Robot joints and actuation
50.9:1 planetary reduction trades motor speed for torque at a joint or drive, through a 8 mm output shaft.
Engineering inference
goBILDA
goBILDA 5103 Planetary Gearbox 50.9:1
goBILDA 5103-0024-0051 5103-series 3-stage planetary gearbox, 50.9:1 (exactly 50.895:1), steel gears, sold as the replacement gearbox for 5203 Yellow Jacket motors: Ø36 mm × 50.3 mm body, 8 mm REX output shaft 23.5 mm long, M4 goBILDA pattern on the face, 234 g. No torque or backlash rating is published.
5103-0024-0051Development boardPrice$34.99www.gobilda.com · in stock
Buy at www.gobilda.com Overview
Motor essentials
Facts about the complete product. Unknown values remain open design questions.
- Gear reduction
- 50.9:1
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)
- 36 × 36 × 50.3 mm
- Verification
- generated
- Envelope complete
- Yes
Ratio & output
Ratio, torque and output
What the gearbox multiplies and what it bolts to.
- Reducer type
- planetary
- Gear ratio
- 50.9:1
- Stages
- 3
- Input
- replaces the gearbox on goBILDA 5203 Yellow Jacket motors (RS-555 motor, input pinion)
- Output shaft
- 8 mm REX, 24 mm long
- Output shaft diameter
- 8 mm
- Weight
- 234 g
Rated output torque is continuous; peak is short-duration. Backlash is measured at the output.
Specifications
Motor performance
No-load, rated-load and stall figures retain their separate test conditions.
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
- 36 mm
- Width
- 36 mm
- Reported height / thickness
- 50.3 mm
Attached generated geometry is an approximate envelope. A generated outline does not establish an electrically verified PCB footprint.
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.gobilda.com
US · USD
$34.99Minimum quantity unknown
- Observed stock
- in stock
- Checked
- Oct 1, 2026, 05:35 PM 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
goBILDA 5103-0024-0051 50.9:1 planetary gearbox with input adapter and pinion (render) (opens in a new tab)
Manufacturer reference
maker render (50.9:1): black gearbox body, 8 mm REX output, input adapter plate and pinion
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.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.other.weight_g, spec.provides.features, spec.provides.gear_ratio, spec.provides.input_interface, spec.provides.output_shaft, spec.provides.output_shaft_diameter_mm, spec.provides.reducer_type, spec.provides.stages, spec.usage.pinout_complete
sha256 7f416f3d1a17110fb0ed1c0823730f3110ccb71a7d389715af4e7867c113f8ee
Supports: offers
FAQ
goBILDA 5103 Planetary Gearbox 50.9:1 questions
How much does the goBILDA 5103 Planetary Gearbox 50.9:1 cost?
From $34.99 at www.gobilda.com. Prices are observed unit prices before tax and shipping.
What are the goBILDA 5103 Planetary Gearbox 50.9:1 dimensions?
36 × 36 × 50.3 mm. A STEP model is available for enclosure fit checks.
Where does this goBILDA 5103 Planetary Gearbox 50.9:1 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.