K'nex Hammer Lift




About: Hi! I'm Ruben, better known as RNB. I'm a student Mechanical Engineering and hence like to build contraptions related to that. I mostly make use of K'nex, which is convenient to use since it is easy to desig...


This is my new (and first) k'nex lift system. I came up with this idea, because the physics teacher was showing us the effect when anything that's heavy (a hammer) hits a light - weight thing. (a small ball) So I made that system with k'nex, and this is the result.

In this lift, a rotating arm goes up, and it comes down real fast, sending the ball up the incline.

The one in the video is a bit different, the one in this Instructable is better.

Hope you guys like it.

Click here to watch the video

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Parts List

These are all the parts you'll need to build the Hammer Lift.

Rods: 221






tan rigid-1

black rigid-1

Connectors: 154

dark gray-14

light gray-13





orange tube connector - 6




Other: 122

blue spacer-48

silver spacer-42

red gear-3     

blue/tan gear-1

small grey gear-1

tan clip-3

blue clip-15

Y clip-14

small wheel band-4

rubber band-1

chain link-7              

battery-powered motor-1

Total: 533

And,  of course, you'll need k'nex balls and tubing

Step 2: Base

You'll start with building the base. It's pretty easy.

Step 3: Right Tower

Again an easy step, next step is harder (finally...)

Step 4: Left Tower

Yeah, a harder step :). This side contains the system that block balls, and let every time one ball pass.

Step 5: Motor

This is a hard part to make, look closely at the quantity of spacers.

Step 6: Hammer

You're nearly finished! Just make the hammer: It's easy.

Step 7: Finished!!!

Congrats, you're done with your Hammer Lift. Here are some tips:

1. The new k'nex balls (the big ones) comes higher than the old ones: If you use them both, be careful at the top of your hill: the big balls could fly off the track.

2. Attach the track as much as possible, this is to save speed, and to reach higher. Also support the track  good: It mustn't be unstable, the balls slow than down quickly.

3. If the arm goes stuck on the system that let 1 ball / time go, make the second and the third picture.

4. If the balls are going to be launched off the entrance path, make it longer. If the balls don't pass, wait till other balls arrive. That balls will push it trough the system that block balls.

Please give a feedback and feel free to comment and rate!

Be the First to Share


    • Book Character Costume Challenge

      Book Character Costume Challenge
    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest

    60 Discussions

    This is a cool design! I have an idea that I might use to make it whack the ball even harder and up a higher track by using some of my modified motors which plug into a wall outlet and spin two to three times faster than any other knex motor! :)


    9 years ago on Introduction

    i made the project and it works great i never thought that the small engine would never pull that hammer all the way around. i wish you would show how to make the rest of the track.

    4 replies

    Reply 9 years ago on Introduction

    I can't add a pic now, because I use the lift on a other way: as transport. The ball gets now hit by the arm, and flies 1M trough the sky, and ends up in a basket.


    Reply 8 years ago on Introduction

    Can you post an instructable on how to modify that to fling the balls that far? I'm definitley going to build this and use it in the new ball machine I'm going to start tommorow! :)


    Reply 8 years ago on Introduction

    I just see, it isn't 1 mile, it's 1 meter :-P. It's easy: Build this instructable, and don't add more track then shown in this Ible. Just cut the tubing off after the short part shown here, and let the balls fly! If you put the lfit also a bit higher up (so add a red box underneath it i.e.), it will go even further.

    So, don't modify, just don't add any more rubbish after the lfit!


    Reply 9 years ago on Introduction

    in the last step have I put some tips how to make the track. I think you can build your own with that.


    8 years ago on Introduction

    Might build but heres 3 questions....

    1. Do you have to have that pathing, can I change it to some different pathing?

    2. I have the motor in the picture (Ignore ball) will it still fit in?

    3. The motor isn't too powerful, does it have to be a strong motor?

    Thankyou, MM8

    12 replies

    Reply 8 years ago on Introduction

    1. It's changeable to yellow 5 - way connectors, although you'll have to find out the new height of the track.

    2 + 3 Attach the motor to a white snowflake connector, and change the spacers/rod. The motor should work, cause my motor is weak too. If it doesn't work, just gear it more down. (again a blue gear on a red, you could change the red gear into a big yellow one, but the motor must be on a different place then0


    8 years ago on Introduction

    Do you have to have the orange tubing connectors, I have none

    Ps: Please reply ASAP