10" rack mount for Arris Cable Modems

I wanted to rack-mount my cable modem, but these models are slightly taller than 1U, which requires removing the factory enclosure and retaining only the PCB and rear panel. This replacement case is designed for passive cooling, as my rack already provides airflow via four 120 mm fans. Previously, these components were simply stacked on a shelf, so this configuration does not represent a reduction in cooling capability, although it should be noted that the modems do generate some heat.

3D Print Settings

• Material: Overture PLA Pro (PETG or other heat-resistant filament recommended)

• Nozzle Diameter: 0.4 mm

• Layer Height: 0.2 mm

• Supports: None required

• Bridging: Minimal bridging present

I used PLA because I like to live dangerously, but PETG, ASA, or ABS are recommended for improved heat resistance in rack-mounted environments.

Electrostatic Discharge (ESD) Precautions

Electronic components inside the modem are sensitive to electrostatic discharge (ESD), which can cause immediate or latent damage.

Follow these precautions during disassembly and assembly:

• Perform all work on a clean, dry, non-conductive surface.

• If available, wear a grounded ESD wrist strap connected to earth ground.

• Alternatively, frequently touch a grounded metal object to discharge static buildup.

• Avoid working on carpeted surfaces.

• Handle the PCB only by its edges.

• Do not touch component leads, solder joints, or connector pins.

Failure to follow ESD precautions may result in permanent damage to the modem.

Materials Required

1. 1× CAT6 keystone coupler

2. 2× M3 × 4 mm length × 4.5 mm OD heat-set inserts

3. 2× M3 × 6 mm socket head cap screws (SHCS)

4. 1× 12 in (0.3 m) Ethernet patch cable

Tools Required

1. Torx T15 bit or screwdriver (possibly a security Torx)

2. Small flat-blade screwdriver (for prying)

Disassembling the Arris Modem

1. Remove the single Torx T15 screw from the back of the unit.

2. Remove and retain the sticker from the bottom of the modem containing the device serial number and MAC address.

   • Record this information first in case the sticker does not survive removal.

3. Using a small flat-blade screwdriver, depress the four internal tabs located at the top and bottom of the unit while separating the clamshell, working from back to front.

   • These tabs require some force to release. Work carefully to avoid injury if the screwdriver slips.

4. Lift and pull the PCB and rear panel assembly out of the case.

5. Gently release the tabs retaining the light pipe and remove the light pipe from the case.

   • Take note of the light pipe orientation relative to the PCB.

Rack Mount Case Assembly

1. Apply the sticker from the original case to the bottom side of the PCB.

   • Choose a flat area with no SMD components or through-hole leads.

   • The sticker will be readable through the holes in the rack case once assembled.

2. Install 2× M3 × 4 mm × 4.5 mm OD heat-set inserts into the bottom half of the rack case.

3. Install the light pipe into the bottom half of the rack case by rotating it into place underneath the retaining tabs.

   • Do not attempt to deflect the tabs in this design, as doing so may break the tabs or the light pipe.

4. Install the PCB into the top half of the rack case by sliding the modem’s rear panel into the rear opening of the case.

   • The rear panel should be loosely retained, with no visible gap between the case and the modem back panel.

5. Carefully bring the two case halves together, ensuring the LEDs slide into position beneath the light pipe.

   • No force should be required. If binding occurs, stop and reassess.

   • The shadow line between case halves may require minor alignment.

6. Install 2× M3 × 6 mm SHCS to secure the case halves together.

7. Install 1× CAT6 keystone coupler into the front of the case.

   • Connect a short Ethernet patch cable from the coupler to the modem’s Ethernet port.

Attribution

This design was informed by and builds upon concepts, dimensions, and general layout ideas from the following community projects:

• Arris Surfboard SB8200 Rack Mount
  https://www.printables.com/model/125437-arris-surfboard-sb8200-rack-mount

• 1U Ventilation Panel for 10" Rack
  https://makerworld.com/en/models/1293799-1u-ventilation-panel-for-10-rack#profileId-1324456

Many thanks to the original creators for sharing their work with the community.