Easy Rotary Stage V2 - Gridfinity Compatible - CAD Provided

Intro

The Easy Rotary Stage is a an open sourced fully printable rotary stage. The design leverages a fully printed cycloid gear and worm screw combo making is really cheap and easy to produce.  This design is fully open sourced and more updated versions may be available on the GitHub repository for the project:

https://github.com/SGTHANKI/EasyPrintedStages

Detailed build instructions can be found on my personal website alongside different build configurations.

https://www.tomsvault.org/My+Projects/Easy+Stages/Rotary/Printed+Easy+Rotary+Stage

The design features two bolts that can be used to “tighten” the design, compensating the manufacturing tolerances. Building is relatively simple but head to my website for detailed instructions.

The stage is part of a larger ecosystem of 3D Printed Parametric Laboratory hardware including a linear stage, syringe pump, and clamp/retort stand system. You can find those designs here on Printables under my account, via my website (linked above) or via my GitHub (also linked above).

This design alongside an ESI sprayer were presented at the BMSS AI SIG conference in Nottingham 2025, where a talk was also given on the chemical compatibility of printed polymers. More information on that can be found on my personal website (linked above) though specifics cannot be shared before a scientific paper on the subject matter is published due to publisher copyright restrictions, though all work will be open once we are able.

All CAD designs are done in FreeCAD and are shared alongside the 3mf design files. If you remix or make new hardware for this please let me know, I would be happy to allow contributions to the repository. We have a discord server for the open lab hardware project this is a part of:

https://discord.gg/n7evB8ZUgx

Build Options:

The design is built to be as modular as possible and users are encouraged to download FreeCAD and export the model to 3mf files for printer directly from the CAD files instead of using those provided. Numerous mounting solutions are also provided for the stage.

Optional Gridfinity Standard Mounting Plate
The FreeCAD design makes use of the Gridfinity Workbench within FreeCAD. A 2x2 unit Gridfinity base plate is provided in the design that can be screwed into the base of the stage. Additionally a 4x4 unit bolt together mesh is provided to act as a starting point for mounting a Gridfinity based stage system. 

Mounting bolts for the Gridfinity base plate go through the magnet holes on the plate base. The above image is for the Easy Linear Stage (find it under my profile) but the designs are inter-operable.

Note: If you make a custom base larger than 2x2u, you will need to quickly pocket the holes all the way through the plate. This has already been done on the provided 2x2u base.

Optional Top Plate

An optional top plate can be printed with the design. It mounts via 4 M3 bolts in the corners of the plate. You can also make custom mounting plates with the original FreeCAD designs, just delete the last 2 operations on the body and you'll have a nice blank plate. Again, its the same top plate as used in the other easy stages I've published.

The mounting plate features a grid of 2.6mm diameter holes, these are the perfect size for M3 bolts to thread into without the need for threaded inserts. The holes are spaced 5mm apart to make designing custom mounting hardware as easy as possible. 

Clamp, Bolt Down Mounts and Other Stages

On my Printables profile and linked below you'll find a clamp for the top mounting plate and a simple bracket to make bolting this thing down a lot easier. You can also mount other stages from the Easy Stage ecosystem I've made to the top of this one or mount this one to the top of one of those with basic M3 bolts. 

• https://www.printables.com/model/1196342-easy-stage-side-mounted-bolt-down-bracket-cad-prov
• https://www.printables.com/model/1194436-easy-stage-clamp-accessory-cad-provided
• https://www.printables.com/model/1180242-easy-linear-stage-v2-gridfinity-compatible-cad-pro

Assembly Instructions

Step 1: Print it

Print the cycloid gear and worm gear using a high quality settings at 100% infill ideally in pure PETG, no carbon or glass fibre reinforcement. Print the cycloid with no supports and print the worm gear with automatic tree supports with the hand dial on the print bed as you see below: 

All the other parts can be printed however you want really. I used PETG-CF for them in the pictures. 

Step 2: Mount the Cycloid and Lube the Top Plate

Mount the cycloid gear as seen below. The triangle embedded onto the base of the triangle and on the base of the stage will aid in alignment.

DO NOT FULLY TIGHTEN THE BOLTS YET

Leave about 3mm space between the gear and the base plate. You tighten these later once the rest of the stage is installed.

Step 3: Insert the Worm Gear and Spacer into the Mid-plate B

READ THIS ITS REALLY IMPORTANT!!!

This part is important. Lube the worm gear and slide it into the Mid-plate B. There will be quite a lot of play and this is by design. The small “puck” shaped part called the worm gear spacer slides down the end of the worm gear, the side with the hole in it faces away from the gear. There's a hole in the side of the mid-plate for an M3 bolts that you can tighten down onto that spacer, tighten it until the worm gear can still spin but has no play. 

Step 4: Bolt the Mid-Plates Together and Tighten Down the Cycloid Gear

There are two M3 counter bored holes on the worm gear side of the casing. Into these two M3 bolts can be placed that will mate with the other side of the case. Tighten these until the two halved are together and can move freely with no play. You'll need a long hex bit to reach the two M3 bolts once they're in the counter bored holes in the mid-plates. You may need to adjust this over time as the gears wear into each other. Avoid over tightening. You can also tighten down the bolts on the cycloid now and make sure there is no play but that it can still spin freely. Make sure to lube everything as you go. You'll need a long hex bit to reach the two M3 bolts once they're in the counter bored holes in the mid-plates. 

Step 5: Mount the Base Plate

The plate with two channels on it fits into the grooves on the front and base parts of the case, there are two bolt holes that lock this into the case and then prevent any movement. These are M3 bolts and have counter bored holes. The other holes in this piece are for either the gridfinity base plate or to bolt it down to another stage from the easy stage ecosystem.