> For the complete documentation index, see [llms.txt](https://docs.revrobotics.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.revrobotics.com/rev-crossover-products/ultraplanetary/features.md).

# UltraPlanetary Features

The REV Robotics UltraPlanetary System includes the following features:

* Three different gear ratio cartridges providing twenty-seven gear ratios ranging nominally from 3:1 to 125:1.
* Pre-assembled cartridges for superior performance and ease of use.
* Flexible output allowing for the designer to choose shaft length or mounting driven parts directly to the output stage.

## Cartridge Features

The REV Robotics UltraPlanetary Cartridges are nominally 10mm thick and made of a plastic (reinforced nylon) molded ring gear with hardened steel planet and sun gears. Cartridges are pre-assembled and lubricated allowing for more time for iterating designs rather than assembling individual stages of gearbox. Check individual CAD Models for exact dimensions for each cartridge.

<figure><img src="/files/60tQ7ZZcC22zBnRYVo39" alt=""><figcaption></figcaption></figure>

**Alignment Ribs:** Protrusions on the input side of the cartridge to help seat stages of the system together.

**Assembly Holes:** M3 assembly holes for attaching cartridges to input and output stages.

**Input Gear:** Sun Gear with a sliding fit for a 13 tooth, M0.55, gear.

**Output Gear:** 13 tooth, M0.55, carrier gear.

Each cartridge was designed with reliability, durability, and ease of use in mind while having a variety of output ratios when used in combination. Cartridges are referred to at the gear ratio of their closest whole number. For exact gear ratios of individual stages see [Cartridge Details](/rev-crossover-products/ultraplanetary/cartridge-details.md#cartridge-details).

## Output Stage Features

The REV Robotics UltraPlanetary Output Stage V2 (REV-41-1615) is nominally 17mm thick with 6mm protruding from the casing for output motion. The Output Stage is pre-assembled and made of a plastic (reinforced nylon) molded body with a ball bearing carrying the load of the Female Output Gear. Check the CAD Model for exact dimensions of the Output Stage.

<figure><img src="/files/FIu7pbOE8TpMVQmeAf9k" alt=""><figcaption></figcaption></figure>

**Alignment Ribs:** Protrusions on the input side of the output stage to help seat stages of the system together.

**Assembly Holes:** M3 assembly holes for attaching the output stage to cartridge and input stages.

**Input Gear:** Piece with sliding fit for a 13 tooth, M0.55, gear.

**Female Output Gear:** Female 5mm hex output for custom length shafts. Motion pattern present for directly attaching sprockets, gears, structure, and wheels.

{% hint style="danger" %}
When directly attaching Motion Components to the Output Stage, remove the set screw from the 5mm Hex Output
{% endhint %}