Mobile robot drive trains
25 mm 12 V MP gearmotor at 172:1 with a built-in quadrature encoder — closed-loop drive for small and mid-size wheeled robots.
Engineering inference
Pololu
Pololu #4868 172:1 25D Gearmotor MP 12V
Pololu #4868 is a 12 V medium-power (MP) brushed DC 25D metal gearmotor with 171.79:1 spur reduction: 46 rpm and 0.10 A no-load, 18 kg·cm / 1.8 A stall (extrapolated), 31 % peak efficiency, Ø25 mm × 71 mm, 4 mm D-shaft 12.5 mm long, two M3 face holes, 107 g, and a 48 CPR Hall quadrature encoder on the motor shaft (8245.92 counts per output revolution).
4868MotorPrice$53.95www.pololu.com · in stock
Buy at www.pololu.com Overview
Motor essentials
Facts about the complete product. Unknown values remain open design questions.
- Rated voltage
- 12 V
- No-load speed
- 46 RPM
- Stall torque
- 1.7652 N·m
- Gear reduction
- 171.79:1
- Shaft diameter
- 4 mm
- Encoder
- Hall quadrature encoder; 48 CPR at the motor shaft, 8245.92 CPR at the output shaft
A good fit for
Guidance to help you shortlist. The basis is shown for each recommendation.
No-load speed, rated performance and stall limits describe different operating points. A stall specification is not a continuous operating rating.
3D model & CAD
3D model & CAD files
Generated from the datasheet's dimensioned drawing and measured against it. Download the STEP to check fit in your own enclosure.
- Envelope (L × W × H)
- 25 × 25 × 83.5 mm
- Verification
- generated
- Envelope complete
- No — some heights assumed
shaft_flat_len=10 mm assumed: D-flat length not dimensioned; 10 mm assumed for the CAD envelope only
Mechanical interface
Mechanical output interface
The motor body, transmission and output shaft have separate roles in a mechanism.
- Motor type
- gearmotor
- Gear reduction
- 171.79:1
- Shaft diameter
- 4 mm
- Body diameter
- 25 mm
- Body length
- 71 mm
- Encoder
- Hall quadrature encoder; 48 CPR at the motor shaft, 8245.92 CPR at the output shaft
Reported body dimensions may exclude the shaft, terminals and other protrusions. Use the manufacturer drawing to establish the complete mounting and clearance envelope.
Specifications
Motor performance
No-load, rated-load and stall figures retain their separate test conditions.
- Rated voltage
- 12 V
- No-load speed
- 46 RPM
- No-load current
- 0.1 A
- Stall torque
- 1.7652 N·m
- Stall current
- 1.8 A
Stall torque and current are not continuous ratings. Check the duty cycle and starting load when choosing the driver and power supply.
Thermal limits by level
Product operating conditions, chip ambient ratings, package case limits and junction maxima remain separate.
Motor body
Mechanical dimensions
Reported product dimensions may exclude protruding components. Unknown height does not establish a complete clearance envelope.
- Length
- 25 mm
- Width
- 25 mm
- Reported height / thickness
- 83.5 mm
- Mounting hole records
- 2
Attached generated geometry is an approximate envelope. A generated outline does not establish an electrically verified PCB footprint.
Board connectors
| ID / type | Pins | Pitch | Notes |
|---|---|---|---|
| motor_encoder1x6 female header, 2.54 mm pitch, six 20 cm colour-coded leads | 6 | 2.54 mm | — |
Complete structured record
Every available field, including details beyond the summaries. Null means the value has not been established.
Sourcing & files
Supplier offers
US / USD is the target market. Observed price and stock are separate from a delivery quote.
www.pololu.com
US · USD
$53.95Minimum quantity unknown
- Observed stock
- in stock
- Checked
- Oct 2, 2026, 01:32 AM UTC
- Delivery estimate
- Not quoted
Observed within the last 24 hours. Confirm the current supplier quote.
Visit supplier (opens in a new tab)Delivery depends on quantity, postal code and shipping method. A dispatch statement such as “ship today” is not an arrival estimate.
Design files and references
Each source keeps its own verification status. Confirm the part revision and file contents before using it in a design.
Datasheet (opens in a new tab)
Manufacturer reference
Pololu #4868 172:1 25D gearmotor with encoder (opens in a new tab)
Manufacturer reference
maker product photo (main gallery image)
STEP (generated from datasheet drawing) — link unavailable
Generated asset
cad_check passed
Generated envelope geometry may also exist for this record. It does not replace manufacturer CAD or a verified electrical land pattern.
Source evidence
Document provenance, retrieval dates and the field groups supported by each source.
Supports: spec.constraints.electrical.supply_voltage_nominal_v, spec.geometry.body_diameter_mm, spec.geometry.body_length_mm, spec.geometry.cad.assumptions, spec.geometry.cad.bbox.height_mm, spec.geometry.cad.bbox.length_mm, spec.geometry.cad.bbox.width_mm, spec.geometry.cad.envelope_complete, spec.geometry.cad.mesh_path, spec.geometry.cad.step_path, spec.geometry.cad.verification, spec.geometry.dimensions.height_mm, spec.geometry.dimensions.length_mm, spec.geometry.dimensions.width_mm, spec.geometry.mounting_holes, spec.geometry.other.weight_g, spec.geometry.shaft_diameter_mm, spec.geometry.shaft_extension_mm, spec.geometry.shaft_profile, spec.provides.features, spec.provides.feedback, spec.provides.gear_ratio, spec.provides.motor_type, spec.provides.no_load_speed_rpm, spec.provides.output_type, spec.provides.stall_torque_nm, spec.usage.connectors, spec.usage.pinout, spec.usage.pinout_complete, spec.usage.requirements.driver_required, spec.usage.requirements.no_load_current_a, spec.usage.requirements.rated_voltage_v, spec.usage.requirements.stall_current_a
sha256 a2db2ebd88546f6bdbf0a3e2ee9a45e211151abed10f6748a8839be30a1d4f10
Supports: offers
FAQ
Pololu #4868 172:1 25D Gearmotor MP 12V questions
How much does the Pololu #4868 172:1 25D Gearmotor MP 12V cost?
From $53.95 at www.pololu.com. Prices are observed unit prices before tax and shipping.
What are the Pololu #4868 172:1 25D Gearmotor MP 12V dimensions?
25 × 25 × 83.5 mm. A STEP model is available for enclosure fit checks.
Where does this Pololu #4868 172:1 25D Gearmotor MP 12V data come from?
Every value in this record is traced to a source — 2 documents including the board and chip datasheets — with the page and table cited per value. Unknowns are left explicit, never guessed.