Knex Ball Machine Lift: Double Stair Lift

About: Hey everyone. I'm Thibault Art and my biggest hobby is to build huge machines in K'nex. I like also to draw a lot and take care of my corn snake. On this page you will find K'nex ball machines, K'nex element...

Hey everyone,

here are instructions for a Knex Ball Machine Lift (The Dubble Stair Lift).

This lift can handle 3 knex balls at the same time and is really easy to make and works very smooth when instructions are carefully followed. Just make sure you have a 12V motor and enough Medium red (grey or yellow) gears, because you'll need about 24 of them. You can also check Step nr1 to see the special pieces you need to complete this build. If you don't have the pieces that you see in Step 1, don't worry, you can easily build this lift without them, it just makes the lift a bit more steady.

If you are interested in making a longer version of this lift, I recommend you to aply a second 12V motor on the top of the lift for a smoother rotation.

If there are any complains, questions or problems, please tell me in the comments below.

Thanks for watching, building,

Thibault Art.

Step 1: Special Pieces You Need:

Step 2:

Step 3:

Step 4:

Stop counting, there are 11 connectors and 21 spacers :p.

Step 5: Important Step:

Make sure that all the black connectors are facing downwards.

Step 6:

Step 7:

Step 8:

Step 9:

Step 10:

Step 11:

11 connectors and 21 spacers.

Step 12: Another Important Step:

Now, make sure that all the black connectors are facing upwards.

Step 13:

Step 14:

Step 15:

Step 16:

Step 17:

Step 18:

Step 19: Go Ahead and Try It Out!

2 People Made This Project!


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7 Discussions


1 year ago

can someone tell me how many pieces this lift contains please so i know if i have all of the parts to be able to build it, and can someone list how many of each part too


2 years ago

Cool! This is one of my favorite lifts from your ball machine by far! Btw, I don't know if it was purposeful, but in the title the correct spelling is "double". :)

3 replies
Thibault Artwww139

Reply 2 years ago

Oh, thanks for noticing. As you can clearly tell, English isn't my best language :p.

MisterBukweetThibault Art

Reply 2 years ago

Do not feel bad about poor English. I have been speaking it for 56 years, and I still goof it up daily..


2 years ago

Thanx for posting this nice instructions! I will build the ones from which i have the pieces. Pity the Green gear isnt in my collection. I am wondering in which Knex box you can find it. Have never seen it before.

1 reply
Thibault ArtKipcorn

Reply 2 years ago

Thanks for commenting and building! Yeah I know, the green gear is a very rare piece that has been discontineud a few years ago. I don't even know from which knex set it comes from : /. I was trying to make the same lift with a large yellow gear instead, But unfortunately, The lift doesn't work that well with a yellow gear.