Tenshock GDM1520B Planetary Gear 4.75:1 135g

Tenshock GDM1510B Planetary Gear Drive Motor – 1KW Power, Precision, and Performance without the price tag.

The Tenshock GDM1520B is a game-changing planetary gear drive motor that delivers 1 KW of premium performance at a fraction of the cost. Featuring a compact, ultra-efficient 4.75:1 planetary gearbox paired with a high-performance brushless inrunner motor, it punches well above its weight—matching the output and reliability of systems priced three times higher.

Designed for pilots who demand exceptional performance, smooth operation, and easy maintenance, the GDM1520B offers all the advantages of a geared setup - without breaking the bank.

Engineering highlights

• All-metal 3-planet gearbox – shot-peened steel gears and needle-roller planet carriers for ISO class-6 concentricity and long life under 50 A burst loads.
• High-density 15 mm inrunner – 0.1 mm laminations and N35SH magnets keep core losses low at 50 k RPM.
• CNC-machined 6061-T6 case – ribbed exterior for efficient heat shedding without excess mass.
• 30mm motor diameter and 24mm front flange diameter allowing installation in the narrowest of fuselages.
• Field-replaceable gearset – front cover removes with four screws; a full rebuild averages <10 minutes.

Typical applications
3m - 4m F5J ballasted sailplanes needing sub-140 g front ends and 3 kg+ launch thrust (or 2kg thust with 130 kph pitch speed).
2m - 3m Hotliners needing 1KW powertrains
F3G / GPS-light models on 4S - 5S LiPo where climb rate matters most.
High-performance sport gliders or electric retrofits where nose ballast can be replaced by power.

What you get
GDM1520B motor with factory-installed 4.75 : 1 gearbox
Hardened 5 mm output shaft (flat-ground)
Mounting screws and hex key
PDF data sheet & maintenance guide (download)

At much less than half the cost of premium gear drives—and weighing less than many direct-drive outrunners—the Tenshock S-GDM1520B delivers competition-ready punch without punishing your budget or wing loading. Drop it in, spool it up, and watch your model rocket skyward.

(c) 2025 Neil Stainton