Stepper Gear Motor 28/35/42 mm With Planetary Gearbox

Stepper Gear Motor 28/35/42 mm With Planetary Gearbox
Stepper gear motor structure with planetary reducer
HLTNC 28BYG stepper gear motor NEMA 11
HLTNC 35BYG stepper gear motor NEMA 14

Stepper Gear Motor 28/35/42 mm With Planetary Gearbox

Name: Stepper Gear Motor 28/35/42 mm Planetary Gearbox | HLTNC
Brand: HLTNC
SKU: 320749368

Stepper gear motor combining a 1.8 degree hybrid stepper with an integrated planetary gearbox in 28, 35 and 42 mm frames. Ratios from 3.7:1 to 720:1, holding torque from 240 mN.m to 420 N.m.

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Product Introduction

Overview

HLTNC stepper gear motors pair a 1.8° hybrid stepper motor with an integrated planetary gearbox in a single housing. Three frame sizes - 28 mm (NEMA 11), 35 mm (NEMA 14) and 42 mm (NEMA 17) - cover holding torque from 240 mN·m on a single-stage 28 mm unit up to 420 N·m on a four-stage 42 mm unit. They are built for low-speed, high-torque positioning where a bare stepper would stall or lose steps: Z axes on routers, feed rollers, valve actuation and lab automation.

Standard gearboxes offer 1 to 4 stages with ratios from 3.7:1 to 720:1; precision gearboxes offer 3:1 to 50:1 with tighter backlash for indexing duties. Non-standard shafts, cables and ratios can be customized.

Stepper gear motor 28/35/42 mm size comparison

Model range

Model	Frame size	Motor body height	Step angle
28BYG2XX618S1R1.8	28 mm / NEMA 11	32 mm, 52 mm	1.8°
35BYG2XX819S1R1.8	35 mm / NEMA 14	25.5 mm, 36 mm, 48 mm	1.8°
42BYG2XX819S1R1.8	42 mm / NEMA 17	40 mm, 48 mm, 60 mm	1.8°
42BYG2JXX8211.8	42 mm / NEMA 17	40 mm, 48 mm, 60 mm	1.8°

Stepper gear motor planetary reducer structure

Holding torque by stage and motor size

Torque values are the achievable holding torque range for each stage at the given motor body height. A four-stage unit multiplies torque roughly 30–50× over the same motor without a gearbox, at the cost of output speed.

Stage / ratio	28-32	28-52	35-25.5	35-36	35-48	42-40	42-48	42-60
1 stage · 3.7, 5.18	240–340 mN·m	370–520	520–730	850–1200	1200–1660	1500–2200	1800–2600	2200–3220
2 stage · 14, 19, 27	910–1780	1400–2700	1960–3800	3220–6210	4500–8600	5600–10800	7000–13500	8400–16000
3 stage · 51, 71, 99, 139	3320–9100	5100–14000	7100–19500	11700–32000	16320–44500	20500–56000	25500–70000	30000–84000
4 stage · 189 to 720	12350–46800	18900–72000	26500–100800	43500–165600	60500–230000	76000–288000	95000–360000	114000–420000
Precision 1 stage · 3, 4, 5, 10	-	-	-	-	-	1200–4000	1500–5000	1800–6000
Precision 2 stage · 15, 20, 30, 50	-	-	-	-	-	4500–20000	7500–25000	9000–30000

Torque in mN·m. Precision gearboxes are available on 42 mm frames only. Above the gearbox rated load, the gearbox maximum load governs.

Dimensions and weight

Stage	Gearbox height, 28 / 35 / 42 mm	Unit weight
1 stage	29 / 32 / 29 mm	180–505 g
2 stage	37 / 40 / 37 mm	210–550 g
3 stage	44 / 47 / 44 mm	235–605 g
4 stage	52 / 55 / 52 mm	260–700 g
Precision 1 stage	42 mm frame only: 44 mm	455–585 g
Precision 2 stage	42 mm frame only: 54 mm	515–650 g

42BYG stepper gear motor parameter table

How to choose

Start from load torque, not motor size. Multiply your required torque by a 1.5–2× safety factor, then read the table backwards to find the smallest frame that still fits your envelope.
Then pick the ratio for speed. Output speed = input speed ÷ ratio. A 3.7:1 unit keeps most of the motor's speed; a 720:1 unit gives high torque but only a few rpm.
Choose standard or precision. Standard stages are enough for transport and feed axes; precision stages (3:1–50:1, 42 mm only) suit indexing and repeatable positioning.
Check the gearbox height. A four-stage unit adds 52 mm behind the motor - confirm this fits before specifying.

Typical applications

Z axis and A axis on small CNC routers and laser cutters
Filament feed and bed lift on 3D printers
Conveyor and packaging line speed reduction
Valve and damper actuation in HVAC and water treatment
Lab automation, dispensing and sample handling

FAQ

What is the difference between 28BYG, 35BYG and 42BYG?

The number is the motor frame size in millimetres: 28 mm (NEMA 11), 35 mm (NEMA 14) and 42 mm (NEMA 17). Larger frames carry more torque for the same gear ratio.

Can I order a custom ratio or shaft?

Yes. Non-standard ratios, shafts, connectors and cable lengths can be customized; the drawing is confirmed before production.

What is the step angle?

1.8° per full step, i.e. 200 steps per revolution at the motor. The gearbox divides output speed by the ratio and multiplies torque accordingly.

Do I need a microstep driver?

The motors run with any 2-phase bipolar driver rated for the motor current. Microstepping improves smoothness at low speed but does not increase holding torque.