Monome Arc Clone - Ultra-Thin 12.5mm Edition
Monome Arc Clone - Ultra-Thin 12.5mm Edition
What is it?
The Monome Arc Clone — Ultra-Thin 12.5mm Edition is a meticulously engineered replica of monome’s arc controller, available in Arc2 (two-knob) and Arc4 (four-knob) configurations. Each knob features a high-precision encoder with 64 discrete steps per revolution, perfectly aligned with a 64-segment RGB LED ring for visual feedback. Knobs support push-button functionality, replicating the original flagship version’s behavior for Max/MSP applications.
Encased in a premium 3D-printed shell using Kexcelled art filament with metallic finish, the controller measures just 12.5mm thick (9mm middle frame) — a dramatic reduction from the original’s 38mm height. Connectivity via USB-C. Each unit carries an independent serial number. Fully compatible with the monome ecosystem: norns, serialosc (Windows/Mac), and Max/MSP. A forthcoming firmware update will enable iii system support for standalone USB-MIDI operation with Lua scripting.
Why did you make it?
This project began alongside our Grid clone development, with the goal of creating the most complete and aesthetically refined Arc replica available. Existing clones suffered from three critical limitations: excessive thickness, inconsistent norns compatibility, and hardware quirks from early open-source designs. Most DIY monome controllers work with Max/MSP but are “officially unsupported” for norns and require hacking the C codebase to function.
We undertook a complete redesign — rewriting the firmware from scratch and redesigning the PCB layout over six months. Challenges addressed include the unique Arc–norns handshake protocol, encoder acceleration data handling, stable high-refresh-rate performance, and non-functional USB expansion ports found in the original open-source files. The result matches the original’s tactile precision while surpassing it in portability and ecosystem integration.
What makes it special?
- Unprecedented thinness — 12.5mm total thickness, the slimmest Arc clone available; pairs seamlessly with our Grid clone for a unified monome setup
- Full norns compatibility out of the box — a significant breakthrough; most DIY clones struggle with norns integration, which assumes arc connectivity for parameter control and sequencing
- Future-proof iii support — hardware is ready for the 2025 monome iii system, enabling Lua scripting and USB-MIDI enumeration directly on the device — something even original pre-2025 arcs cannot do
- Premium build quality — metallic-finish Kexcelled filament; optional aluminum version; RGB LED rings support multi-color adjustment including yellow, white, and green to match norns screen aesthetics
- Hand-selected LEDs — each LED individually selected for consistent brightness and color accuracy, with a sophisticated diffusion stack: light shields, reflection layers, and frosted acrylic
- Custom ultra-thin encoders — designed in partnership with manufacturers; each unit hand-selected for precision
- Arc4: 256 RGB LEDs — equivalent to a full monome Grid 256; meticulous assembly with multiple 3D-printed diffusion layers and manual QC
- Laser-etched inner back panel — eliminates guesswork when locating I/O ports
- Ecosystem compatibility — works with serialosc (Windows/Mac), norns, VCV Rack Ansible module, and Max/MSP
- Long-term firmware support — regular updates based on community feedback; unique serial number per unit