011-09-08

Yes it is..

H1T4TCH1 (author)GrandeSwag2011-09-08

Show me.

GrandeSwag (author)H1T4TCH12011-09-09

Do the exact same thing you have, but backwards. Small gears to large gears. Easy. :)

H1T4TCH1 (author)GrandeSwag2011-09-10

I have a large 'DOH!' moment now... -___-

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.

~KGB~ (author)2011-09-06


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