Knex Double Helix Lift

Introduction: Knex Double Helix Lift

About: On my page you'll find lots of different Knex projects, from ball machine lifts to useful items. I hope you enjoy!  _______________________ Current avatar: Target of my skeeball machine Past avatars...
Since lots of people like this lift, I decided I would make an Instructable of it. This is the first Knex spiral lift that has two spirals instead of one. This allows twice as many balls to be lifted up into the tower than the original spiral lift. It's also the first to use tubing for the spiral, which makes it perfectly round.

This lift is a copy of the one I used in Wipe Out, except it's shorter, it uses a battery-powered motor instead of an electric one, and the tracks going in and out of the tower are different. It can be built with only one spiral, but the bottom where the balls come in might have to be changed. A cool thing about this lift is that the platform and shaft can be on any side of the tower because the double helix is in the center. It's also easy to modify.
This is my first Instructable, and it took me a long time to make because the pictures took a very long time to upload.

Here's all the pieces you'll need to build the double helix lift:

Tan (rigid)-1
Total rods:307

Dark Gray-54
Light Gray-0
Blue 3D-41
Purple 3D-71
Total connectors:262

RC Tubing- 2 pieces, each 3 feet, 5 1/2 inches long
Battery-Powered Motor-1
Black Y Clip-17
Tan Clip-10
Blue Spacer-40
Silver Spacer-28
Small Tan (or Blue) Gear-4
Red Gear-1
Large Yellow Gear-1
RC Tubing Splicer-2
Total other:106

Grand Total: 675 pieces

If you have all these pieces, let's get building!
I hope you like it!

Here's a video of the lift in action:

Click here to view the original double helix lift, used in Wipe Out:

Step 1: The Double Helix, Part 1

To start out, let's build the core of the double helix. The red rods that help make it sturdy are in a repeating pattern all the way up. The tubing will go on it in the next step.

Step 2: The Double Helix, Part 2

Now you will put the tubing on the core. Slide the dark gray connectors on the tubing first; then connect the two pieces of tubing onto the core.

You are now done building the double helix; set it to the side and start building the base.

Step 3: The Base, Part 1

This is the part of the tower that the double helix will be attached to, and it will have all the gears (don't forget the motor). This step is very simple.

Step 4: The Base, Part 2

This part of the base will hold a big yellow gear. It goes on top of part 1.

Step 5: The Base, Part 3

This step is very easy. It's just a small section that will go into the side of the base.

Step 6: The Base, Part 4

This is the final part of the base.

Step 7: Connecting Parts 1-4 of the Base

In this step, you'll put parts 1-4 together to complete the base. Part 2 goes on top of part 1. Parts 3 and 4 go into the side.

Now that you've finished the base, it's time to move on to the bottom of the tower.

Step 8: The Bottom of the Tower

Now it's time to build part A and B of the bottom. Part A is the platform where the balls are loaded onto the double helix. Part B is a track leading to the platform.

Step 9: Connecting the Bottom to the Base

In this step, you will connect the bottom to the base.

After you're done with all that, it's time to build the tower.

Step 10: The Tower, Part 1

Now you're going to build the shaft. This is only one side of the tower. Make sure to line up everything the best you can. The two sides of the shaft are different, so pay close attention to the pictures.

Step 11: The Tower, Part 2

For this step, build the rest of the tower.

Step 12: Connecting Parts 1 and 2 of the Tower

In this step, you'll complete the tower. Part 2 doesn't have a top or bottom, so it can go on part 1 either way.

Step 13: Connecting the Tower to the Bottom

Connect the tower to the bottom. Make sure to connect all the rods on the shaft to the bottom platform.

Step 14: The Top, Part 1

This is the top of the tower where the ball will exit from.

Step 15: The Top, Part 2

This is the track that balls exit when they get to the top.

Step 16: Inserting the Double Helix

It's (finally) time to put the double helix into the tower. The tan rod should go through the big yellow gear and the base.

Step 17: Connecting the Top Onto the Tower

You're almost finished! When putting the top on, the yellow rod on top of the double helix should slide into the center on the top.

Step 18: Finished!

Congratulations, you are now finished with the Double Helix Lift!

Just add balls and turn on the motor, and you're ready to roll (well, the balls are, anyway).

If you have any questions, feel free to ask!

1 Person Made This Project!


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165 Discussions


2 years ago

How high can you make it? I need a really tall, skinny lift and this one would work perfectly if I could extend it.


Reply 2 years ago

Thanks! I will be building the inverted helix and extending it.

The Knex Inventor
The Knex Inventor

4 years ago

Awesome lift! Wish I had that tubing...


Reply 4 years ago

Thanks! If you want, you could try to build it with flexi-rods, others without tubing have done that.

The Knex Inventor
The Knex Inventor

Reply 3 years ago

I will also look into purchasing some tubing.

The Knex Inventor
The Knex Inventor

Reply 3 years ago

Great idea! I will have to try that.


9 years ago on Introduction

Where can you get the big yellow gears these days?


Reply 9 years ago on Introduction

Thanks knex dosnt sell them any more soo..... yaehhhhhh...........


Reply 8 years ago on Introduction

try knex user group ,they sell everything


6 years ago on Step 18

this lift is by far the best of any helix lifts that I have built... Great design, and look for it in one of my future machines....


Reply 6 years ago on Step 18

Thank you! I'm glad to hear that it works well. Looking forward to your next machine. :-)


Reply 6 years ago on Introduction

In my build, I replaced the dark gray connectors holding the purple RR rail with orange rail connectors.. the balls roll up the lift much smother..