3 Simple Ways to
Share What You Make

With Instructables you can share what you make with the world — and tap into an ever-growing community of creative experts.

PhotosPhotos

Share one or more photos of a project, recipe, or whatever you've made, quickly and easily.

Get Started

Learn more & Get Tips

Step by StepStep-By-Step

Share your step-by-step photos with text instructions of what you made so others can do it too!

Get Started

Learn more & Get Tips

VideoVideo

Share your how-to video. You'll need your embed code from a video site such as YouTube.

Get Started

Learn more & Get Tips

View Contest Results

This was a
Third Prize Winner!

Print PDF

Favorite

Coin Operated Knex Gum Ball Machine!

last photo ←

I BUILT THIS FOR THE I MADE IT CONTEST!! As you can see i posted it the day of the deadline :)

This is my new creation! It is coin operated and designed for quarters.
If you drop in a penny, nickle or dime, it will just take your coin. :)
For every quarter, one gumball is dispensed.

Please read:
I also built lock and key mechanism for safely storing the collected change.
Unfortunately I didn't have enough knex to finish the rest of it :((
I ran out of green rods and 3D connectors.

So i am left with a random lock and key system with no way to attach it to the bottom of the machine.
I Hope the Coin Operated Gumball machine alone is enough :)

254 comments

1-40 of 254

Dec 27, 2011. 4:19 PM

PotatoCoffee says:

Wow!

Dec 4, 2011. 1:14 PMPuddock says:

I think this is fantastic!

Sep 24, 2011. 11:23 PMSnosageman99 says:

Can u post the lock or is it already somewhere on the site?

Aug 28, 2011. 5:56 AMnhurtado2 says:

Thats totally false. In the other video you can see better that you don't introduce the quarter. It is just a mechanism that makes that always you turnthat thing, a gumball cames out.

Aug 25, 2011. 6:22 AMnhurtado2 says:

you NEED to make instructions

Aug 19, 2011. 11:54 PMsb18281 says:

couldn't you just make a replica key out of your own knex?

Aug 15, 2011. 9:39 AMK'nex gun builder says:

You're awesome! I have never seen anything as cool and complicated as that! Great job dude.

Aug 14, 2011. 10:20 PMg20617 says:

cool do a how to

Aug 8, 2011. 8:58 PMJoedidley says:

Please post coin mechanism

Aug 4, 2011. 3:54 PM

NE patsrock says:

by the wat if you look at my user pic im a kid to11

Aug 4, 2011. 3:54 PM

NE patsrock says:

dude ur awesome!!!! i never thought u were a kid im gunna follow u!!!

May 1, 2011. 11:54 AMTheDunkis says:

We have a gumball dispenser before we have a K'nex dispenser. -_-
Good job, though. Now, do you suppose you could make one large dispenser for all the different connectors and rods? It'd be kind of strange to store K'nex in your K'nex but I've been waiting for someone to try this out for as long as I can remember.
And you don't by chance airsoft, do you? I've also been looking for someone to build a decent speedloader for even longer.

Jul 9, 2011. 10:06 PMapples!!!!! says:

What's funny is the speedloader is the first thing I thought of when I got onto this site lol. Maybe I should try it out >.>

Jul 10, 2011. 9:24 AMTheDunkis says:

I still have yet to see one that works very well and stores a decent amount of BBs. If you could finally accomplish it, I'd be in your debt.

Jul 11, 2011. 1:23 PMapples!!!!! says:

Here you go. It's basic, as I did it quickly, but it gets the point across as well as anything made of K'nex will for such purposes. I even gave it your favorite feature- a block trigger, just for you :D if you want a better look then I'll post a photo 'ible, but it's kinda lame so...yeah. Stores like...75-100 or so, but can be expanded to hold like 500 lol.

Jul 11, 2011. 4:12 PMTheDunkis says:

So it's more like a dispenser than a speedloader? Neat, but I need something to force bbs into a magazine rapidly that feeds reliably. That's the tricky part. I made one some time ago that had the loading and feeding of BBs down, but it wasn't easy to align it with the magazine so it just spat them out really. I would've improved it but it didn't hold that many either so I was hoping someone had a better design. However, I think you're onto something. Maybe make a pressure sensitive blocker that you force bbs through.

Jul 11, 2011. 5:16 PMapples!!!!! says:

Derp, they need force? Well then, lol. The magazine on mine lets you draw the spring down and pour them in, so I kinda went off of that >.> back to the drawing board, I suppose. And you see, the alignment problem is unavoidable with knex for the most part, because the smallest thing you're going to put a bb through is a grey clip, which doesn't exactly align properly.

