STF Round Air Cooled Spindle Motor 0.8-2.2 KW ER11 ER20
Overview
STF series round air cooled spindles are the workhorse of small and mid-size CNC routers. A coaxial fan pushes air along the motor body, so there is no water pump, radiator or hose to route - the spindle runs on power and nothing else. The range covers 0.8 kW in a 65 mm body and 1.5–2.2 kW in 80 mm bodies, with ER11 and ER20 collets at 24 000 rpm and 400 Hz.
Model range
| Model | Power | Voltage | Rated current | Collet | Body |
|---|---|---|---|---|---|
| STF65-0.8-ER11-220V | 0.8 kW | 220 V | 3.0 A | ER11 | Ø65 mm |
| STF80-1.5-ER11-110V | 1.5 kW | 110 V | 9.0 A | ER11 | Ø80 mm |
| STF80-1.5-ER11-220V | 1.5 kW | 220 V | 6.0 A | ER11 | Ø80 mm |
| STF80-2.2-ER20-110V | 2.2 kW | 110 V | see drawing | ER20 | Ø80 mm |
| STF80-2.2-ER20-220V | 2.2 kW | 220 V | 7.6 A | ER20 | Ø80 mm |
Common specifications
| Item | Value |
|---|---|
| Rated speed | 24 000 rpm |
| Rated frequency | 400 Hz |
| Cooling | Coaxial air cooling, fan integrated in the rear cap |
| Bearings | 0.8 kW: 7002DT pair + 6002; 2.2 kW: 7005DT pair + 6002 × 2 |
| Rated torque | 0.32 N·m at 0.8 kW; 0.88 N·m at 2.2 kW |
| Insulation class | Class F, S1 duty, ambient 40 °C |
| Collet nut | M14 × 0.75 (ER11), M25 × 1.5 (ER20) |
Air cooled or water cooled
The trade-off is simple. An air cooled spindle needs no pump, no hoses and no coolant, which suits job shops and machines that move between sites. It is also the cheaper of the two. The cost is noise from the rear fan, and a body that runs hot to the touch after a long cut. If your machine runs two or three shifts in the same cell, the water cooled STZ series holds temperature better and is quieter; if the machine is used intermittently, STF is the lower-maintenance choice.
How to choose
- Match power to material. 0.8 kW covers plastics, foam and light engraving; 1.5 kW handles MDF and plywood at moderate feed; 2.2 kW is for hard wood and light aluminium work.
- Collet follows tool shank. ER11 accepts up to about 7 mm; move to ER20 above that, which in practice means the 2.2 kW models.
- Check the supply. 110 V models draw roughly 1.5× the current of their 220 V equivalents - 9.0 A against 6.0 A at 1.5 kW - so cable and breaker sizing must follow the nameplate, not the power rating.
- Leave the fan clear. Coaxial cooling pulls air through the rear cap; mounting the spindle hard against a plate or boxing it in will shorten bearing life.
Typical applications
- Woodworking routers cutting MDF, plywood and solid wood
- Acrylic and PVC engraving
- Sign making and light aluminium profiling
- Retrofit of hobby and entry-level production machines
FAQ
Do I need a water pump for an STF spindle?
No. STF is air cooled. If you later move to a water cooled STZ spindle, a pump, radiator and flow switch become mandatory.
Which VFD matches the 2.2 kW 220 V version?
Any 2.2 kW VFD rated for 7.6 A continuous at 400 Hz. Our HS320 series covers this size directly.
Why does the spindle get hot?
The body dissipates motor losses through the airstream. Warm to the touch is normal in continuous cutting; a sudden rise with a burning smell usually means blocked airflow or a failing rear fan.
Can the spindle run at low speed for long periods?
Air cooling depends on shaft speed to move air through the motor. Below roughly 6 000 rpm the cooling margin drops, so keep low-speed heavy cuts short.
Related products
Pair with our HS320 VFD, STZ water cooled spindle, and ER collets.
Hot Tags: air cooled spindle motor, ER11 spindle, 1.5kW CNC spindle, 2 2 kw spindle vfd, 3 phase frequency drive, cnc spindle for scalability standards, mini cnc spindle, spindle motor 800w, vfd 5 hp
You Might Also Like
Send Inquiry