EMAX ECO II 3210

What it pulls

EMAX’s own bench test, one line per prop. Drag across the chart to move the throttle; the model above follows.

What you get

• 4.4 kg at 32 V

  At 32 V the 900KV pulled 4,378 g at full throttle on an HQ8045 three-blade, drawing 70.55 A.

  Source: EMAX USA product page

• 6.9 g/W at 30% throttle

  On a 10-inch HQ1050 at 25 V the 800KV made 492 g at 30% throttle, at 6.91 g/W.

  Source: EMAX USA product page

• One housing, four windings

  All four KVs share the 99 g, φ39.1 × 45.8 mm housing, the 6 mm bearing shaft, the M5 prop thread and the 19 × 19 mm M3 mount.

  Source: EMAX USA product page

What to pair it with

Our reading of EMAX’s numbers, so your build matches what the motor was tested with.

ESC

EMAX’s peak currents, each the top of that KV’s bench tests, run from 59.4 A (800KV) to 88.6 A (1200KV). An 80 A ESC covers the 800KV to 1050KV; the 1200KV needs one rated for about 90 A. (EMAX USA product page)

Props

8 to 10-inch for the 800KV, 8 to 9-inch for the 900KV and 1050KV, 8-inch for the 1200KV. EMAX tested them on 8, 9 and 10-inch three-blades and an 8-inch two-blade. (EMAX USA product page)

Battery

6S–8S for the 800KV and 900KV, 6S for the 1050KV and 1200KV; EMAX ran its tests at 25 V and 32 V. (EMAX USA product page)

Frame

Four M3 holes, 19 × 19 mm; four M3×10 screws and an M5 nylock nut come in the box. (EMAX USA product page)

Where to buy

• EMAX USAthe maker’s US store; same price for every KV (all listed as sold out)
  $48.99seen Oct 19, 2026
  Visit
• EMAXthe maker’s global store; all four KVs (all listed as sold out)
  $75.44seen Oct 19, 2026
  Visit

Plain links, not affiliate links. Prices change; the store’s page has the current one.

Full specs

Bench data

Redrawn from EMAX’s test reports. Thrust is static pull on a bench, more than you get in flight. Power is volts × amps; efficiency is thrust divided by power.

Inside the motor

A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:

• Shaft. Steel, M5 thread (CW); 6 mm through the bearings. (EMAX USA product page)
• Bell. Ventilated, anodised. (EMAX USA product page)
• Stator. The coils are wound on a stack of thin steel laminations: 32 × 10 mm (3210). (EMAX USA product page, EMAX product page)
• Winding. Multi-strand. (EMAX USA product page)
• Base. 4 × M3 holes, 19 × 19 mm. (EMAX USA product page)

How fast it spins

KV is the motor’s no-load speed per volt. With nothing on the shaft, the 900KV version reaches about these speeds; a prop loads the motor and brings it down, typically to around 70–75% of these figures at full throttle.

A 14-pole rotor has 7 pole pairs, so every turn of the shaft is 7 electrical cycles, and a six-step ESC switches the phases 42 times per turn.

About the 3D model

A generic outrunner drawn from EMAX’s published sizes: the 32 × 10 mm stator, 39.1 mm bell, 5 mm shaft, 19 mm mounting circle and 12 teeth and 14 magnets. Anything EMAX doesn’t publish is typical for a motor this size, and the bell’s spoked top, the base and the inside are a generic design, not this motor’s. The colours are read off the maker’s product photos. There are no logos or markings: it is our drawing, not the maker’s.

Sources

1. EMAX USA: EMAX ECO II 3210 Brushless Motor (product page, with the spec table and EMAX’s load-test tables for each KV and prop, 30% to 100% throttle, at 25 V or 32 V, with the measured voltage on each row). Retrieved Oct 19, 2026.
2. EMAX: ECOII 3210 800KV 900KV 1050KV 1200KV (product page on EMAX’s global store, with the same description and tables). Retrieved Oct 19, 2026.