Air Cooled Spindle

An air-cooled spindle is a fan-cooled, maintenance-free electric motor for CNC machines, operating at 18,000-24,000 rpm. Widely used in CNC routers, engraving, wood carving, plastic cutting, and light metal milling, it requires no pump or coolant, making it ideal for dry cutting and dusty environments. Unlike water-cooled spindles, this type of air-cooled spindle offers lower maintenance and easier installation, with typical noise levels of 65-80 dBA.

Air Cooled Spindle Types and Their Key Features

ATO offers 9 models of air-cooled spindles, ranging from low-power hobby machines to high-power industrial spindles. Choose the right spindle based on power, torque, speed, collet size, and voltage.

Low Power Air Cooled Spindle（ATO-SPINDLE-A800 / ATO-SPINDLE-A1500）

• Power: 800W (0.31 Nm) and 1.5kW (0.58 Nm), both at 24,000 rpm.
• Collet: ER11, supporting tool shanks up to 7mm.
• Voltage: 3-phase 220V AC at 400Hz.
• Low cost, ideal for wood carving, CNC machines, and basic engraving.
• Air-cooled with an integrated fan, maintenance-free, and easy to install.
• Lightweight design suitable for hobby CNC routers and small automation systems.

Mid Power Air Cooled Spindle（ATO-SPINDLE-1A1500 / ATO-SPINDLE-A2200 / ATO-SPINDLE-1A2200）

• Multiple speed/torque configurations: 1.5kW at 18,000 rpm (0.91 Nm, 220V, 300Hz); 2.2kW at 24,000 rpm (0.85 Nm, 220V, 400Hz); and 2.2kW at 18,000 rpm (1.1 Nm, 380V, 300Hz).
• All models use an ER20 collet (max tool shank 13mm).
• 18,000 rpm versions deliver higher torque for hardwood, aluminum, and light steel.
• 380V version (1.1 Nm) operates at lower current, reducing heat and improving efficiency.
• Suitable for CNC routers, engraving machines, and continuous production tasks.
• Stable performance, low noise, and long service life.

High Power Air Cooled Spindle（ATO-SPINDLE-A3500 / ATO-SPINDLE-A4500 / ATO-SPINDLE-A6000 / ATO-SPINDLE-A7500）

• Power range: 3.5kW to 7.5kW, all running at 18,000 rpm.
• Voltage: 3-phase 380V AC at 300Hz.
• Torque from 1.68 Nm (3.5kW) up to 3.58 Nm (7.5kW).
• Collet sizes: ER25 for 3.5kW, ER32 for 4.5kW-7.5kW (max shank 20mm).
• Models ≥4.5kW feature 4 pieces of P4 grade ceramic ball bearings.
• IP50 protection grade (7.5kW) with a powerful built-in fan.
• Common in industrial CNC routers, metal drilling and milling equipment, and heavy-duty engraving.
• Low noise, high accuracy, designed for 24/7 production.

Air Cooled Spindle Selection Guide

Air-cooled spindles are critical for CNC routers, engraving machines, and milling equipment. Choosing the right model depends on power, speed, torque, collet size, and voltage. The table below offers a quick comparison of all ATO models.

Key Considerations When Choosing an Air Cooled Spindle

• Cooling efficiency: Air-cooled spindles rely on an integrated fan, perfect for intermittent use and dry materials; for 24/7 operation, monitor temperature.
• Torque vs. Speed: Low-power spindles lose torque at low rpm; choose 18,000 rpm models (e.g., 2.2kW/380V) for metal cutting.
• VFD requirement: All air-cooled spindles must be driven by a VFD matching voltage, phase, and frequency (300Hz or 400Hz); never connect directly to mains.
• Bearings: Models ≥4.5kW use P4 grade ceramic ball bearings, reducing runout and extending life at high speed.
• Dust protection: Most air-cooled spindles are IP50 rated; for extremely dusty environments, add dust collection or clean bearings regularly.
• Mounting size: Check your CNC router’s clamp diameter; our spindles typically have a standard 80mm or 100mm mounting body.
• Noise level: Air-cooled spindles produce 65-80 dBA; 18,000 rpm models are quieter than 24,000 rpm ones.

FAQs of Air Cooled Spindle

Q1: What is the difference between an air-cooled spindle and a water-cooled spindle?
A: An air-cooled spindle uses an integrated fan, is maintenance-free, and lighter, ideal for wood and plastic. A water-cooled spindle requires a pump and coolant, runs quieter, and suits longer continuous duty.

Q2: Can I run an air-cooled spindle without a VFD?
A: No. All air-cooled spindles are 3-phase AC motors that require a VFD to control speed and provide correct voltage/frequency (220V or 380V at 300Hz/400Hz).

Q3: Which collet size do I need?
A: ER11 (max 7mm) for 800W-1.5kW; ER20 (max 13mm) for 1.5-2.2kW; ER25 (max 16mm) for 3.5kW; ER32 (max 20mm) for 4.5-7.5kW. Match the collet to your tool shank.

Q4: What is the advantage of a 380V air-cooled spindle over a 220V?
A: 380V spindles operate at lower current for the same power, reducing heat and delivering higher torque (e.g., 2.2kW 380V gives 1.1 Nm vs 0.85 Nm at 220V).

Q5: Can I use an air-cooled spindle for aluminium milling?
A: Yes. Choose a higher torque model like 2.2kW (18,000 rpm, 380V) or 3.5kW/4.5kW, use shallow cuts, proper feed rate, and mist lubrication.