> 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/max-180-degree-gearbox-assembly.md). # MAX 180 Degree Gearbox Assembly The 180 Degree Output can be assembled with two different Ratios, a 1:1 ratio for balance output and a 2:1 Ratio when more torque is needed. The two Ratios require separate assemblies, both are detailed below. ## 1:1 Ratio Assembly | 1) Add two 8mm Shaft Spacers to the NEO Brushless Motor output shaft. |

| | 3) Slide the 1/2 Hex Shaft Adapter to the NEO output shaft. |

| | 4) Fasten the base plate to the NEO using the left holes in the base plate and two #10-32 x 1/2in screws with a 1/8in Allen Key. |

| | 5)Press a Flanged Bearing into the base with the flanged side opposite of the NEO. |

| | 6) Press a 1/2in Hex Through Bore Shaft into the Flanged Bearing. |

| | 7) Slide a 1/8 MAXSpline Spacer onto the 1/2in Hex Through Bore Shaft. |

| | 8) Screw together two MAXSpline Pulley halves with six M3x12mm screws. |

| | 9) Screw together two MAXSpline to 1/2 Hex Adapter halves with two #12-32x1/2in Socket Head screws with a 5/32in Allen Key. |

| | 10) Screw together two MAXSpline Pulley halves with six M3x12mm screws. |

| | 11) Place the 48-tooth RT25 Belt around both the NEO Pulley and MAXSpline Pulley, then slide them onto the Output Shaft of the NEO and 1/2in Hex Through Bore Shaft at the same time. |

| | 12) Secure the NEO Pulley with a Retaining Ring. |

| | 13) Slide a 1/8 and a 1/16 MAXSpline Spacer onto the 1/2in Hex Through Bore Shaft. |

| | 14) Press a Bearing onto the 1/2in Hex Through Bore Shaft. |

| | 15) Press the Pulley Cover Plate onto the 1/2in Hex Through Bore Shaft Bearing. |

| | 16) Secure the Pulley Cover Plate with three #10-32 x1-1/2in screws and #10 Spacers using a 1/8in Allen Key. |

| ## 2:1 Ratio Assembly | 1) Fasten the base plate to the NEO using the right holes in the base plate and two #10-32 x 1/2in screws with a 1/8in Allen Key. |

| | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------- | | 2)Press a Flanged Bearing into the base with the flanged side opposite of the NEO. |

| | 3) Press a 1/2in Hex Through Bore Shaft into the Flanged Bearing. |

| | 4) Slide a 1/8 MAXSpline Spacer onto the 1/2in Hex Through Bore Shaft. |

| |

5) Press a Retaining Ring onto the the Output Shaft of the NEO.

Please Note: You will adjust this placement later in step 7.

| | 6) Screw together two MAXSpline Pulley halves with six M3x12mm screws. |

| |

7) Place the 40-tooth RT25 Belt around both a 12tooth-RT25 Pulley and MAXSpline Pulley, then slide them onto the Output Shaft of the NEO and 1/2in Hex Through Bore Shaft at the same time.

Please Note: Adjust the Retaining Ring on the shaft of the NEO to make the 12tooth-RT25 pulley level with the MAXSpline Pulley.

| | 8) Secure the 12tooth-RT25 Pulley with a second Retaining Ring. |

| | 9) Slide a 1/8 and a 1/16 MAXSpline Spacer onto the 1/2in Hex Through Bore Shaft. |

| | 10) Press a Bearing onto the 1/2in Hex Through Bore Shaft. |

| | 11) Press the Pulley Cover Plate onto the 1/2in Hex Through Bore Shaft Bearing. |

| | 12) Secure the Pulley Cover Plate with three #10-32 x1-1/2in screws and #10 Spacers using a 1/8in Allen Key. |