Introduction: Knex Shifting Arm Lift

Picture of Knex Shifting Arm Lift

Hey peeps! Shadowman39 and Tornado96 are back with our second collaboration, the shifting arm lift!

This lift uses two sets of arms that alternate on going up and down. The balls are shifted from one side to the other when the arms move. It uses a double crank at the bottom and a gate system to keep the balls in the lift.

Note: this lift works with both the original and newer Knex balls, but it isn't reliable with the newer balls. Modifying would be a good idea if you want it to work better with the newer balls. 

Push the switch of the motor inwards for smoother movement.

Here's the video of the lift in action:

Direct video link

So, if you want to build it, let's shift to the next step!

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Step 1: Piece Count (Optional)

Picture of Piece Count (Optional)

Well, you won't get very far without pieces will you? So here are the pieces you'll need to salvage to build the lift. 

Rods: 294

green- 58
white- 67
blue- 93
yellow- 34
red- 32
gray- 10

Connectors: 244

dark gray- 40
light gray- 1
red- 28
green- 32
yellow- 38
orange- 24
white- 9
blue- 15
purple- 57

Other: 89

blue spacer- 26
silver spacer- 28
tan clip- 7
Y clip- 24
small blue/brown gear- 1
red gear- 2
newer-style battery-powered motor (green)*- 1

Total: 627

*You can use a different motor if you wish, but you'll have to modify the motor section.

Step 2: The Base and Crank

Picture of The Base and Crank

To start off, let's build some of the base and crank. Warning: after building the crank, you might feel a bit cranky. Just ignore that feeling and move on to the next step. 

Throughout this Instructable, make sure to follow the picture descriptions as well as the pictures.

1. Build a section of base tower.
2. Another view.
3. Close-up.
4. Build a crank section.
5. Add it to the tower.
6. Build this middle tower thing.
7. Another view.
8. Attach it to the rest of the tower and crank.
9. Build another crank section.
10. Connect it to the other crank.
11. Build the other edge of the tower.
12. Another view.
13. Combine it with the tower. Make sure to slide the yellow rod of the crank all the way out. If you don't, the lift will be prone to utter destruction.

Well that's it! You can figure out the rest without pictures. Good luck! :-D

Step 3: Motor and Gears

Picture of Motor and Gears

Well, the lift wont go very far without a motor, will it? So now you'll see how to arrange the motor and gearing for the lift. Pay close attention to the spacing to avoid any gear spasms.

1. This may be the hardest part of the entire instructable. Handle with care.
2. Another view.
3. Another view.
4. Attach to the base.
5. Another view.
6. GEARS!!!!! (The two sets of gears without rods are placed on rods that are already on the lift)
7. Close-up view of one of the gears.
8. Attach gears to the base.
9. Build this.
10. Attach it to the base covering the gear section.

Step 4: The Gatekeeper

Picture of The Gatekeeper

Now you will be building the connections from the crank to the arms and building the gatekeeper, the warrior sworn to protect the lift from balls trying to enter more than once at a time (he's armed with an enchanted diamond sword, so I wouldn't mess with him if I were you).

1. Build this.
2. Another view (pay close attention to the spacers).
3. Attach to the base.
4. Build this (slightly more complex than the last one).
5. Another view.
6. Attach to base.
7. What you should have so far.

Step 5: Ball Distribution Apparatus

Picture of Ball Distribution Apparatus

After this step, you'll be finished! ...with the base. :-) This step is a little hard to follow so pay attention!

1. Build this.
2. Attach it to the base.
3. Build this.
4. Attach to the base.
5. The gate.
6. Attach to the base (MAKE SURE that the blue rods are facing upwards.
7. Closer view (notice the gatekeeper is attached to this mechanism).
8. The entrance track (notice the gray connectors).
9. Another view.
10. Another view.
11. Attach to the base (note that the blue rods go through the gray connectors, they act as the gate).
12. Side supports.
13. Completed step.

