Marble Clock




About: Try again. Fail again. Fail better

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Marble Clock is a 3D printed rolling ball clock that tells the time by the location of marbles/balls. It consists of 3 main rails, where,

  • The 5-minute rail with 1-minute intervals
  • The 60-minute rail with 5-minute intervals
  • The 12-hour rail with 1-hour intervals

add up and tell the time.


In the first step, I will give you a little bit of history of rolling ball clocks and ball clocks in general. Next, I will explain the Idea behind this project. Then I will give you an insight into the design process of this clock, so you'll be able to design your own clock. I'll give you a 3d print guide so you can easily print the required pieces and arrange them. After giving you a step by step assembly guide and show you how to sync your clock, I'll end the instructable with a troubleshooting guide. So, if you encounter any problems during your build you can solve them easily.

The purpose of this instructable is not just to give you a cookbook. I'll show you the way I built this project and provide you with open-ended questions, so you can add your own ideas, and take this project even further. Many parts I've designed are not connected. This way you can change the design to your own liking and then glue them together.

I strongly encourage you to share your build when it's done!

Let's get started.

Step 1: A Short History of Marble Clocks

This instructable is based on the design called "rolling ball clock" that was invented by Harley Mayenschein in the 1970s. He patented his invention and started a company which began to manufacture these clocks from solid hardwoods in the 1980s.[1]

The original rolling ball clock had 3 main rails, 2 for minutes and 1 for the hour. by adding the two rails one can get the total minute. This way the time was shown.[1]

There were many varieties of these clocks ... for example the kineticlock which had 10 minutes intervals instead of 4, or the Chronomeans Clock which was built with anodized aluminium.
Other rolling ball clock varieties:



Further Reading:

Step 2: The Idea

I've been a long time fan of ball clocks. I've seen one when I was a kid in a novelty store. And I just stood there watching it endlessly. The movement of the balls with time was magic to me. After I heard about the clock contest on Instructables. It gave me the Idea to try to design and build a ball clock from scratch. So I started to sketch on paper.

What I wanted to do was to design a different lifting mechanism instead of the traditional rotating scoop type design. So then it hit me. I was going to use a rotary to linear motion mechanism so while the mechanism was rotated by a motor the ball would be moving in a line, up and down. Creating a little illusion.

The rails were mostly inspired from other ball clocks but I had an idea to create a bell mechanism so everytime one hour passes there would be a sound. Unfortunately, I could not build this into the project.

Step 3: Tools & Parts

Note: these are the Tools&Parts I had available. You can use any other part for your needs.



3D Printed Parts :

all parts are on step 5 I recommend you to read read step5 before printing them.

Step 4: Design Process

You can skip this step if you just want to print the project. This step is for people who want to design their own ball clocks or want to add new features to this project. It gives an insight on how the ball rails were designed in Fusion 360.

If you are new to the Fusion 360 environment I suggest you take a look at a few tutorials.
You can enroll in this class:

also, this youtube series gives a good beginner tutorial:

I suggest you to read this step after you've seen the tutorials.

Details on the design process are noted on the images.

Base Structure & Rails

The base structure is basically 6 rails holding 4 rods. The rods(8mmx8mm) were designed to be sturdy. They are held by bolts to a wood plate. The rails were inspired by the original rolling ball clock. But the dimensions are different due to different ball sizes and weight distribution.


The elevator design was inspired by this mechanism. User mgg942 used this design and created a rotary to linear drive on Thingiverse . I tweaked and re-designed this to create an elevator mechanism.

Step 5: 3D Print

There are two seperate .zip files you can download.

The 3d folder contains all the parts for the clock separately.

The contains 5 sets. each set is designed for a 25x25cm print area.

If you have a large print area you can print these like I arranged them in sets. Or you can print them separately.

I suggest you to finish printing before the assembly of any pieces. It's much easier if you lay them on a table in an arrangement. Like a LEGO set.

Each part is given a number and a letter. these will be useful while following the building instructions next step.

