Your CoreXY doesn't have to compromise on accuracy, nor speed!

Mount linear encoders on the physical X/Y axes, mix signals in pure hardware, and feed perfect motor-domain A/B feedback to your controller.
No firmware hacks, no CPU overhead, no more VFAs!

What It Does

This compact hardware module mixes two independent ABZ quadrature encoder signals (e.g., linear X and Y) in real time:

• OUT1 = X + Y → pure Motor A equivalent
• OUT2 = X - Y → pure Motor B equivalent
• Z_out = Z_x XOR Z_y → for your convenience

Plug your axis encoders in → get the clean, low-latency ABZ signals your motion controller expects.

Key Benefits

• Enables true closed-loop with linear encoders on Duet 1HCL and similar boards
• Zero software latency, propagation delay as low as 73 ns @ 5.0 V
• Up to 12.0 Mbps error-free output bandwidth (frees up to 35+ MIPS in your high-speed control loops)
• Plug-and-play: no firmware mods, standard TTL quadrature compatible
• Built-in ACTIVITY LEDs give instant visual feedback (1 blink = 1 step)
• Wide voltage range: 3.3 ±0.3 V ~ 5.0 V ±0.5 V (<100 mA)

The Core Problem: Domain Mismatch in Differential Kinematics

Most motion controllers (Duet3 1HCL, ODrive, many industrial servos) expect encoder feedback to match each motor's rotation. In CoreXY and differential-drive systems, this creates issues:

• Motor-mounted rotary encoders give precise motor angles but can't correct downstream errors (belt stretch/slip, pulley eccentricity, backlash, torsion, stiction, bearing play). This leads to artifacts like ringing, Vertical Fine Artifacts (VFAs), and dimensional inaccuracies, even in closed-loop mode.
• Linear encoders on the X/Y axes deliver true effector position (ideal for accuracy), but popular controllers usually have only one ABZ encoder input per motor, or require software to fuse X and Y into A/B (adding latency, CPU load, and needing dual ABZ inputs in hardware).

Result: You sacrifice true positional accuracy or fight hardware/firmware limitations and performance penalties.

The fix is hardware-level mixing, transforming linear X/Y feedback into motor-domain A = X+Y and B = X-Y signals, so your existing controller sees exactly what it wants, with zero software involved.

Killer Features

　1) Ultra-Simple Setup

Standard kit includes all crimp connectors.
Works out of the box with most quadrature encoders.

　2) No CPU Overhead, Minimal Latency

Hardware-only processing eliminates software sensor fusion delays.
Lab tested up to full spec ー see scope traces below.

　3) "Fake" Cartesian Mode (Controller Agnosticism)

Trick industrial servo drives and single-encoder-per-axis controllers into thinking they’re driving a standard Cartesian stage: perfect for retrofitting CoreXY mechanics!

Applications

• CoreXY 3D printers with linear encoders (Voron, RatRig, etc.)
• Differential drive robot wrists / joints (geared, timing belts, capstan, etc.)
• Any coupled kinematic system needing sum / difference feedback

Specifications

*Error rate < 0.001 ppm

Important Warnings & Recommendations

• Sold as-is for integration (sub-component), no warranty
• Buyer of the kit version (headers unsoldered), ground pads do not have thermal relief
• Do not exceed ratings
• Inputs are unprotected / unterminated
• All I/O share common GND / VDD net (beware unintentional ground loops & parallel PSUs)
• Controller must support the Min Output Edge Separation time even if the mixer is fed slower than Max Input Bitrate input streams

• For best performance:

  • Use 5.0V supply voltage
  • Ensure stable electrical supply
  • Keep the leads as short as possible, especially between the mixer and the controller

Performance assessment

Each sold unit is individually tested for error-free processing of at least 1 Gib of data simultaneously streamed to both ABZ inputs of the mixer at the combined inputs' Max. Error-free Bitate at 3.3V.

Extras

• Standalone mixer ICs (QFN package) + documentation available on request
• Custom speed variants or engineering support: contact via message

Shipping worldwide from Japan* via Tindie. For the relevant destinations, import tariff is not included in the listed price of the goods

Special Launch Price: $42 for the first 12 units
(because sometimes the answer really is 42 😉 – after that, regular price $55).

Questions about:
- Signals over differential pairs?
- Higher/Lower speed variants?
- I/O signals galvanic isolation?
- Other?

➡️ Message me!
Happy to help with concerns regarding wiring, integration, or shipping.

THANK YOU! For supporting a small hardware maker! 🚀