Introduction: Copernican Orrery: Replacing Hand Crank With Gear Motor
This instructable shows how I took plans purchased online for an Orrery and modified the design to replace the hand crank with a gear motor. The enclosure for the Orrery was customized, and I'll review at a high level how I came up with the design. This tutorial shows specifically how I used Adobe Illustrator to modify the design to add a gear motor to power the Orrery. It is not a tutorial on how to make an Orrery.
The original design for the orrery was purchased from Clayton Boyer designs. This tutorial does not contain any files from those plans. The gear ratios and parts list were really the only thing on this build that wasn't modified. The goal was to get a powered Orrery that didn't need to be cranked by hand.
Step 1: Designing and Creating the New Enclosure
The original plans used a hand crank to move the gears. I wanted something that could run off a gear motor to rotate the planets. The original enclosure was open and had an asymmetrical shape to accommodate the hand crank. I also wanted to make my Orrery have a Zodiac theme, so I made the modified enclosure a dodecagon, or 12 sided. That allowed me to add the zodiac names and constellations to each piece of a 12 sided pie. By alternating colors on the top faces, it allowed me to hide the fact that the support layer underneath was 2 separate pieces.
The first image shows the outline of the original enclosure shape, and how I sized the dodecagon to be big enough to have the gears fit inside, and allow 1/8" side walls. I used the same gear that was used for Mercury planetary wheel to mount on the gear motor. I offset the placement of that so that it would also fit inside the enclosure.
I used Illustrator to trim the pieces to sizes that could be cut on a Glowforge, as the maximum height without using the passthrough slot is 11".
Step 2: Designing the Motor Mount Platform
I used a 3 RPM Gear motor from ServoCity, and also a 6mm D-Bore hub to attach to the laser cut gear. Servocity also posts the measurement schematics for all their parts, as well as a STEP file for download, which makes it easy transfer dimensions to your vector design software. This made it easy to design a mount for the gear motor that could be laser cut on my Glowforge. In addition to the images displayed above, I have included the SVG file for the motor mount platform and gear.
Basically, the platform had to be tall enough to ensure that the gear was 1/8" off the floor and line up with the bottom drive wheel. It also had to be open on one side so the gear wouldn't be obstructed. There are 4 stanchions that pressure fit into 2 layers of 1/8" plywood that have the appropriate holes to fit the gear motor.
Step 3: Gear Motor -> Drive Wheels -> Planetary Wheels
The gear motor is reversible, and turns the drive wheels which turns the planetary gears. The gear motor can plugged into a 12V battery or directly into the wall and run continuously.
Step 4: Build Completion
Just to showcase the completion of the Orrery. The planets are marbles purchased on Amazon and Etsy. The artwork for the Zodiac images and constellations were purchased off Creative Market. The faces of the enclosure are made out of proofgrade Walnut, maple and clear acrylic. I chose clear acrylic so you could still see the gears moving on the inside. I love how the Orrery turned out!
Participated in the
Make it Move Contest 2020