1. Introduction
Thank you for choosing the HARDELL Mini Cordless Rotary Tool Kit. This manual provides essential information for the safe and effective operation, maintenance, and troubleshooting of your new tool. Please read this manual thoroughly before first use and retain it for future reference.
2. Product Overview
2.1 Key Features
- Compatibility: Compatible with 3/32-inch (2.3 mm) accessories.
- Precision Control: 6 variable speeds ranging from 18,000 to 38,000 RPM for diverse tasks.
- Upgraded Motor: Brushless coreless motor for lower noise, powerful performance, and reduced heat.
- Portability: Lightweight design (0.25 pounds) with a durable, rust-resistant aluminum casing.
- USB-C Rechargeable: 2000mAh battery, fully charges in 60 minutes via universal Type-C port.
2.2 Package Contents
The HARDELL Mini Cordless Rotary Tool Kit includes the following items:
- 1 x HARDELL 4V Mini Cordless Rotary Tool
- 1 x USB-C Charging Cable
- 1 x Spanner
- 1 x Allen Wrench
- 2 x Built-in Grinding Heads (set screws)
- 10 x Sanding Bands
- 10 x Sanding Paper discs
- 1 x Sanding Drum
- 1 x Wheel Mandrel
- 6 x Diamond Bits (Cutting)
- 1 x Diamond Bit (Cutting)
- 2 x Grinding Stones
- 2 x Wool Polishing Wheels
- 1 x Mandrel for Felt Wheel
- 1 x Nylon Brush
- Additional set screws for collet

Figure 1: HARDELL Mini Cordless Rotary Tool Kit with all components.

Figure 2: A comprehensive display of the 35 accessories included for various applications like sanding, cutting, grinding, and polishing.
3. Safety Instructions
Always follow basic safety precautions to reduce the risk of fire, electric shock, and personal injury when using this tool.
- Eye Protection: Always wear safety glasses or goggles to protect your eyes from flying debris.
- Secure Workpiece: Always secure your workpiece in a vise or with clamps to prevent movement during operation.
- Proper Ventilation: Work in a well-ventilated area, especially when grinding or sanding materials that produce dust.
- Inspect Accessories: Before each use, inspect accessories for damage. Do not use damaged accessories.
- Unplug/Power Off: Always turn off the tool and disconnect it from power (if charging) before changing accessories or performing maintenance.
- Avoid Overloading: Do not force the tool. Let the tool work at its own pace.
- Keep Clear: Keep hands, hair, and loose clothing away from rotating parts.
- Storage: Store the tool and accessories in a dry, secure place out of reach of children.
4. Setup
4.1 Charging the Tool
The HARDELL Mini Cordless Rotary Tool is equipped with a 2000mAh rechargeable battery. Before first use, fully charge the tool.
- Locate the USB-C charging port on the tool.
- Connect the provided USB-C cable to the tool and to a compatible USB power adapter (not included).
- The digital display will indicate charging status. A full charge takes approximately 60 minutes.
- Once fully charged, disconnect the cable.

Figure 3: Overview of the tool's features, including the Type-C charging port.
4.2 Attaching Accessories
The tool uses a collet system secured by set screws. Ensure the tool is powered off before changing accessories.
- Identify the two small set screws on the collet at the tip of the tool.
- Using the provided Allen wrench, carefully loosen both set screws. Do not remove them completely to avoid losing them.
- Insert the desired 3/32-inch (2.3mm) accessory shank into the collet until it is seated firmly.
- Tighten both set screws securely with the Allen wrench. Ensure the accessory is held firmly and does not wobble.

Figure 4: Step-by-step guide for securely attaching accessories using the collet and set screws.
Note: The kit includes additional set screws. Store them in a secure place to prevent loss, as they are very small.
5. Operating Instructions
5.1 Power On/Off
- To power on, press and hold the power button until the digital display illuminates.
- To power off, press and hold the power button again until the display turns off.
5.2 Speed Control
The tool features 6 variable speed settings, indicated on the digital display.
- Press the power button briefly to cycle through the speed settings (1 to 6).
- Speed 1: 18,000 RPM
- Speed 2: 22,000 RPM
- Speed 3: 26,000 RPM
- Speed 4: 30,000 RPM
- Speed 5: 34,000 RPM
- Speed 6: 38,000 RPM

Figure 5: Digital display illustrating the 6 available speed settings.
Recommendation: Start with a lower speed setting and gradually increase it as needed for your specific task and material. Higher speeds are generally for finer work or harder materials, while lower speeds are for polishing or delicate tasks.
5.3 Usage Tips
- Light Pressure: Apply light, consistent pressure. Excessive force can cause the tool to stall, overheat, or damage the workpiece.
- Material Compatibility: This tool is suitable for various materials including wood, plastic, soft metals, and ceramics. Always test on a scrap piece first.
- Applications: Ideal for polishing, sanding, engraving, drilling, and finishing 3D printed models.

Figure 6: Example of using the rotary tool for engraving on glass.

Figure 7: Various applications of the rotary tool including sanding, carving, grinding, and polishing.
6. Maintenance
- Cleaning: After each use, wipe down the tool with a clean, dry cloth. Use a soft brush to remove dust and debris from the collet area.
- Accessory Storage: Store accessories in their designated container to prevent damage and loss.
- Battery Care: For optimal battery life, avoid fully discharging the battery frequently. Charge the tool regularly, even if not in use for extended periods.
- General Inspection: Periodically check the tool for any signs of wear or damage. Do not attempt to repair the tool yourself; contact customer support if issues arise.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Tool does not turn on. | Low battery or no charge. | Charge the tool fully using the provided USB-C cable. |
| Accessory wobbles or falls out. | Set screws are loose or accessory is not properly seated. | Ensure the accessory is fully inserted and both set screws are tightened securely. |
| Tool stalls or loses power during use. | Excessive pressure applied or low battery. | Reduce pressure on the workpiece. Check battery level and recharge if necessary. |
| Tool does not start at lower speed settings (1 or 2). | Motor requires higher initial torque to start rotation. | Start the tool at speed setting 3 or higher, then adjust down if desired. |
| Tool overheats. | Prolonged heavy use or blocked ventilation. | Allow the tool to cool down. Ensure ventilation slots are clear. Reduce usage time for heavy tasks. |
8. Specifications
| Feature | Detail |
|---|---|
| Brand | HARDELL |
| Model Number | DM62501REDHD-1 |
| Voltage | 4 Volts |
| Power Source | Battery Powered (Cordless) |
| Battery Type | 2000mAh Lithium Ion (included) |
| Charging Time | Approx. 60 minutes (via USB-C) |
| Minimum Rotational Speed | 18,000 RPM |
| Maximum Rotational Speed | 38,000 RPM |
| Number of Speeds | 6 Variable Speeds |
| Collet Size Compatibility | 3/32-inch (2.3 mm) |
| Item Weight | 0.25 pounds (approx. 113 grams) |
| Product Dimensions (L x W x H) | 9.5 x 3.8 x 1.2 inches (approx. 24.1 x 9.7 x 3.0 cm) |
9. Warranty and Support
For warranty information or customer support, please refer to the product packaging or contact HARDELL directly through their official channels. You can visit the HARDELL Store for more information: HARDELL Store.