Step 6: Base Assembly

you can use the pdf template to drill holes on the wood.

Parts used in this step:

  • [3d printed] 1a-3f (28 parts)
  • 5 x 40mm M3 bolts & nuts
  • 6 x 30mm M3 bolts & nuts
  • 3 x 15mm M3 bolts & nuts
  • 6 x 10mm M3 bolts & nuts
  • 10 x 6mm M3 bolts & nuts
  • 4 x (3mm*6mm*2.5mm) ball bearing

Tools used:

  • Tack-it
  • philips head screwdriver
  • pliers

Estimated Time:

  • 15-20 minutes

Note: Assembly instructions are noted on the images.

Step 7: Center of Gravity

This is the most important part of this project. I did not design the rail pieces connected to the joints. This way everyone can adjust them to their needs. The rails and the connectors under them are not attached. You have to figure out the center of gravity and glue it when you are certain. Let's begin,

The 5min rail:

Slowly put 4 balls on the minute rail. And position the connector piece accordingly so it doesn't tip over. It should tip over when the 5th ball comes. This takes a bit of time to adjust. When you're satisfied go to the 15min rail.

The 15min rail:

Slowly put 11 balls on the rail. again it shouldn't tip over while 11 balls are on it. When the 12th ball arrives it should tip over.

The Hour rail:

This is the same as the 15min rail. wherever you glued the connector on the 15min rail you can glue it on the same place on the hour rail.

Lastly, to test them all at once put 11 balls on the hour and 15min rails and 4 balls on the 5 min rail. then drop one ball to the 5 min rail. They all should go smoothly and leave the rails

Step 8: Elevator Assembly

Parts used in this step:

  • [3d printed] 4a-5d (9 parts)
  • 1 x 25byj-48 Stepper
  • 4 x (3mm*6mm*2.5mm) ball bearing
  • 1 x (F6-14M 6mm x 14mm x 5mm) Thrust Bearing
  • 2 x 10mm M3 Bolts & Nuts
  • 2 x 25mm M3 Bolts & Nuts
  • 2 x 6mm M3 Bolts & Nuts
  • 4 x 40mm M3 Bolts & Nuts

Tools used:

  • Tack-it
  • philips head screwdriver
  • pliers

Estimated Time:

5-10 minutes

Note: Assembly instructions are noted on the images.

Step 9: Driving the Motor & Timing

How to drive the motor

To drive the 28byj-48 stepper motor with a constant speed I've used an Arduino Uno with the AccelStepper library. you can download the library here . If you don't have experience with Arduino or don't know how to install libraries you can check this site.

Connect the pins on the stepper motor to the Arduino like this:


  • IN1 ----> 2
  • IN2 ----> 3
  • IN3 ----> 4
  • IN4 ----> 5

After uploading the code you are good to go!


The most important thing about a clock is precision. We want this clock to be as precise as any other wall clock/ watch so it works without any error. To do this we have to change the speed of the motor so the elevator completes 1 revolution in 60 seconds precisely.

Now get a stopwatch in your hand and run the motor. Start the stopwatch when the elevator gear crosses a specified point. And stop your watch when it crosses the point again. Take a note at the time. now let's calculate the required speed

T = time on your stopwatch

t = 60s (time you want it to complete 1 revolution)

M = old motor speed("stepper.setSpeed()" in code)

m = new motor speed("stepper.setSpeed()" in code)

new motor speed(m) =(T*M) / t

Insert this into the code and check your stopwatch again, repeat this until you are satisfied with the result

Step 10: First Test

You're done with the build now it's time to test this clock!

Check your watch and put the balls according to the time. And start the motor when you are ready. It's really fun to watch time go by with this clock. Go and put yourself some tea and enjoy the sound off balls clicking. Now while doing that you should check a few things to be sure that this clock can run for 7/24 straight.

Things to look for:

  • Can the elevator bring a ball without dropping it each minute?
  • Are balls not getting stuck on the rails after 2-3 hours?
  • Is the clock on time after several hours?

