Introduction: Knex Ball Machine - TurnPike

About: K'nex is my thing!

Here is my latest ball machine, TurnPike. It has one track measuring over 32 feet, and features lots of winding, looping, banked-turn goodness that takes a single ball over 20 seconds to navigate (plus the lift). You will notice that it is very similar to my previous ball machine, "Loopy". However, apart from being much larger, TurnPike also has extra supports added, a new way of banking the turns and a slightly different lift, that allows the roller-coaster tubing to go up the lift and join the tubing at the top, making a continuous loop.



Step 1: Preliminary Notes...

Before we start, there are a few things I need to warn you of that will be coming up in the forthcoming steps.

#1, I label my photo numbers, and give specific instructions for each photo. It is very important. Also, if I label multiple photos, say example photos 12-15, it means that photos 12 through 15 are all following the same command, so if I say "Photo #2-4: Build part A" It means that photos 2, 3, and 4 are all different photos of one piece you should build, so don't build the same piece thrice.

#2, This instructable is divvied up into smaller parts that connect onto larger parts. Now, this ball machine is built on a Blue rod X Blue rod frame, and there are cross supports made up of an orange connector with two white rods on each end, being skewered in the middle by a yellow rod. This forms an X shaped support, as seen in photo #2 of this step. This will come up everywhere in this instructable. Now, if part A has just a yellow rod at one end, and it connects to part B, which has an orange-and-white assembey, there is a good chance that when they are connected that the yellow rod will go through the hole in the orange connector. See for example, photos 3-5.

Photo 3: Not that this piece has an orange connector with white rods sticking off the end there. First you will build this piece (not now, it comes up in step 12...)
Photo 4: Next you will build this part, which has a yellow rod sticking out.
Photo 5: Now the pieces from photos 2 and 3 are connected, and the orange connector with the white rods has a yellow rod going through it.

This kind connection also happens all over the place in this instructable, so be wary.

#3 Sort of an add-on to my last point... Concerning the yellow rod/orange-connector-and-white-rod cross supports... They are everywhere, and very often, not all of the four points will end up connecting to a connector. See for example photo #6. One end of that yellow rod isn't connected to anything, and that will often be the case, though it might be the orange connector/white rods that aren't connected.

#4 Lastly (and least important...), you may not be able to see them all, but on every tracking piece, there are four dark grey connectors. See Photo #7. Also, the dark grey connectors also point in the direction that the ball will roll over said tracking piece.

I think that's just about it! If you're all ready lets dive into this project!

Step 2: Piece List

This is whopper of a piece list. I've tried my very best in making accurate counts, but on a project this size, there are bound to be counting errors. Please forgive me. I think, however, that my counts wont be off than about 5% of the total number of any given piece.

Best of luck to you!

Dark gray (one slot) - 504
Light gray (two slot) - 12
Red - 145
Green - 37
Yellow - 77
Orange (straight, two slot) - 365
White - 13
Orange tracking (yellow with the nib) - 201
Blue 3d - 523
Purple 3d - 912

Green - 477
White - 727
Blue - 1433
Yellow - 404
Red - 1
Gray (if you have a black rod, use it)  - 1

Tan Clip - 18
Blue spacer - 8
Silver spacer - 24
Y-Connector - 4
Chain links - 52
Red gear (as seen in the photo for this step) - 8
Motor/Power pack - 1
Roller coaster tubing - 65 feet.
Balls - As many as you can get! I had 10, less would work, but the more the merrier!

Total: 5946

All ready! GO!

Step 3: The Lift

This is the aforementioned lift. For some strange reason this pretty basic lift took 54 photos to make instructions of.

At least its thorough.

