CHIHAI GM25-310T Covered Hall Encoder Gear Motor, 7.4V and Wheel Kits

OverviewThe CHIHAI MOTOR CHR-GM25-310T ABHL DC gear motor combines a 25 mm metal gearbox, a 7.4 V brushed motor and an 11 PPR Hall encoder protected by a rear cover. Choose the motor with lead, add a mounting bracket, or select the bracket and 65 mm yellow wheel kit. The reduction ratio and no-load speed form a separate selection.Features Metal reduction gears and copper armature winding. 4 mm D-shaped output shaft for mechanical coupling. AB quadrature Hall feedback for rotation measurement with a compatible controller. Rear cover protects the encoder assembly from accidental contact; no waterproof or IP rating is claimed. Forward and reverse motor operation by reversing motor polarity after stopping. Specifications Brand / model CHIHAI MOTOR / CHR-GM25-310T ABHL Motor supply 7.4 V DC; permanent-magnet brushed motor Gear train Metal reduction gears, copper motor winding Gearbox / motor diameter 25 mm gearbox; 24.4 mm motor body drawing reference Output shaft 4 mm D shaft; 3.5 mm across-flat reference; 12 mm projection; 8 mm D-flat length Front mounting Two M3.0 x 2 tapped holes, 17 mm spacing; 7 mm boss and 2.5 mm shoulder reference Rear covered section 28.5 mm motor / rear-cover section; total body length also depends on gearbox L Motor mass Approximately 70 g; varies with gear reduction; accessories and shipping packaging additional Encoder AB dual-channel incremental magnetic Hall encoder with rear protective cover Encoder supply 3.3 V DC or 5 V DC, separate from motor supply Feedback 11 PPR base at motor shaft; output pulse reference = 11 x actual reduction ratio Magnetic ring 22 poles / 11 pole pairs Encoder response 100 kHz reference; A/B square-wave signals with onboard pull-up / shaping resistors Connector PH2.0-6PIN with matching lead Motor current No-load <=200 mA at 4.4/9.3:1, <=180 mA at other table ratios; rated <=0.65 A; stall <=1.4 A Gearbox torque ceiling 9 kgf.cm; stall torque is not a continuous operating rating Reduction, Speed and LoadThe selectors use nominal rounded ratios. Their engineering ratios are 4.4, 9.3, 15.46, 20.41, 34.01, 44.9, 74.83, 98.78, 164.63 and 217.31:1 for the respective 4, 9, 15, 20, 34, 45, 75, 100, 165 and 217 selections. Use the 7.4 V figures below to distinguish no-load speed from the rated load point. The 362.18 and 478.08:1 rows are family references, not additional purchasable options. Engineering ratio :1 No-load rpm Rated rpm Rated kgf.cm Stall kgf.cm / limit Output pulse reference Gearbox L mm Gear stages 4.4 2100 1470 0.1 >=0.25 48.4 19 2 9.3 1000 700 0.2 >=0.5 102.3 19 3 15.46 600 420 0.3 >=0.8 170.06 19 4 20.41 450 325 0.4 >=1.0 224.51 19 4 34.01 275 190 0.7 >=1.5 374.11 21 5 44.9 205 145 0.9 >=2.0 493.9 21 5 74.83 125 110 1.5 >=3.5 823.13 23 6 98.78 95 80 2 >=5.0 1086.58 23 6 164.63 56 40 3 >=7.5 1810.93 25 7 217.31 43 30 4 9 maximum gearbox limit 2390.41 25 7 362.18 25 18 7 9 maximum gearbox limit 3983.98 27 8 478.08 19 14 9 9 maximum gearbox limit 5258.88 27 8 Hall output pulse references use the actual gear ratio and 11 base pulses per motor revolution. Pulse counting depends on the decoder edge-count convention; do not assume these values already include quadrature multiplication. Maximum permitted gearbox torque is 9 kgf.cm. Stall values are not continuous ratings; avoid overload and stalled operation.Encoder Wiring and Power Wire color Signal Function White M2 - Motor negative Blue VCC Encoder supply 3.3 V or 5 V Green C2 / B Encoder phase B signal Yellow C1 / A Encoder phase A signal Black GND Encoder ground Red M1 + Motor positive Connect the 7.4 V motor supply through red/white and the separate 3.3 V or 5 V encoder supply through blue/black. Green and yellow are signal outputs. Keep motor voltage away from logic pins. Verify connector orientation and compatible input levels before connection; wire colors identify functions rather than an inferred connector pin order. A motor driver and feedback controller are required separately for controlled motion.Mechanical FitAllow clearance for the selected gearbox length and the rear encoder cover. Shaft projection is 12 mm and the D-flat length is 8 mm. Check shaft fit, the 17 mm mounting spacing and screw engagement before assembly; screws must not enter the gear train. The original engineering drawing is retained below so dimensions and geometry can be checked before machining.ApplicationsCompact robots, balancing-vehicle prototypes, motorized smart-home mechanisms, appliance drives and lock mechanisms where the selected speed, torque, mounting and encoder interface meet the design requirements. Balancing operation requires a suitable chassis, driver, sensors and control software supplied separately.What's Included Covered Hall Encoder Motor: one selected-ratio motor with rear cover and matching six-wire lead. Motor + Mounting Bracket: the covered encoder motor and lead, one bracket and pictured mounting screws. Motor + Bracket + 65mm Yellow Wheel Kit: the covered encoder motor and lead, one bracket, one yellow 65 mm basic wheel, coupling and pictured screws / hex key. Each selection supplies one motor. A wheel is included only in the yellow wheel kit. No power supply, motor driver, MCU, feedback controller or complete vehicle is included.Installation and OperationUse the rated 7.4 V motor supply and verify wiring before power-up. Avoid sustained stall, overload and rapid reversal. Reducing drive voltage can reduce available torque as well as speed; speed and gear noise vary with load and ratio. Keep rotating shafts and mounting hardware clear of the encoder cover and wiring.FAQIs the encoder voltage also 7.4 V?No. The motor uses 7.4 V, while the Hall encoder requires a separate 3.3 V or 5 V supply.Does every option include a wheel?No. Only the 65 mm yellow wheel kit includes a wheel, bracket and coupling.Does 11 PPR describe the output shaft?It is the base motor-shaft pulse reference. Multiply by the actual gear ratio for the output-shaft reference, then account for your decoder's counting convention.Visual DetailsOriginal front mounting drawing: 17 mm spacing and two M3 tapped holesGM25-310T mechanical dimensionsHall encoder - wiring and signal reference7.4 V performance reference - 17.4 V performance reference - 2Covered Hall motor - package selection