ShiftLab – Modular Shift Knob System | Classic, Kunai & Katana

ShiftLab – Modular Shift Knob System

Mix. Match. Build Your Own.

Why settle for one shift knob when you can build your own?

ShiftLab is a fully modular and customizable shift knob system designed for 3D printing and compatible Thrustmaster shifters.

Instead of creating individual shift knobs with fixed designs, I wanted to build a system where components could be mixed, matched, rearranged and reused to create entirely different styles.

The result is ShiftLab — a collection of interchangeable bases, grip modules, shape adapters, end caps and decorative accessories that work together to create your own personalized shifter.

Start with a classic cylindrical grip, turn it into a kunai-inspired design, build a katana-inspired handle, or combine elements from all three to create something entirely new!

Three Styles, One System

ShiftLab currently includes three main configurations:

• Classic Shifter – A traditional cylindrical shift knob with interchangeable grip rings.

• Kunai Shifter – Inspired by the iconic Japanese kunai, featuring a circular grip, a distinctive ring end cap and a decorative blunt blade.

• Katana Shifter – Inspired by Japanese sword handles, featuring oval grip modules, a kashira-inspired end cap, a decorative blunt blade and a habaki-inspired collar.

These aren't three separate systems. They all share the same modular platform, allowing you to exchange components between different configurations.

Modular by Design

1. Interchangeable Bases

Choose from 7 different base lengths, ranging from 6 cm to 12 cm in 1 cm increments.

All bases feature female threads on both ends, designed around the Thrustmaster-compatible thread system.

Choose your preferred length, or connect multiple bases together for even more possibilities.

2. Stackable Grip Modules

Build your grip using interchangeable modules available in two main profiles:

• Round Grip Modules – For cylindrical grips, Classic Shifters and Kunai-inspired designs.

• Oval Grip Modules – For ergonomic, katana-inspired handles.

Mix different module shapes and arrangements to create unique grip profiles, textures and silhouettes.

3. Round-to-Oval Shape Adapter

Can't decide between round and oval?

You don't have to!

The included Shape Adapter creates a transition between circular and oval grip modules.

The same component works in either direction, allowing you to combine both profiles within a single grip.

4. Interchangeable Threaded End Caps

Complete your creation with one of three end cap styles:

• Flat End Cap – A clean, classic cylindrical finish.

• Ring End Cap – Inspired by the traditional kunai ring pommel.

• Kashira End Cap – Inspired by the end fitting of a Japanese katana handle.

Each end cap is designed to complete its respective configuration while remaining part of the interchangeable system.

5. Decorative Blade Modules

The Kunai and Katana configurations also include optional, stylized blade components to complete their distinctive designs.

Both blades are intentionally blunt, with rounded edges and truncated tips, removing the traditional sharp points and cutting edges.

These pieces are decorative design elements, not functional blades or weapons.

Included components:

• Kunai Blunt Blade – A stylized kunai-inspired blade with a rounded, truncated tip.

• Katana Blunt Blade – A decorative katana-inspired blade with softened edges and a truncated tip.

• Katana Habaki Collar – A separate collar inspired by the traditional Japanese fitting found at the base of a katana blade.

The Habaki Collar includes two clearance variations:

• 0.3 mm clearance – For a closer fit.

• 0.4 mm clearance – For additional tolerance if your printer produces tighter-fitting parts.

These options allow you to choose the version that works best with your printer's dimensional accuracy.

6. Threaded Coupler

The included Threaded Coupler adds another level of customization.

Use it to:

• Connect two ShiftLab bases together.

• Extend the overall height of your shifter.

• Connect compatible shift knobs designed by other members of the 3D printing community.

Beyond ShiftLab – Community Compatibility

ShiftLab isn't limited to its own designs!

The interchangeable bases can also function as shifter extensions for compatible community-created shift knobs.

With the included threaded coupler, you can combine ShiftLab components with other designs that use the same compatible thread standard.

This means you can use ShiftLab not only to build a new shifter, but also to customize and extend an existing one.

Note: Compatibility with third-party models depends on their thread dimensions and design.

How to Assemble

1. Choose your base – Select the length that works best for your setup.

2. Build your grip – Stack your preferred round or oval grip modules.

3. Mix shapes – Use the Shape Adapter whenever transitioning between circular and oval modules.

4. Choose an end cap – Finish your design with a Classic, Kunai or Katana-inspired end cap.

5. Add decorative details – For Kunai or Katana configurations, include the corresponding blunt blade components and, for the Katana, select your preferred Habaki Collar fit.

6. Extend if needed – Use the Threaded Coupler to connect additional bases or compatible community designs.

7. Install your shifter – Secure the completed assembly to your compatible shifter.

3D Printing & Assembly Tips

• Print the components in your preferred colors to create custom combinations.

• Check the fit of threaded connections before final assembly.

• If threads are too tight, check your printer's dimensional accuracy and tolerances rather than forcing the parts together.

• For the Katana Habaki Collar, choose between 0.3 mm and 0.4 mm clearance according to your printer's tolerances.

• Make sure all modules and threaded connections are securely assembled before use.

• Decorative blade components are intended for aesthetic purposes only. Ensure they are securely fitted and do not obstruct normal shifter operation.

Make It Your Own!

ShiftLab was designed around one simple idea:

Your shifter shouldn't be limited to a single design.

Experiment with different lengths, shapes, textures, colors and combinations.

Whether you prefer a minimal racing setup, something inspired by Japanese weapons, or an entirely original creation, ShiftLab gives you the freedom to build it.

And because the system is modular, new components and designs can expand the possibilities even further.

One system. Countless configurations.

Happy printing! 🏁

Credits & Licensing

Designed for compatibility with the Thrustmaster TH8S Shifter.

Official TH8S reference files provided by Thrustmaster:

https://www.printables.com/model/1825116-thrustmaster-official-th8s-gear-knob-files

Official reference files licensed under CC BY-NC-SA 4.0.

ShiftLab is an independent community project and is not an official Thrustmaster product.