1-3: The chain. There are 52 links in it, with a red connector on every 3rd link. The way it works out, there should be one spot with a gap of four chain links between connectors. Also, make sure that the connectors are facing the right way on the chain.
4-6: Build this long chunky thing.
7: Make these two panel things. Remember the grey spacers, and note that the heads of them are different to each other.
8-9: Make these three gear assemblies. They are all identical.
10: Build this thing.
11: Build this thing too.
12: And make this guy.
13: Connect the three parts made previously together like so.
14: Make this panel (pay attention to the 3d connectors!
15: Build this panel too.
16: Put them together.
17: Add that bit you made earlier in at the top.
18-19: Put in that big chunky thing you made a while back. Don't put it in upside down. Mind where the silver spacers go.
20: Time to correct a mistake I made. (Sorry...) See that blue rod that I'm pointing to? Take it out.
21: Make this little bit
22: Put it in where you took the blue rod out.
23-25: Put in them railings you made.

Step 4: Track Piece #1

The first of many track pieces to come.

1: Make this thing.
2: Make these four things.
3: Snap on the four bits you made onto the first bit you made.
4-5: Make this guy.
6-7: Attach it onto the part you already made.
8: Build these two things.
9: Make this thing too.
10: Put them together like so. You'll be making tons of these parts for this ball machine.
11: Make two more.
12: Build one of these longer tracking pieces.
13-14: Put the track pieces on top of the growing base that you've been building.
15: Make this part.
16: Build this part too.
17: Put the previous too bits together.
18: Make this bit
19: Add it onto that part you just made.
20-21: Make this tracking piece.
22-23: Put it onto the part you just built beforehand.
24-25: Attach the two bits you've made in this step together.
26-28: Attach the whole thing to the lift you built in the previous step.


Step 5: Track Piece #2

Shorter than the previous step. Good luck!

1: Make this piece.
2: Make this thing.
3: Build this too.
4: Connect the things built in photos 2 and 3.
5-6: Make this bit.
7-8: Make this similar bit.
9: Build this long thing.
10-11: Connect the two track pieces to the long thing.
12-13: Connect that part you made in photo 4.
14-15: Finally, add the part you made in the 1st photo.
16-19: Connect it to your growing ball machine.

Nice work. Let's move on.

Step 6: Track Piece #3

The third of the track pieces.


1-2: Make this part.
3-5: Make this big panel.
6: Connect the two.
7-8: Build this panel.
9-10: Connect it to the part you previously made.
11-12: Build this bit.
13-14 Connect it onto the structure you've been building.
15-17: Make this chunk.
18-19 Connect it as well.
20-21: Make this arm thing.
22-23: Snap it onto the main structure.
24: Make these two track pieces.
25: Make this track piece as well.
26-27: Build this longer track piece.
29-31: Put the track pieces on the top of your structure.
32-35: Put it onto the lift and things that you've been building up to this point.

Now that we have three different track pieces going in three different directions, lets see if we cant start connecting them.

Step 7: Track Piece #4

That's right. Number 4.

1: Build this part.
2: Make this too.
3: Also build this.
4: Attach the things from photos 1 and 3.
5-6: Now snap in the thing from photo 2.
7: Make this.
8-9: Make this tracking piece.
10: Make this track bit too.
11-12: Put the track pieces in on the top of the part you made earlier in this step.
13-15: Snap it onto the rest of the ball machine as shown.


Step 8: Track Piece #5

A long, but simple step. Go!

1-2: Make this panel.
3: Then build this panel.
4-5: Connect the two.
6: Make this thingy.
7-8: Add it on to the chunk you just made.
9-10: Build this panel.
11-12: Connect it to the main bit.
13: Make this tracking piece.
14: Add it on top as shown.
15: Build these three bits.
16: Make this part - note that the blue rod is on the second slot, not the middle one.
17: Connect the three bits to the track piece.
18-19: Make this tracking piece.
20: Connect it to the other track piece you just made to get this weird thing.
21-22: Put it onto the big frame that you made earlier.
23-26: Connect it all to your ever expanding ball machine.

Now some of the track is connected, at least!

Step 9: Track Piece #6

A bit of a wonky piece, but it fits right into what you have already completed very well.

