Motorized Marble Roller Coaster




About: I got an old sewing machine when I was just a kid, and I've been hooked on making stuff ever since. My name is Sam and I'm a community manager here at Instructables.

This is a roller coaster for marbles. It's made from lots of cardboard and hot glue, some stuff out of an old broken printer, and a few other odds and ends I had laying around.

I played around with cardboard, tape, glue and marbles a lot as a kid, making tracks and ramps and such just for fun.

I had been wanting to make one of these for years, just to see what I could come up with now that I'm a little older. The main thing I'd been wondering about was how I could get the marbles back to the top with some sort of mechanism made from simple, available items.

The whole thing turned out pretty well, and surprisingly, the motor/conveyor belt system I came up with works perfectly, although the initial version was really fast (see the video in step 6).

I made a few changes to slow down the conveyor, and the final painted version is shown here.

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Step 1: Supplies

I gathered up quite a bit of craft cardboard for this project, along with a few old boxes from the trash.

I used lots hot glue, along with some wood glue and white glue in a few places.

Step 2: Base

The base is made out of MDF. It is 20 inches by 40 inches, and about 4 inches tall.

Step 3: Original Motor Assembly

(This was quite the hack job, but it worked.)

The electric motor is out of an old printer. The drive is made from a section of cardboard tube, along with MDF glued to the inside, and rubber bands placed on the outside to give traction to the conveyor belt.

The motor was hot glued directly to the base, and the geared end of the motor was pressed against a rubber band on the conveyor drive. The power comes from four double-A batteries in a holder from Radio Shack.

Step 4: Conveyor Belt

The conveyor belt is made from 72 inches of nylon webbing, with 3/4 nails placed through it every 3 inches. The nails are glued to small folded pieces of thin white cardboard, which keeps the nails standing up straight when they are pushing against a marble.

A cardboard guiding track was built around the conveyor belt. This V shaped track keeps the balls centered on the belt. A thin piece of wood was built into the track under the belt which keeps the belt from sagging.

I added little triangular pieces of cardboard to the front of each nail and "flag" which keep the marbles in place on the track while they are being pushed along.

Step 5: Track

I used strips of corrugated cardboard that were glued to form T beams as the main supports for the track. Each section of track is made from two corresponding pieces of single-ply cardboard that form a V-shape. Small strips of cardstock-like cardboard were used to glue the track strips together. Please examine the photos for detail.

I made up the layout of the track as I went along. It took a lot of trial and error to create all the various sections of track that curve, dip, rise, etc. The trick is to build and test with a marble as you go, and if it works, great--if not, take it apart and try something else.

If you're interested in making a marble coaster but are somewhat scared by the complexity of my project, take a look at these instructions for building simple marble tracks (shared by user Covo).

Step 6: Video of Original Version

Check out the video. The lift on this was crazy-fast, but pretty cool. Note how the ball is actually thrown from the lift and hits the track with quite a bit of speed:

Step 7: Upgrades!

I agreed with a few of the first commenters that the lift was way too fast, as seen in the first video, and that this definitely needed a paint job.

I dug around for more parts I had kept from the old printer and found a small rubber belt along with a bunch of gears. These were put to use to slow the lift down to a nice, roller coaster-appropriate pace.

I modified the cardboard drive cog to accept the new motor belt, and added a tower to house the motor, gears, and battery pack.

Because of the slower lift, I had to make some adjustments to the positioning of the upper portion of the track which receives the ball off of the lift. This slowed down the track somewhat, so I also had to switch to using steelies (heavier metal marbles).

Prior to painting, the tower looked a lot like a prison yard guard tower. That was unintentional.

Step 8: And Another Video

Here is the painted, completed version in action:

As a parting note, I have a couple of balls out of old computer mice--they are heavy and rubber coated. They are silent as they go down the track, and very lively. My track wasn't built with these heavier balls in mind, so they tend to fly right off in a couple of spots.

If I ever build one of these again, I'm going to build it to be used with an old mouse ball, and I would recommend anyone interested in building one of these try them out. They create a really cool effect.

Let me know what you think!
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    131 Discussions


    10 years ago on Step 5

    So you didn't actually bend the cardboard to make the track, you have created the tracks by joining two stips of cardboard. Right? Also, some other question, how do you make the cardboard so "glossy" as it appears in the video? Is it just the paint? (spray paint?) Thanks! It's wonderful, I've been dreaming for a long time to make something like that but I hadn't got to it... now it's time! :)

    1 reply

    Reply 10 years ago on Step 5

    Yes--the track is made from two adjacent pieces of cardboard.

    Each side of the track is about 3/4 inch tall. I would draw out each new section of track on a sheet of cardboard, cut it out, and then match it up to an existing piece to see if it would fit on the track the way I wanted. These were like "trial" pieces. If the new piece worked well, and took the ball where I wanted it to go, I'd add the new piece permanently to the track, thus extending the track little by little.

    If the new trial pieces didn't fit, which was the case most of the time, at least I could see specifically what shape the new pieces needed to be. Many times I would just try something--knowing that it probably wasn't going to work--but that it would show me what would.

    Certain sections (like the loop) were completely made off of the the base, and then added as a finished unit.

    This project took lots of trial and error, practice, and patience!

    As for the paint, I brush painted everything with basic acrylic craft paints. The paint seemed to slow down the track somewhat, so I gave it a coat of lacquer spray, which helped speed things up, and gave it that glossy look you see.


    3 years ago

    how do you hold up the track


    Reply 3 years ago

    You should be able to find it at any home improvement or hardware store, but also at most large grocery stores as well.


    3 years ago

    How long did this take to make it?


    Reply 4 years ago on Introduction

    The motor was just pulled from an old printer. I mounted it to a couple brackets and used some of the belts out the printer as well. This was several years ago, and I no longer have it... so I can't really tell any more details than that. :)


    4 years ago

    Do u know wat exacally what i would need to make the roller coaster and how many peices of each i would need


    4 years ago

    Is it just me or did the marble skip the loop-the-loop?

    How did you make your track so smooth? Because when you bend cardboard it usually gets all bumpy and rigid? Did you cut a certain shape to make the turns? And how did you make the loop with it keeping its smoothness?

    1 reply

    I used thin non-corrugated cardboard--the kind of stuff cereal boxes are made out of. So it was more like thick paper, which you can bend more easily than the corrugated box-type cardboard.


    Reply 5 years ago on Step 5

    Hey, thanks!

    I'm actually working on another marble coaster right now. Only it will be all wood, and from a single 2 by 4!

    . . . We'll see if I ever get it done though, as it's proven quite a challenge thus far!


    Reply 5 years ago on Step 5

    Whoa, sounds like a serious escalation. I hope you'll post it up to this thread somehow so I get a notification to come check it out. I love these rube goldberg roller coaster mouse trap thingies.


    7 years ago on Introduction

    This is awesome. Great work - my son used to watch videos on youtube (from Japan) of rolling ball machines all the time. Love them all!


    7 years ago on Introduction

    How much does it cost for all the track materials?