Portable Mirror Ball Motor for Small Events and Band Stage Use

A friend of mine asked if I could build a motor for his small mirror ball. He wanted something compact and easy to move around - something that could bring a bit of sparkle to house parties and small live shows.

This project is my take on that idea: a lightweight, portable mirror ball motor that’s simple, quiet, and reliable enough for regular use on stage. It features two selectable rotation speeds, so you can adjust the mood from a slow, subtle spin to a more energetic disco vibe.

It’s designed to run smoothly for long periods, be quick to set up, and use easily available parts. If you’ve ever wanted to add a classic disco ball effect to your event setup without relying on bulky commercial units, this build might give you some ideas!

1. 3D printed parts (3MF files provided)
2. 1 × 40 mm M5 bolt
3. 1 × 30 mm M5 bolt
4. 2 × M5 nylon lock nuts
5. 1 × M5 nut
6. 2 × 35 mm M4 bolts
7. 2 × M4 nylon lock nuts
8. Washers (for M4/M5 bolts as needed)
9. 1 x M5 locking washer
10. 8 × self-drilling M3 screws, 10 mm
11. 4 × 1N4001 diodes
12. 3 cm x 3 cm piece of prototype board
13. 1 × power connector
14. 1 × On-Off-On switch
15. 1 × N20 gear motor (example link)

Print the following files. You’ll need one of each, except for Clamp.3mf, of which you’ll need two.

I used PETG for its durability and heat resistance, but PLA+ or ABS should work just as well for this project.

Print with a 0.2 mm layer height and supports enabled where needed.

In the slicer, I also used the fuzzy surface feature on the outer walls, which gives the printed parts a slightly textured and more pleasant look.

For reference, I printed the parts on an Anycubic Kossel using PrusaSlicer.

Tip: When printing the clamps (Clamp.3mf), orient them at a 45° angle in your slicer. This orientation makes the parts stronger compared to printing them upright. I’ve included a screenshot from my slicer settings to show the orientation I used.

Start with the 40 mm M5 bolt as the main shaft. Assemble the following parts onto the bolt in this order:

1. Lock washer – a slightly cut and bent washer that acts as a spring. Its purpose is to lift the bolt head slightly above the bearing surface.
2. Bearing – slides onto the bolt and will support the rotation.
3. M5 nut (lock nut recommended!) – tighten securely to hold the bearing in place. Using a regular nut may result in the assembly coming loose, so a lock nut is important.

Next, press the 3D printed gear onto the end of the bolt. The gear is designed to snap on tightly. Ensure that the small lip or ridge on the gear faces down toward the bearing.

Now attach the assembled shaft to the bottom_housing.3mf part. The bearing should fit snugly into its recess in the housing.

Once everything is in place, check that the gear can rotate freely on the bearing without wobbling.

We’ll now set up the power and speed control circuitry for the mirror ball motor.

1. Prepare the diodes:
2. You need four 1N4001 diodes.
3. Solder them in series, making sure to respect the polarity: the white stripe on each diode indicates the cathode. The current flows from the unmarked side to the striped side. Incorrect orientation will prevent the circuit from working.
4. This series of diodes will drop the voltage by roughly 2.8 V, effectively halving the 5V supply to the mirror ball and reducing the motor speed accordingly.
5. Mount the diodes on a small prototype board:
6. I used a 3 × 3 cm board.
7. Glue the board to the housing_bottom.3mf part using hot glue.
8. Connect the power source and switch:
9. Solder a wire from the + terminal of the 5V DC power supply to one side of the On-Off-On switch.
10. Solder another wire from the other side of the switch to the start of the diode chain (the end without the white stripe).
11. Connect the motor:
12. Finally, solder wires from the - terminal of the power supply and the center terminal of the switch to the motor leads.

Once everything is connected, test the setup by flipping the switch to verify that the motor spins at two selectable speeds. Make sure the motor rotates in the correct direction (main shaft clockwise) and that all connections are secure. If shaft rotates counterclockwise, switch wires on the motor side.

Tip: Double-check all solder joints and polarity before powering up to avoid damaging the diodes or the motor.

Start by pressing the 3D printed gear onto the motor shaft. The gear should fit snugly and sit flush on the shaft.

Next, position the motor in the bottom_housing.3mf part with the gear facing down toward the main shaft.

Secure the motor using the Motor_clamp.3mf part. Attach the clamp to the housing with two self-drilling screws. Make sure the motor is held firmly in place so that the gear meshes properly with the main shaft gear.

Finally solder wires to the motor.

Note: The motor used here has a built-in high-reduction gearbox, so it is normal that the shaft cannot be rotated by hand after installation.

Motors are available in different RPM ratings. The printed gears in this build have a 1:3 ratio, meaning the mirror ball rotates three times slower than the motor shaft. Typically, mirror balls rotate slowly, around 2–10 rpm. A motor geared for about 25 rpm on the shaft is a good choice. I used a 60 rpm motor, so in this version the mirror ball spins a bit faster than ideal. I’m considering ordering a slower motor and swapping it in for a more suitable speed.

Start by attaching the 30 mm M5 bolt to the housing_top.3mf part. The bolt should fit tightly into the slot designed for it.

Next, place the top housing onto the bottom housing and secure it with six self-drilling screws. Make sure the edges align neatly and the housing sits flat.

Now install the clamps (Clamp.3mf):

1. On the top side, add a couple of washers between the housing and the clamp, then secure it with an M5 nylon lock nut.
2. On the bottom side, thread a regular M5 nut onto the bolt first, then add the clamp and tighten it in place with another M5 lock nut.

Each clamp also holds an M4 bolt that serves as a mounting rod for the motor and the mirror ball. These should be fastened using M4 nylon lock nuts to ensure they don’t loosen during use.

Lock nuts are especially important in this step — if any of these nuts come loose, the mirror ball could fall. Tighten the upper clamp just enough to prevent it from rotating, and snug the lower clamp securely between the two nuts.

Finally, double-check all connections and mechanical parts before hanging the unit.

⚠️ Safety Note:

If the mirror ball is installed above people, always use a secondary safety cable or chain in addition to this motor mount. This ensures the ball cannot fall even if a mechanical failure occurs.