HappyModel EX1404

What you get

• Bench data for each KV

  HappyModel publishes 14.8 V tables with Gemfan 3018, 4023 and 4024 props; the 3500KV pulls 338.3 g with the 4024.

  Source: HappyModel product page

• Three KVs

  2750KV for 4S, 3500KV for 3S–4S, 4800KV for 3S.

  Source: HappyModel product page

• 8.7 g

  HappyModel lists 8.7 g per motor; the leads are 130 mm long and end in a plug.

  Source: HappyModel product page

What to pair it with

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

ESC

HappyModel's bench tops out at 9.8 A (4800KV, Gemfan 3018), 9.5 A (3500KV, Gemfan 4023) and 5.9 A (2750KV, Gemfan 4023), all at 14.8 V. A 4S-rated ESC of 12 A or more per motor covers them. (HappyModel product page)

Props

HappyModel tested Gemfan 4024 two-blade and 4023 three-blade props on the 2750KV and 3500KV, and the Gemfan 3018 two-blade on the 3500KV and 4800KV. (HappyModel product page)

Battery

4S for 2750KV, 3S–4S for 3500KV, 3S for 4800KV (HappyModel's bench still runs it at 14.8 V). (HappyModel product page)

Frame

Four M2 screws on a 9 mm circle. (HappyModel drawing)

Where to buy

• RaceDayQuads3500KV
  price on the store’s page
  Visit
• WREKD3500KV
  price on the store’s page
  Visit
• GetFPV2750KV, 3500KV or 4800KV
  price on the store’s page
  Visit

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

Full specs

Bench data

Redrawn from HappyModel’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:

• Bell. The top has 12 windows and four M2 holes on a 5 mm circle round the 1.5 mm shaft. (HappyModel drawing)
• Base. 2 mm thick at the four M2 holes; the three leads run 130 mm to a plug. (HappyModel drawing)

How fast it spins

KV is the motor’s no-load speed per volt. With nothing on the shaft, the 3500KV 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 HappyModel’s published sizes: the 14 × 4 mm stator, 17.8 mm bell, 12.2 mm height, 1.5 mm shaft, 9 mm mounting circle and 9 teeth and 12 magnets. Anything HappyModel 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. HappyModel: EX1404 KV2750 KV3500 KV4800 brushless motor (product page, spec list and bench data; where a table lists two readings at its top throttle setting the first is kept, and the throttle column, in unstated units up to 2200, is left out). Retrieved Oct 19, 2026.
2. HappyModel: EX1404 dimension drawing (image on the product page). Retrieved Oct 19, 2026.
3. HappyModel: EX1404 main product photo, used for finish. Retrieved Oct 19, 2026.