Tube Claw 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 &...


This is the second new lift featured in my knex ball machine Elysium.

The Tube Claw Lift is one of the most complicated lifts I have ever built. I had multiple problems while building this, the biggest one being the exit, but also things like the crank, the entrance, and the tube-axle connections didn't work from the first time. Surprisingly, this thing works! This version has never failed so far.

I started building this for my ball machine Revolution, with the idea of the lowest claw directly picking up the balls from the floor. At that time I had a lot of troubles with the lift, and after a while it even got too tall for Revolution. So I cancelled that idea, and it was replaced by the Floor Double Arm Lift (which did pick up the balls directly from the floor, that idea was something I really wanted to keep). But I never took the basic mechanism of the now called Tube Claw Lift apart, it just stood there till I retried it after Revolution. Then I got a half working version (the one in Elysium), and after taking Elysium down I did another retry to make the lift work good.

After 3 stages, this version is definitely the best one, so that's the reason why I post it now.

It's very piece consuming for it's height, so don't use it in your own ball machine if you want something quick, easy and piece-efficiently. I've built exactly what I had in mind, and apparently it needs quite some pieces to work properly. Feel free to try it out by yourself, maybe you even come up with something more piece-efficiently.

One disadvantage with this lift: it can only lift one ball at a time. I tested it with multiple balls (a gate wouldn't be required because the lowest claw only takes one ball at a time), but when there are 3 balls in the tubes, pieces in the motor section will most likely snap.

It's a very difficult thing to build, I really did my best and I hope you can follow the instructions. If you're going to build this lift, please read every image note, they are very useful! When you have any problems or questions, feel free to make a comment or send me a message.

Thanks for watching / building!


Step 1: Piece Count

If you want you can count the pieces before you start building.

Here is a list with all pieces included in this lift, named by their original colour:


Green: 134

White: 145

Blue: 216

Yellow: 72

Red: 171

Total rods: 738


Dark-grey: 110

Light-grey: 58

Orange: 131

Red: 47

Green: 17

Yellow: 120

White: 64

Purple: 84

Blue: 42

Total connectors: 673


Blue spacer: 52

Silver spacer: 74

Tan clip: 3

Y-clip: 111

Small blue gear: 1

Big yellow gear: 1

Motor: 1

Total other: 243

Grand Total: 1654

Step 2: Entrance

Let's begin with the entrance.

Step 3: Claws, Part 1

The first of 6 parts. This one is the easiest because you don't have to combine multiple parts yet.

Step 4: Claws, Part 2

Watch closely to the pictures and read all the image notes, especially in this step.

Step 5: Claws, Part 3

Third part of the claws. Again, pay close attention to the pictures.

Step 6: Claws, Part 4

This part is the side of the exit. It differs most from the other parts of the claws.

Step 7: Claws, Part 5

Again 2 sides, with some changes at the end.

Step 8: Claws, Part 6

This is the last claw step. This step shows you how to combine part 1,2,3 with part 4,5. After that we're going to attach the completed claw section on top of the entrance.

Step 9: Exit

After all the complex parts in the previous steps, it's time for something easier. This is the exit, the shortest step in this build.

Step 10: Tube-Axle Connections

These parts connect the tubes with the axle. It was quite difficult to find a way to do this, because there was not much space and the 2 tubes are close to eachother.

Step 11: Axle

In this step we will build the axle. It pulls the tubes up and pushes them down.

Step 12: Motor, Gears and Crank

The last step in this build! 3 things in one, because they're all quite small.

Step 13: Finished!

The Tube Claw Lift is finished!

Always slide the switch of the motor to the right.

Thanks for watching / building!


2 People Made This Project!


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50 Discussions


2 years ago

Wow, that is a lot of Y-clips :) I think I maybe have 15 :P Nice job with it though, nice and dense.

1 reply

3 years ago

WOW.... WOW!!!!.. Another awesome design. I just finished building this lift (picture to come). This was a fun and challenging build. I just have one tiny request in your future builds.... Please remember that my fingers are big and fat and its hard to get into tight areas.... Love your work though....

1 reply

3 years ago

0_o HAND REVEAL!! HYPE HYPE HYPE! seriously though I love the lift sadly I have no large yellow gears :-( anyway I had an idea for a lift but I can't seem to build it so I thought I'd ask you in case you want to; it's sort of like a corkscrew lift however the ball is in a large tube that turns and the screw is sort of inverted (like a skinning spiral staircase inside a tube). hope you like the idea :D

12 replies

Thanks! You can replace the yellow gear with red and blue ones untill you have approximately the same speed.

And that lift idea, do you mean something like the archimedes screw?

Finally given up motorising it (-_-) lol. I'll post instructions for the static loop as it is when I get time :)


3 years ago on Introduction

We made this! Had a problem with the ball exciting - we were using a black and white ball, which apparently is a little bigger than the red and yellow ball. Once we switched balls it worked like a charm! We LOVE your detailed instructions and photos. We have now made 3 of your designs. Thank you!

2 replies

We have made the Floor Double Arm Lift and and the Wheel Lift; I think we may try to make the Ferris Wheel Lift next. We want to see if we can somehow hook them all together.