Photo&Video

A Teardown of the HF49125 bldc motor

Long submersions, continuous duty, a simple drive — take the inrunner and accept 1.22 W/g.

Why One Motor Hums and Another Whines

Three noise sources only: electromagnetic, bearing, aerodynamic. A coast-down test rules out two of them.

900 W Inside a Φ41 Sealed Housing

The part is HS-FS41105 — Φ41 × 105 mm, 900 W continuous, 1600 W peak, IP68, 6-pole, Class F insulation, 650 g. For that envelope, a 900 W rating is not a conservative claim. Every figure below either

Brushless saves 20–30% over brushed

60 °C on the housing：Is it burning up?

Magnets, electrolytics and grease often die before the winding. Demagnetisation is permanent.