If your answer is no for at least one of those questions, you can check the Troubleshooting step!

If your answer is yes, then congratulations you've built a precise ball clock!

Step 11: Troubleshooting

- Balls are not moving easily on the rails

Sometimes filament residue blocks the balls. use a sandpaper to sand the pieces.

- The motor is stopping after a few hours.

Try to connect external power to the motor.

-the balls are falling even though I set them not to fall

The surface the clock is on can effect this try to change the location of the clock

-The clock is not on time

Repeat the timing step as much as you can until you are satisfied

Step 12: What's Next

There are lots of things that can be improved on this clock. Here are a few that I have in mind.

  • Adding an am-pm rail.
  • Adding a bell so it makes a sound every hour.
  • Creating a more stylish ball descent system. instead of the ball tower that just drops the balls.
  • Make a bigger version with different kind of balls

I hope you enjoyed this instructable.

If you have any questions ask away! & tell me about your build!

Clocks Contest

First Prize in the
Clocks Contest

6 People Made This Project!


  • Classroom Science Contest

    Classroom Science Contest
  • Beauty Tips Contest

    Beauty Tips Contest
  • Sensors Contest

    Sensors Contest

86 Discussions


I am trying to assemble the gear assembly, but from the pictures do not understand how to connect the gear which picks up the ball. Can anyone assist me or have pictures/video tutorial? Any help is appreciated.

1 reply

Reply 21 days ago

I printed 1 mm and 2 mm thick flakes with the same radius at the center space of the gear and filled the distance with this flakes between the gears. I used bearings too. But because i completed the project, i can't send photos for now.


10 months ago

Here is where I'm done, functional, not yet finished. Rails must be assembled at first. I've made a stronger ladder by doubling posts thickness. Base plate must be rigid to preserve geometry, I chose 5 mils MDF instead of acryl. Also, I did not choose the bearing version for swivel but I prefered a 4mm diam brass tube on 3mm screw all along rail width (12mm), a nearly no play assy ( bushing) much easier to align. At second step, the reception part must be built with the same logic of stiffness. For elevator, I've printed gears out of ABS cause I don't believe in rotating mechanical parts made of PLA. When ready, I'll make a longrun for reliability check. At last, motor speed, synchro and precision will be matter of software but peanuts in regards to that mechanical system made from printed plastics....

5 replies

Reply 9 months ago

Your modifications seem to solve a lot of problems I am having with this build. Would you be able to attach stl files for the modified pieces? Also could you send a link for the exact type of bushings you used? A dxf file or exact dimensions for the holes in the baseplate would also be very helpful.


Reply 9 months ago

My prototype is fully functional but require some more modification. Unfortunately I've no time to work on this project for the moment. Here is a link to the sketchup files for parts I've modified.

This is not fisnished (a mess ;-)) but could be a starting point for your own design.

About the bushing, this is part I named pivot. In this part I've inserted a piece of 4mm diameter brass tube. It rotates on 3mm screw with very few play. Major improvements are: 2 pieces storage rail, bushing pivots, one piece elevator wheels, stiffer minutes/hour rails ladder.

Another major problem is the motor becoming so hot. I have to look for another type and redesign the elevator accordingly.


Reply 7 weeks ago

For motor heating problem, i advice using a 5 or 6 V power supply.
At 12 V it is incredible hot.


Reply 9 months ago

Thanks for sharing your design Vincent, it will be of great help.


Reply 9 months ago

Well, to be honest, that looks more stable than my build :D, Thanks for sharing! great work.


Question 8 weeks ago

I am not experienced on the ardinuio circuit. Do I need to buy a 5 volt power supply too to make the clock work?