1-2: Build this part. Note that the blue rod on the track connector is on the side slot, not the middle one.
3-5: Make this track part.
6-7: Put the two together.
8-9: Make this panel.
10-12: Make this part. Do yourself a favor and pay tons of attention to the 3d connectors.
13-14: Attach the two panel-ish pieces.
15-17: Build this longer track piece.
18-19: Snap that long track bit onto the top of the frame you just made.
20-21: add that weird piece you made first onto the end like so. If you made it properly, it should droop sadly.
22-24: Connect it all up to the main lift/track piece.

Yay! We have track on the left of the lift too now.

Step 10: Track Piece #7

Why wouldn't the shrimp share? Finish this step, and find out the thrilling reason in step ten.

1-2: Build this panel.
3-4: Make this thing too.
5: Connect them!
6: Build this chunk.
7-8 Add it on too.
9-10: Build this half-tower thing.
11-12: Also connect it to the frame you're building on.
13: Build these two track pieces.
14: Put them in!
15-17: Attach them onto the main ball machine as shown.

Moving on...

Step 11: Track Piece #8


Also, sorry for the somewhat dark photos in this step, I must have accidentally changed something on my camera...

1-2: Build this panel.
3-4: Make this panel as well.
5-6: Connect the two.
7-8: Make this guy.
9-10: Connect it onto the conjoined panels.
11-12: Make this awesome bit.
13-14: Connect it.
15-16: Build this track piece.
17-18: Make this track piece too.
19-20: Add in the track pieces like so.
21-23: Connect it up to the main machine.

Step 12: Track Piece #9

Its fine to be building track #9.

1-2: Build this panel.
3-6: Build this one too.
7-8: Connect the two.
9: Build this little guy.
10: Add him on to what you just made.
11-13: Build this tracking piece.
14-15: Put the tracking on top. Make sure to put it on the right way around, its easy to put it on back-to-front.
16: Make this little track bit.
17-18: Put it in the middle of the structure that you've made.
19-21: Attach the whole shebang to the main machine. Sorry these photos aren't the best.


Step 13: Track Piece #10

Sorry about the incredible lameness of the joke in the preceding steps...

1: Build this guy.
2-3: Make this panel.
4: Attach the two.
5: Make this little thing.
6: And this one too.
7: Connect the two.
8-9: Put it onto the frame you built before.
10: Make this bit.
11: Build this part too.
12: Connect the bits from 10 and 11.
13: Build this panel.
14-15: Make this panel as well.
16: Connect the two - be sure to connect them the right way up!
17-18: Combine the bit you made in photos 10-11 with the part you made in photo 16.
19-21: Now connect the two main structures that you've built in this step.
22: Build these two tracking pieces - I trust by now that you don't need more close-ups.
23: Make this track bit too.
24: Build this one as well.
25-26: Smack that track on top of your structure. Make sure they go in all the right spots.
27-29: Add this bit onto your growing ball machine.
30: Your overhead view should now look like this.

Right on! Let's continue.

Step 14: Track Piece #11

Let me try one more joke.

Why did the golfer bring two pairs of pants to the golf course?

1-2: Build this panel.
3-4: Make this one as well.
5: Connect them.
6: Make this panel.
7-8: Construct this thing as well.
9-10 Join the two sides.
11-12: Connect the two bits that you've made thus far.
13: Make this funky piece.
14: Make this equally weird thing.
15-17: Join the two.
18: Make this track piece.
19: Put it into the part you made in photos 13-17.
20-21: Now connect it to the structure you made from photos 1 through 12.
22-23: Build this dropping track piece, if you need more photos, see step 7, the dropping track piece in that step is identical.
24: Add it onto your frame above the single track piece.
25: Make this tracking piece.
26-27: Build this tracking piece too.
28-29: Put thems tracking parts on top of the structure that you've built in this step.
30-32: Connect the whole thing to your main machine as shown.

Well done :-D

Step 15: Track Piece #12


I'm very sorry.

1: Build this twiggy thing.
2: Make this as well.
3: Combine the two.
4: Build these two parts, they are identical.
5-6: Attach them onto the bit you made before.
7: Build these three tracking pieces.
8-9: Put them on your frame like so.
10-12: Connect them to the main machine.
13: Your overhead should now look like this.

