Dragonfly - Extension: Arms

➕ Dragonfly – Extension: Arms

Already own the main Cave Slime Dragonfly set and want to track both arms? This extension pack adds two full-fledged trackers for your left and right arms – with no need for an additional USB dongle. Pair them with your existing set to capture fluid elbow movement, forearms, and natural arm gestures.

• ✅ No Extra Dongle: Connects directly to your existing Dragonfly USB receiver – no extra network setup.
• ✅ Arm Straps: Comfortable and secure fit around biceps or forearms (custom lengths available upon request).
• ✅ Instant Expansion: Plug & Play addition for full upper-body tracking in extended tracking setups.

📦 Package Contents

This compact pack includes everything required for immediate setup on both arms:

• ✅ Included: 2× main Cave Slime Dragonfly unit.
• ✅ Included: 2× comfortable elastic arm mounting strap.
• ✅ Included: 2× plastic tracker holder.
• 🏷️ Stickers: For clear and easy identification of left and right trackers.

🎯 ICM-45686 Sensor: Surgical Precision

Just like the entire Dragonfly series, this extension relies on the top-tier ICM-45686 sensor from TDK InvenSense. It delivers minimal drift, ultra-low noise, and rock-solid stability during fast arm movements, dancing, and expressive gestures.

• 🎯 Surgical Precision: Smooth and reliable tracking of elbow positions and arm rotations.
• 🛠️ 6-Axis Factory Calibration: I carefully test and calibrate each unit on 6 axes before shipping.
• 🔋 Energy Efficient: Low sensor power consumption combined with radio transmission saves battery life.

🧲 Optional Magnetometer Wiring

As part of custom manufacturing, I offer the option to have the magnetometer circuit physically connected or disconnected. Before choosing the upgrade, please consider the essential differences:

• 🟢 Disconnected (standard mode, recommended): Maximum battery life per charge (~50 hours). The trackers perform reliably with standard motion sensors and are entirely immune to magnetic interference in your room. I recommend this option for the vast majority of users.
• ⚙️ Connected (requires tuning, half battery life): Hardware-activated magnetometer support offers yaw drift compensation, but comes with strict limitations:

• 🧭 Effective only in magnetically clean environments: The magnetometer assists with rotation drift using Earth's magnetic field. However, it is beneficial only in a completely magnetically clean environment. In an everyday play area with magnetic interference (speakers, subwoofers, nearby power banks, wireless chargers, bundled power cords, or motorized desks), tracking can actually become unstable and perform worse than without it.
• 🔋 Permanently reduced battery life: Physical circuit wiring reduces battery life by approximately 50% (~30 hours of operation), even if you subsequently disable the magnetometer in the software or console.
• 🛠️ Requires precise calibration: Proper operation requires thorough calibration in an interference-free space and manual fine-tuning in software.

⚠️ Connecting the magnetometer is strictly recommended for experienced users and enthusiasts who have an interference-free room, enjoy fine-tuning their setup, and accept the reduced battery life.

🎮 Compatibility & Use Cases

The arm extension integrates seamlessly into your existing SlimeVR setup and is supported across all major VR applications and headsets without external sensors:

• 🌐 Apps & Games: VRChat, Resonite, ChilloutVR, Dance Dash, NeosVR, Virtual Motion Capture (VMC), and VTubing software.
• 🥽 Supported Headsets: Meta Quest 2 / 3 / Pro, Pico 4, Valve Index, HTC Vive, and other PCVR and standalone headsets (via SteamVR, Virtual Desktop, or Link).
• 💃 Why Add Arm Trackers: Eliminates inverse kinematics (IK) guesswork for elbows, delivering authentic arm poses and lifelike gestures.

⚙️ Setup, Comfort & Maker Support

I ensure that wearing and using the arm trackers is comfortable without restricting natural upper-body movement:

• 🖥️ SlimeVR Server: Pairing with your existing USB dongle takes only a few seconds in the SlimeVR Server application.
• 🧵 Ergonomics & Straps: Elastic straps securely hold the tracker on your arm without pinching. The tracker itself weighs only 17 g, making it barely noticeable during gestures.
• 🛠️ Durable Build & Support: Tough PETG enclosures stand up to active movement. As a maker, I offer direct customer support, repair services, and replacement parts.

❓ Frequently Asked Questions (FAQ)

📊 Technical Specifications

I manufacture the tracker enclosures myself using 3D printing with high-grade PETG material. Custom color options are available upon request.