3 months ago

Good day, Thanks for the cool clock - I worked with my 5yr old to build one, the first one didn't go well, but with some tweaks the second one went well, he wanted one made in all the different colour filament that we had. I ended up creating my own ramp as the three piece one wasn't working for us, there just wasn't enough drop for the length and the balls kept getting hung up on it, we created posts to hold the ramp that concealed the screws. Also changed the mount for the large rotating gear off the arm as the other didn't seem stable enough. The large stationary gear was way to "wobbly" so we made some mounts that went off the top of the two towers which helped with the wobble of the large gear and the rail tower that just had as single tower. Frequently the ball would fall out of the "cup" on the large gear about 1 1/2" from the top rail so I created a guide - just a piece that hangs off the top rail so that the ball can't fall out. Made some mounts for the top rail as well. We used Arduino nano's that we could just solder directly to the stepper driver and made a little box to hold them. Fun project. On the second one we only printed the rails with 15% infill and this messed up our balance more than expected - We just drilled a hold in the end of the rail and put an M3 screw in the end - adjusted length as needed to get the balance correct.

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1 reply

Reply 3 months ago

Hi Rob, nice job! Could you please share the 3d parts you design?


Tip 3 months ago

He realizado el reloj escalando todo al 0.93 ya que mi impresora es una prusa normal de 22x22.
y no me cabe al 100x100. Las bolas son de 10 mm. De rodamientos de AliExpress y funciona de maravilla.
saludos desde España.
Rafael Morales


Question 3 months ago on Step 9

Thank you for your Marble Clock.
It is very aesthetic to see. I wanted to make it immediately.
But I have a problem understanding for its editing.
The attached photo shows my request for help.
Thanks for your help


Question 4 months ago on Step 5

Hi Brian, thank you for this magnificent design. He decided to start manufacturing it. I have no experience with 3d printing. I have to buy from a company that does that job. I would appreciate if you can tell me what type of material to use: filament ABS or PLA. In addition, how many millimeters of deposition material of the printer or some other parameters that you know can indicate to obtain a good result (compatible with the price and the necessary average quality) after printing. I hope your repply thanks a lot. Carlos.

Question 5 months ago

could you post some side and rear shots?, can't see how the ball escape leaver is done. And is it possible to get an accurate hole placement for the base board?

1 answer

Answer 5 months ago

This is the way I did it hope this helps, used a 158 grain cast lead bullet for the weight, put it on one side only to keep it from hitting the trough.


Question 5 months ago on Introduction

Since I do not have a 3d printer I tried several online 3d printing companies. They all said problems with the files and do not recommend printing. (various reasons) Any body out there that has printed these files? If so what printer was used and what type of material. I would be interested in paying for the parts to be printed. Thanks

2 answers

Answer 5 months ago

I can see why that the printing companies are having problems. I am trying to print the parts and am having problems. My printers only have 22cm print beds so I cannot print the 5 sets at once. I have been trying to print the parts individually but have had problems finding all of the of them. The problem is that some of the parts are composite assemblies. 2B, 2C1 and 2C2 are actually two separate parts. 3D are also 2 part assemblies but the risers are of different heights. There looks to be at least 3 sizes of these parts. the parts 5C is also made up from two parts and 5B is made up from 3 parts.

so far I have printed all but 1e, 1f, 2a, 3d, 3f, 4a and 4f. The printing issues with 1d and 1e is the 'ring' where the ball drops through is rounded at the bottom so it does not bond to to the printing plate even with a skirt and supports.

When I can print a complete set that works I can print them and sell you one by posting on e-bay at cost + shipping if that is allowed on instructables and id ok with gocivici.


Reply 5 months ago

Hallo, sorry das ich in deutsch schreibe.
Ich habe alles nach und nach einzeln gedruckt hat wunderbar geklappt warte jetzt noch auf die kugeln.


Question 5 months ago

Thank you very much for paying so much for this project. I hope to implement it before the Spring Festival, and then learn SW to add my own ideas. When I looked at the stl file, I found that there were four missing parts, two of which had only one part, while the other two were completely absent. as the picture shows.
Do you have a more complete stl file? Thank you very much if you have time to update!