I bet you're already having fun watching the mechanisms. You've turned it on just to see what it does haven't you. ;-) If you haven't, then you're probably turning it on right now. :-D

Step 6: The Tower (Part 1)

Picture of The Tower (Part 1)

Now you will begin to build the tower and make the lift taller!

1. Build the tower section.
2. Another view.
3. Attach the tower to the base. 
4. Another view.
5. Yes, I know, this part is difficult to build. 
6. Connect it to the crank arm.


Step 7: The Tower (Part 2)

Picture of The Tower (Part 2)

As the title suggests, this is Part 2 of the tower.

1. Build the tower.
2. Another view.
3. Attach the tower to the tower (that makes a lot of sense).
4. Another view.
5. Uh oh! Another one of these!
6. Connect it to the lower arm.

I hope its not getting too repetitive. ;-)

Step 8: The Tower (Part 3) and Exit Track

Picture of The Tower (Part 3) and Exit Track

This is the last of the tower. You'll also build the exit track.

1. Build the tower.
2. Another view.
3. Attach the last part of the tower.
4. Another view.
5. A close-up of the upper arm connection.
6. Build these track supports.
7. Attach them to the top of the tower.
8. Build the exit track.
9. Attach it to the supports.

Well, that's as tall as this lift gets. Feel free to make it taller though! :-)

Step 9: The Arms

Picture of The Arms

If the lift didn't have arms, it would have to be called the shifting lift, and that doesn't make much sense. Plus the balls won't go very far without the arms to bring it up. Therefore, you must build the arms!

1. These are the arms that belong on the left side of the tower.
2. Another view.
3. Attach the arms to the tower.
4. A closer look.
5. One of the arms on the rights side.
6. Another view.
7. Attach like so.
8.Here is the last arm that is placed at the top.
9. Another view.
10. Attach to the tower.

How cool would it be if they could shake hands...

Step 10: You're Done!

Picture of You're Done!

Congrazzledazzles! You have finished the shifting arm lift! All you have to do is get some balls and turn it on! Push the switch towards the inside of the tower and watch it go! This lift can be made taller for all of your ball machine-ing needs.

If your lift doesn't work well, go to the next step.

Remember to comment and subscribe to both of us!

Thanks for viewing!

© ShadowBakon Laboratories, 2013

Step 11: Modifications

Picture of Modifications

A step after the end step? What is this?? Anyway, this step covers things you can try if your shifting arm lift doesn't work properly. There are two different examples in this step.

The first thing you can try is a simple fix. This version of the lift was built by koolcoasterkid (pictures 1-2). All he did to fix it was replace a blue rod with a yellow rod. This can be seen in picture 2.

If your lift still doesn't work, you can build Sorunome's version, shown in pictures 3-4. He shifted the end part of the arm over by 2 blue spacers towards the middle of the lift, as shown in picture 4. Notice the yellow rod is still in place of the blue rod.

Hopefully by now your lift is working nicely!


The Knex Inventor (author)2016-06-04

Nice lift! I think I will use this in my next ball machine if I can get it to work with a green motor.

Thanks! The version of the lift in this Ible uses a green motor, so you shouldn't have to do much modifications.

BTW, what is different about the newer K'NEX balls?

The newer balls are slightly larger and lighter than the original balls.

Oh, I see. Thanks!

You're welcome! :-) I now have a couple of tethered motors, so I don't have to modify it.

Borisv9 (author)2016-08-08

the ball always falls of at the 3rd arm and doesn't reach the 4th arm :( what do I do?

Shadowman39 (author)Borisv92016-08-09

I'm sorry to hear that, did you try the modifications in step 11?

Borisv9 (author)Shadowman392016-08-11

I added a yellow rod instead of a blue one, it now works. thanks though

Linkin_J_Knex (author)2015-10-15

building it but it keeps jamming and snapping for some reason. any idea why?

