> 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/ion-build/build-guides/maxplanetary-gearbox-assembly/shaft-retention-assembly.md).

# Shaft Retention Assembly

The MAXPlanetary Base Kit comes with a 3in long rounded 1/2in hex shaft with a 10-32 tapped hole at either end. This shaft can be retained in the MAXPlanetary 1/2in Socket Hex Output with a screw installed from the back side before assembling the rest of the gearbox.

In addition to the included hex shaft, additional lengths of pre-tapped shaft are available from REV. Also, any length of team-provided 1/2in hex shaft (with or without rounded corners) can be retained in the output provided that it has a 10-32 tapped hole.

## Assembly Instructions

For assembly you will need a 1/8" Allen Wrench. 

|                                                                                                                                                                                                                                                                               |                                                                            |
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| 1) Line up the hex of the shaft and the output block.                                                                                                                                                                                                                         | ![](/files/YcJLVxTVsZBbFwQhGohZ)                                           |
| <p>2) Insert the hex shaft in the output.  Ensure that the shaft bottoms out in the socket.  </p><p></p><p><strong>Note: If the shaft has been cut, ensure that any burrs have been removed from the cut end, so that the shaft will fit in the output properly.</strong></p> | ![](/files/J0pfGHIdjotiV2z1Mi07)                                           |
| <p>3) Apply thread-locking compound to the 1/2in long Button Head Cap Screw (included in the MAXPlanetary Base Kit or Hardware Kit).  </p><p></p><p><strong>Note: We recommend Loctite 243 (commonly known as “Blue Loctite”).</strong></p>                                   | <p><img src="/files/oeydGrUpquXz0F1ob6Rx" alt=""></p><p>\*not to scale</p> |
| <p>4) Insert the button head screw into the back side of the output.  </p><p></p><p><strong>Note: This is typically easiest with a hex key or t-handle WITHOUT a ball end.</strong></p>                                                                                       | ![](/files/Ri2ddF9rBeo0uy7Yi4s8)                                           |
| 5) Tighten down the screw into the threads in the end of the output shaft.                                                                                                                                                                                                    | ![](/files/TquIxyJiwQ6DOVFChqtE)                                           |

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