Jul 11, 2011. 6:25 PMTheDunkis says:

Well if they didn't, I'd just use a bottle with a spout to pour them in... The kind of magazines I'm concerned about are the ones that require loading tubes with a rod to ram them in. And I realize you can't properly align them with the pieces there are, I'm thinking I could probably tape a pen tube section onto the end of one to fix that. Now I'm just looking for the most effective storage possible and a reliable loading system.

Jul 19, 2011. 10:07 PMapples!!!!! says:

Here you go. It's crude, the pressure system is scrapped because it didn't work well when tested with speedloading a clip and it can get a bit tough to pump sometimes, but it's like 20 pieces and holds around 65 BB's(more if you're willing to shake harder and jam the loader a lot). It's a good start, it can be expanded to red rod size and beats the hell out of everything else on the site, in my opinion. I could post it if you'd like. It needs a bit of work, but it's a foundation nonetheless.

Jul 15, 2011. 1:41 PMapples!!!!! says:

Oops, forgot to respond. I now realize that whole pushing system, and I'm very near done. I'm trying to make it as reliable as possible while keeping space open in it. It's got the pressure release as well, so this is actually very likely. As for the storage, I'd recommend what I made- it holds a large amount while using very few pieces and being quite sturdy.

Jul 10, 2011. 10:55 AMapples!!!!! says:

I used to airsoft, and I haven't quite started a new project yet so I guess I'll go for it right now. I'm really bored lol.

May 27, 2011. 1:45 PMjamesdude says:

I would probably attempt the knex dispenser idea if I had enough pieces... why don't you try TD?

May 27, 2011. 2:33 PMTheDunkis says:

Because I don't have the pieces nor the patience.

Jul 3, 2011. 1:21 PMnebih says:

i have one set of knex and they are for a knex coaster so i have the least ammout considering i have only 1 white connecter...

May 30, 2011. 8:44 AMjamesdude says:

Meh, you have more pieces than me at least... I still think you should try.

May 1, 2011. 7:11 PM

KnexFreek (author) says:

haha thanks. uhm well would the knex dispenser like take coins or do you mean you just turn a handle for a piece. i could do that but it would be alot of work to design the mech for each different piece. cause each piece is a different size and shape. also i dont, but i might work on it. i know how they work.

Jul 10, 2011. 9:28 AMTheDunkis says:

Sorry, very late reply, didn't notice that I didn't reply until now, here's my idea, just make like a magazine for connectors, something that fits them all horizontal so that the bottom piece will be laying flat for sure. Then use a button or lever to push the piece out kind of like a really weak semi auto gun. For rods, you could do the same but use a hopper. The result will probably be something really big, but if you could dress it up so it look like one clean device instead of a bunch of random containers all attached to each others, that'd be cool. Also, maybe if you want to make it cylindrical and give it the ability to rotate? That might save some space and add extra cool factor. If you want to make a separate one for rods and another one for connectors, that's understandable.

May 16, 2011. 6:01 AMagent harmsy says:

Maybe press a button and a set quantity comes out? Might have to store them in seperate tubes (combine with that connector sorter?)

Jul 16, 2011. 11:06 PM!KnexMaster! says:

PLEASE PUT INSTRUCTIONS!!!
i will be very greatful

Jul 13, 2011. 3:30 PMknextremist says:

post!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!please!!!!!!!!!!!!!!!!!!!!!!!!!!!! I will subscribe if you post!!!!!!!!!!!!!!!!!!!

Jul 9, 2011. 10:05 PMapples!!!!! says:

"Only this key will open the lock"

Or a hammer :) but seriously, nice job with this. I'm thinking of making a much smaller-scale version sometime, because it's a great idea! The coin recognition is particularly impressive.

Jun 23, 2011. 5:17 PMSketch98 says:

NOOOOOO, now I have to lose all of my quarters to your monstrous machine. Why couldn't you just make it so that someone could just reach in and grab gum balls, oh wait...

Jun 21, 2011. 9:10 AMbumboozer says:

Amazing!!!!!!!!!!! Plz post

Jun 4, 2011. 12:20 PMjordanguy123 says:

PLEASE PLEASE TELL ME HOW TO MAKE THIS

Jun 3, 2011. 2:25 PMJoJoJo00 says:

P.S. By the way, do you yoyo? jw

Jun 3, 2011. 2:24 PMJoJoJo00 says:

Sooooooooooooooooooooooo...PLEASE POST!!!

Apr 28, 2011. 8:03 AM

Hiyadudez says:

No collab anymore then? :-(

Apr 28, 2011. 12:53 PM

KnexFreek (author) says:

No we are definitely still doing the collab. I always post a slideshow before i post, then i post the ible with improvements. In this case, it will have a locking safe it will stand 3-4 feet tall and have a spiral gumball drop to the bottom :)

i hope you have the pieces!

We should start soon !!!!