Introduction: Connected Arm Lift, a Knex Ball Machine Lift

Picture of Connected Arm Lift, a Knex Ball Machine Lift

Hey everyone!

I present to you the second new lift from my ball machine Euphoria. The first one is here.
The Connected Arm Lift is in my opinion a cool looking lift, with a pretty low piece count.
It works very good, I've never seen a ball fall of the lift.
If you build this lift, read every image note! 

I hope you like it and have much fun with building!



Step 1: Piece List

Picture of Piece List

First you have to count the pieces.
They're all named by their original color.


green: 81
white: 37
blue: 50
yellow: 48
red: 88
grey: 46

Total rods: 350


dark-grey: 15
light-grey: 2
orange: 48
red: 10
green: 26
yellow: 39
white: 11
purple: 89
blue: 23

Total connectors: 263


tan clip: 3
Y-clip: 6
blue spacer: 27
silver spacer: 76
small blue gear: 1
medium yellow gear: 1
medium hub: 1
medium tire: 1
green motor: 1

Total other parts: 117


Step 2: Entrance

Picture of Entrance

We will start building the entrance. Here the balls can enter the first arm.

Step 3: Motor Section

Picture of Motor Section

Here we will build the motor section. It contains the motor, the gears and the axle.
Always slide the switch of the motor to the left.

Step 4: Frame

Picture of Frame

This is the most boring part from the lift... But it's also very necessary so just build it!

Step 5: Exit

Picture of Exit

The exit. Here leave the balls the last arm.

Step 6: Arms

Picture of Arms

Now we will build the four arms. They pass the ball to eachother so it can get from the entrance to the exit.

Step 7: Arm Connections

Picture of Arm Connections

This is the last part from the lift. They connect the arms and the cranks.

Step 8: Finished!

Picture of Finished!

Yay! The Connected Arm Lift is complete!

Thanks for building my lift or watching the ible only.
When you've built the lift send me a photo, then I can add it to this step!
I hope you liked it!

See you!



ses6761 (author)2015-09-28

We just built this lift. It works great for a couple of rotations, then there seems to be a problem with the gears meshing. It starts skipping and binding. Any ideas?

sandroknexmaster (author)ses67612015-09-29

Did you use the same motor as in the instructions? If not, yours might be not strong enough.

ses6761 (author)sandroknexmaster2015-09-29

Yes, the green one.

sandroknexmaster (author)ses67612015-10-03

That's weird, then I suggest you try to place the gears in a different position. Maybe then it will work.

Linkin_J_Knex (author)2015-09-03

I built this ages ago when I first attempted making a ball machine (over a year!) I had no gears and little pieces so this lift was great! (until I realised I didn't have enough pieces to bring the ball back to the start) I am thinking of using it in my second ball machine which will be really long and not very high. :)

ses6761 (author)Linkin_J_Knex2015-09-29

Yes, the green one.

Linkin_J_Knex (author)ses67612015-09-29

Oh, you replied to the wrong person! :D

ses6761 (author)Linkin_J_Knex2015-09-29

Oops! So sorry :)

Linkin_J_Knex (author)ses67612015-09-29

Don't worry :)

Linkin_J_Knex (author)ses67612015-09-29

Sorry what do you mean by that?

Then this lift is a good choice indeed :)

I will probably use this lift as well as other lifts. I have a few knex ball machine ideas :) I'm really inspired for knex and excited to be a larger part of this knex community :)

That's great, keep looking out for stuff here and on youtube, try out some things, and off course try to come up with some new stuff!

Linkin_J_Knex made it! (author)sandroknexmaster2015-09-23

I searched through my files and found out I have a video of the complete lift from years ago! It was my first ever attempt at a ball machine :D

Ha nice!

autumsawesome (author)2015-06-23

here is mine you can see a instructable with it at

that looks cool!

Thanks for building!

TheUnfortunateHobbit (author)2014-10-13

I'm trying to mod this lift, but it never works. NOTHING is the right length.

Hm that's very weird, I've never had trouble with this lift, it always worked great. You can send pics, questions, or any other things I can help you with in PM. I'll do my best to help you out.

btw, 2600th comment :D

Sorunome (author)2013-06-25

Nice lift!

Thanks! :)

hunter999 (author)2013-06-22



Your welcome

cooljupjup (author)2013-02-18

hey ik heb deze lift gebouwd maar heb wat problemn... bij het begin bij die rode stang dan valt me bal er soms over heen als ie aan komt maar ook als die ball vanger ofzo komt dan pakt ie de bal niet. dus kun je me helpe?

Stuur me wat foto's in een bericht, dan kan ik je mss verder helpen.

sorry man kan geen fotos maken maar het is zo dat het rode staafje aan het begin soms te laag zit

En heb je als tegengewicht hetzelfde wiel en dezelfde band gebruikt als in de instructies?


Hm... en welke motor gebruik je?

dezelfde die jij ook gebruikt,.

Sorry maar dan weet ik het niet.
Ik denk dat er dan niks anders opzit dan dat je zelf eens probeert.
Moest het dan nog niet lukken dan sorry maar ik vrees dat er dan niks anders opzit dan hem af te breken.

maar ik gebruik ook die wit zarte balletjes heh. ;p

Ha ill post mine soon. I built the connected arm lift tomorrow.

Ah dat is in ieder geval al een rede waarom ze over dat rode stokje rollen.
Je zou een klein padje kunnen maken dat uitkomt op de zijkant van de lift, dan hebben ze veel minder snelheid en dan rollen ze misschien niet meer door.
Maar je zei ook dat de eerste arm de bal niet opheft?
Dat weet ik niet, misschien kun je wat extra gewicht (niet te veel) vastmaken aan de eerste arm, maar ik ben niet zeker of dat zal werken.

ik zal het probere..maar ik ben op dit moment bezig met een ballmachine en heb die lift van shadowman39 die stepperlift gemaakt maar dan met 4 van die cars maar heb nog 1 extra lift nodg xD

Je kan 1 van mijn andere lifts gebruiken als je wilt :p

je bedoeld die counter parralel arm lift?

Yep of spinning freefall lift.

cooljupjup (author)2013-03-09

HI This lfit works fine it also works with the newer balls! and ihave no problems anymore! :)

Can you send a photo?

Ill send or post it when i finish. cooljupjup should post his!

Good, thanks for building it!

ah no sorry i already destroy it i`am going to build a ballamchine :)


haahah :p

Haha cool!

knex dude 2000 (author)2013-03-12

Where do you get the time to count the pieces? I don't have 76 grey spacers!!!

Most spacers on the axles of the arms can be replaced with connectors.

About This Instructable




Bio: Hey! I'm Sandroknexmaster. I like building with knex, especially ball machines. I live in Belgium. I speak Dutch, but also English and French. I ... More »
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