Connected Arm Lift, a Knex Ball Machine Lift




About: 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 hope you like my stuff, and like always comment, rate &...

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

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

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

Step 3: 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

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

Step 5: Exit

The exit. Here leave the balls the last arm.

Step 6: 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

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

Step 8: 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!




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86 Discussions


3 years ago on Introduction

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?

3 replies

Reply 3 years ago

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


here is mine you can see a instructable with it at

2 replies

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


6 years ago on Introduction

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?

5 replies