EMAX E3 0702B

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 for $18.46

• 39 g on 1S

  On EMAX’s 4 V bench the 30000KV pulled 39.2 g at full throttle on an HQ 31 mm 1.2 × 1.1 three-blade, drawing 5.82 A (23.28 W).

  Source: EMAX spec sheet and bench tables

• 1.39 g

  EMAX weighs the motor at 1.39 g with its 35 mm, 30 AWG leads.

  Source: EMAX spec sheet and bench tables

• N52SH magnets, single-strand windings

  EMAX’s E3 series uses N52SH arc magnets, single-strand windings and G1 precision bearings in a 7075 aluminium bell.

  Source: EMAX 30000KV page

• Plug-in leads

  The leads end in a 1.25 mm plug, and the base takes three M1.4 screws on a 6.6 mm circle.

  Source: EMAX spec sheet and bench tables

What to pair it with

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

ESC

EMAX gives peak currents of 5.69 A (27000KV) and 5.82 A (30000KV), the most its 4 V bench tests drew. An ESC rated for at least 6 A per motor covers both. (EMAX spec sheet and bench tables)

Props

31 mm (1.2-inch) three-blades: EMAX tested HQ 31 mm 1.2 × 0.9 and 1.2 × 1.1 props and its own Avia 31 mm, which pulled within 3 g of one another at full throttle. (EMAX spec sheet and bench tables)

Battery

1S. EMAX’s bench tests ran at 4 V. (EMAX spec sheet and bench tables)

Frame

Three M1.4 holes on a 6.6 mm circle; four M1.4×2.5 mm screws come in the box. (EMAX spec sheet and bench tables)

Where to buy

• EMAXthe maker’s global store; 30000KV
  $18.46seen Oct 19, 2026
  Visit
• EMAXthe maker’s global store; 35000KV
  $18.46seen Oct 19, 2026
  Visit
• EMAXthe maker’s global store; 27000KV (listed as sold out)
  $16.92seen 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, 1 mm prop shaft standing 3.6 mm above the bell; 1.5 mm through the bearings. (EMAX spec sheet and bench tables, EMAX 30000KV page)
• Bell. 7075 aluminium, anodised. (EMAX 30000KV page, EMAX spec sheet and bench tables)
• Magnets. N52SH arc magnets. (EMAX 30000KV page)
• Stator. The coils are wound on a stack of thin steel laminations: 7 × 2 mm (0702). (EMAX 30000KV page, EMAX spec sheet and bench tables)
• Winding. Single-strand. (EMAX 30000KV page)
• Bearings. G1 precision bearings (EMAX gives no size). (EMAX 30000KV page)
• Base. 3 × M1.4 holes on a 6.6 mm circle. (EMAX spec sheet and bench tables)

How fast it spins

KV is the motor’s no-load speed per volt. With nothing on the shaft, the 30000KV 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 12-pole rotor has 6 pole pairs, so every turn of the shaft is 6 electrical cycles, and a six-step ESC switches the phases 36 times per turn.

About the 3D model

A generic outrunner drawn from EMAX’s published sizes: the 7 × 2 mm stator, 9 mm bell, 8.5 mm height, 1 mm shaft, 6.6 mm mounting circle and 9 teeth and 12 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: E3 Series 0702B-30000KV Brushless Motors (product page on EMAX’s global store, with its specs at a glance). Retrieved Oct 19, 2026.
2. EMAX: E3 Series 0702B-27000KV Brushless Motors (product page on EMAX’s global store). Retrieved Oct 19, 2026.
3. EMAX: E3 Series 0702-35000KV Brushless Motors (product page on EMAX’s global store; it titles the motor 0702 and repeats the 0702B’s specs at a glance). Retrieved Oct 19, 2026.
4. EMAX: E3-0702B motor sheet (image on EMAX’s 27000KV and 30000KV pages): dimension drawing, spec list, spec table for the 27000KV and 30000KV, and bench tables at 4 V on three 31 mm props per KV, by throttle from 20% to “Max”. Retrieved Oct 19, 2026.