I like short steps like these.

Step 16: Track Piece #13

Another nice short step.

1-2: Build this funky bit.
3: Make this panel.
4-5: Connect the two.
6: Build this tracking piece.
7: Add it on top.
8-10: Add it onto the ball machine. Its a bit of a weird connection. Be sure that you've got it right. It should float around three blue rod lengths above the ground.

Step 17: Track Piece #14

But of a weird step here. Pay close attention.

1: Build this.
2: Make this too.
3-4: Connect the two.
5-6: Build this track piece.
7: Put it on top of the bit made in photos 1-4.
8-10: Build this half-tower thing.
11-12: Build this other half.
13-14: Connect the two together.
15: Make this tracking piece.
16: Add it on top of that tower.
17-19: Connect the bit made from photos 1-7 with the tower thing made from 8-16.
20-25: Connection madness! Attach the part you made in this step to your ball machine. There are piles of connections here. Connect if it looks like it should connect, that's my motto.

Great! Onward.

Step 18: Track Piece #15

The shortest step of this entire instructable, I think.

1: Build this part.
2: Make this one too.
3: Connect the two.
4: Build this tracking piece.
5: Slap it on top.
6-7: Add onto the main machine.

Moving on...

Step 19: Track Piece #16

Another reasonably straightforward step. Yay!

1: Build this piece.
2: Make this one too.
3-4: Connect the two.
5: Build this tracking piece.
6: Put said tracking on top of the little frame you made.
7: Make this piece.
8-9: This one too.
10-11: Combine the two bits in photos 7-9.
12: Build this very familiar track piece.
13: Put it on the bit you build in photos 7-11. It only connects in one spot.
14-15: Now put your two main pieces together like so.
16-19: Connect the whole dang thing! It should be pretty straightforward.


Step 20: Track Piece #17

One more attempt at a joke.

What makes the Titanic and the Toronto Maple Leafs so similar?

1-3: Build this big 'ol panel.
4-6: Build its counterpart.
7-9: Connect the two.
10-11: Build this dropping track piece. You should be able to build this one without much instruction by now.
12: Add it on on top like so.
13-16: Add it onto the main machine.

No sweat.

Step 21: Track Piece #18

They both look great until they hit the ice!

1-2: Build this tall panel.
3-5: Make this similar panel.
6-7: Connect the two panels.
8-9: Build these two parts.
10-11: Build this bent thing.
12-13: Connect the bent thing to the two parts made in photos 8-9.
14-15: Now add the bent part to the tall chunk you made at the start of this step.
16: Make this tracking piece.
17: Build these two as well.
18-19: Put the tracking pieces in on top.
20-23: Attach to the main machine! All connections should be straightforward.


Step 22: Track Piece #19

Another nice and simple step.

1: Build these three pieces, they are all identical.
2: Build this little piece.
3: Connect it like so to one of the pieces made in photo 1.
4: Make this similar bit.
5: Connect it to the part made in photo 3.
6-7: Now, make this bent part.
8: Connect it as shown.
9-10: Add on the other two bits made in photo 1 as shown.
11: Make this part.
12-13: Add it in the middle of the part you've been building.
14: Make these three tracking pieces.
15: Build this longer track piece as well.
16-17: Add the tracking pieces in on top.
18-20: Add it on the bottom of your machine.

Almost done!

Step 23: Track Piece #20

An even shorter step. Go!

1: Build this panel.
2: This one too.
3-4: Connect the two.
5: Make this little stubby part.
6: Build this little one too.
7: Combine the two little parts.
8-9: Now add the part made in photos 5-7 with the ones made in 1-4.
10: Make this tracking piece.
11: Build this longer track piece.
12: Put those two tracking pieces in on top.
13-15: Add it on to the main machine.

Only two more track pieces to go!

Step 24: Track Piece #21

This is a long, funky step. Sorry about that.