Maybe it will fix itself when it's done. the problem is that the entrance bit(the one right in front of the motor that is step 1 on the guard bit ) gets pulled down too far and goes vertical, stopping the crank from working. I'm hoping once the arms are in, they sort of pull the entrance a bit. anyway, I remember building this years ago (before I had Instructables) and had the same problem. anyway this gr8 lift will be in my next ball machine :D

Built it! Really simple fix, Add a yellow rod here (The one that goes through 3d connector and stops just before the snowflake)

And now I have built the entire ball machine and this lift doesn't work...:(

Sorry for replying so late, I bet by now your machine is already posted.

www139 (author)2015-09-26

Nice lift! Not very many pieces either which makes it ideal. Nicely done!

Martin.Daina.Selby made it! (author)2015-02-08

Great Model

That's looking nice, thanks for building!

TheUnfortunateHobbit (author)2013-10-29

mine keeps stuffing up. For some reason the cranks and the gatekeeper are at the wrong lengths, and they keep stopping the motor

Do you have a picture of that crank area?

oops no fixed it

koolcoasterkid (author)2013-09-14

I made it. Works good. Looks to be a good addition to my machine.

Nice! Looking forward to seeing pictures.

Sent pics. A note for future builders, I replaced the blue rod on the arms with yellow rods and it improves reliability.

I uploaded the pictures but they were rotated the wrong way, even when I rotated them myself. I'm not sure what the problem is.

Sorunome (author)2013-01-27

Nice one! :D
How come you guys do so many collabs recently? :P

Shadowman39 (author)Sorunome2013-01-27

Thanks! We've only done two collabs, I wouldn't call that a lot. :-P

Sorunome (author)Shadowman392013-01-27

What about the other 3141592653589793238462643383279502884197169399375105?

Shadowman39 (author)Sorunome2013-08-14

Did you memorize those?

Sorunome (author)Shadowman392013-08-25

erm, yes.

Shadowman39 (author)Sorunome2013-08-25

Nice :-P

Sorunome (author)Shadowman392013-08-25

no, not nice, i once knew far more.

Shadowman39 (author)Sorunome2013-08-25

I only memorized the first 6 digits, lol.

Sorunome (author)Shadowman392013-08-25

i once knew 108
the key to knowing pi digets is boring biology lessons. don't question me. never.

Shadowman39 (author)Sorunome2013-08-25

Biology was boring for me as well. :-P

Sorunome (author)Shadowman392013-08-25

It was only boring to me due to slow pacing in the lessons.

Tornado96 (author)Sorunome2013-01-29

I knew there was something fishy... those are the digits of pi

Sorunome (author)Tornado962013-01-29

jup, lol

Shadowman39 (author)Sorunome2013-01-28

We never posted those collabs. :-)

HanShotFirst (author)2013-03-08

what other types of balls can i use, i dont have those,

Shadowman39 (author)HanShotFirst2013-03-09

If you don't have Knex balls, you could try golf balls.

www139 (author)2013-02-12

I'll use this(hopefully)on my next ball machine

Shadowman39 (author)www1392013-02-13

Cool, thanks!

www139 (author)Shadowman392013-02-13

you're welcome!

cooljupjup (author)2013-02-03

nice!. it works with the black white balls?.

Shadowman39 (author)cooljupjup2013-02-03

Thanks, and yes it works with those balls, but not as accurately, so you'll have to modify a bit.

cooljupjup (author)Shadowman392013-02-07

it works with the black/white balls i did`nt modify anything

Shadowman39 (author)cooljupjup2013-02-08

That's good. When we tried it out it wasn't as accurate, so I guess it's different for other people.

cooljupjup (author)Shadowman392013-02-09

hahahahaah okay :)

Tom Buckey (author)2013-01-31

Looks good. :)

About This Instructable




Bio: On my page you'll find lots of different Knex projects, from ball machine lifts to useful items. I hope you enjoy!  _______________________ Current avatar ... More »
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