1: Make this piece.
2-3: Make this odd bit.
4-5: Make this similar odd bit.
6: Combine the odd bits.
7: Now add on that part from photo 1. Put this chunk aside for a moment.
8: Make this tracking piece.
9: Add it in on top.
10: Make this part.
11-12: Make this bendy piece.
13: Combine the parts from photos 10-12.
14: Build two more of the basic track pieces.
15: Put them in on top.
16: Build this incredible little part.
17: Connect it onto the blue rods of the tracking piece as shown.
18-19: Grab that chunk you made in photos 1-7 and connect it to the piece you made in photos 8-17. Now put this larger piece aside for a moment. This is where things begin to get really weird.
20-21: Build this bendy bit.
22-23: Now make this other part.
24: Combine the parts in photos 20-23.
25: Make this little guy.
26-27: Add it onto the part you just made.
28: Make another little tracking piece.
29: Add it on on top like so.
30-32: Now add it onto the end of the part made in photos 20-29.
33-36: Now take the larger piece you put aside in photo 19, and add it onto what you just made. It should now look like this.
37-41: Add it in on top of the whole machine! There are numerous connection points here, be sure to get them all!

Wohoo! One more to go!

Step 25: Track Piece #22

Last one!

1-2: Build this tracking piece. If you need more photos refer to step 7, its identical to the track piece in there.
3: Make side panels.
4-5: Add the two panels onto the sides of the track piece.
6: Build these two parts.
7-9: Now make this bendy bit.
10-11: Attach the two parts from photo 6 to the bendy bit.
12: Now attach the tracking piece to the part you just made.
13: Build this two tracking pieces.
14: Add them in on top.
15-16: Build this tracking piece that has some other stuff attached.
17: Add it onto the end of the chunk that you've made.
18-24: Slap it in on top of the main machine.

Step 26: Adding the Tubing

Here we go!

You'll need two lengths of rollercoaster tubing of at least 32½ feet. The two lengths can be made up of smaller pieces spliced together if need be.

1: Start on the lift. It's the best place to splice two pieces of tubing together. I did it about halfway up, but it doesn't matter very much where exactly you start.

Step 27: Modifications

After I took my ball machine apart and put it all back together for the instructions, I made a few mods to my machine that may make yours work better. They are optional, though if any balls are falling off the track, you should probably make these modifications.

1-3: This is on the second level from the top. I bumped up the outer side, as the ball was sliding around more than I liked.
4: This was just a mistake I made in the instructions. There was a blue rod coming down from where the yellow connector is now. It obstructs the path of the ball, so it obviously has to go.
5: Here I dropped the first blue rod length section of the track after the turn. It stops the ball from bobbling around as it heads into the next turn.
6: Move over the blue rod in the box here. The ball sometimes clips it on the way by otherwise.
7: Not so much a mod as a reminder to pull of the railings as high as they will go. It helps the lift work properly.
8: This is thoroughly optional. As you might have noticed, the red connectors on the lift chain come very close to the floor. If you are running your ball machine on a low carpet or hard floor, it wont be a problem, but when it is run on a big fluffy carpet, the red rods can sometimes snag a bit. To fix this, just put a little strip of scotch tape where the red connectors hit the ground to keep things running smoothly.

Thats it! If you have any other mods, please tell me and post pictures! If I think they are good mods I will add them to this page.

Step 28: Add on Some Spindley Legs?

This was just a weird afterthought. The idea was just to get the machine off the ground so that it would be easier to see... These legs put it at about waist height. Its a pretty cool idea, but if you want to try it, don't use the design I used, it sucks.

This is also cool because you can lie down under the ball machine and watch it from there. Its pretty sweet.

Be sure to post photos if you design some legs yourself!

Step 29: Finished!

Congratulations! If you made it this far, you probably have built the machine, so great work, and THANK YOU! Its an honor to have people build my creations, and I get a kick out of it every time.

If you have built this ball machine, I want to know! Also, if you do complete it, post a photo of it and I will upload it to this page.

If you have any comments, questions or whatever, please drop me a line!

Thanks again,


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