Raspberry Pi 4B mount for LGX Casset Patch Panels - Hat Compatible

This is the first of what I think will be several models meant to adapt various SBCs to be mounted to a standard LGX Fiber Cassette Patch Panel. The OnShape Files can be found here:

w/o microSD cut-out

https://cad.onshape.com/documents/80082571a558892aae997efa/w/e55f420de19e4473535507f1/e/744c97433bbe2fe0557fb5d4?configuration=default&renderMode=0&uiState=65f22782b7e1b8607195b62c

w/ microSD cut-out

https://cad.onshape.com/documents/80082571a558892aae997efa/w/e55f420de19e4473535507f1/e/744c97433bbe2fe0557fb5d4?configuration=default&renderMode=0&uiState=65f4fa4cbf5e927931595f9f

I have attached a CSV of the BOM, but I'll paste it here, too:

This model can be used with or without a hat. In my case, I will be installing a POE hat, so that I do not need to run any additional power cables to this RPi.

Features:

• Can be used with or without a hat (see assembly instructions below)
• Clearances around the GPIO pins that stick out from beneath the RPI
• Compatible with any standard LGX Cassette patch panel. Or it should be. If yours doesn't fit, check out the OnShape link, go to the part studio titled “Raspbery Pi 4b LGX Mount” for the 3D printed bracket, and adjust “LGX Mount Clearance” value to appropriate amount to let it clear the opening on your panel.
• Heat-set inserts for secure installation of screws and mounting into the rack.
• Screws can be inserted from above or below the RPi, allowing it to be compatible with either direct mounting, or with the installation of female-female stand-offs.
  • Screws installed from beneath have shallow recesses available to allow the heads to sit flush.

Printing Instructions:

You can probably print this either face-down (as shown in the included gcode), or ‘normally’. Unfortunately, it must be printed with supports no matter how its oriented. I would also recommend you use organic supports, and to increase the top contact Z distance to 0.3mm (0.2mm grips to the model just a little too well still, and 0.4mm allowed some places to print a little too sloppily). You must use 4 or more perimeters when printing this model, using fewer than 4 perimeters does not give enough material for the heat sets to find purchase. Other than that, use whatever in-fill pattern or density that suits you.

Assembly instructions

Post-printing

1. Carefully remove the supports, and check that all 6 of the mounting holes printed without any large deformations
2. Install the heat-set inserts (I recommend 400F for an iron temp for PETG)
   • Take care not to install the inserts too deeply, they should sit flush with their surfaces.
   • Immediately use a non-conductive object to help flatten the inserts prior to the inserts cooling, to help set them as square to the part and smoosh down an plastic that may have risen up around the insert during installation.
3. Move on to one of the Rpi installation methods below:

Without a hat

1. Insert the Raspberry Pi 4 into the model
   • It will be a tight fit to the front cut-outs, particularly for the RJ45 ethernet port. Come in straight at it, and keep gently applying force, and it will slip into the place.
2. Drive in item #4 (Socket button head screw M2.5x0.45 x 6) to each of the mounting holes from above the Raspberry Pi
3. Install the bracket into your LGX patch panel

With a hat

1. Insert the Raspberry Pi 4 into the model
   • It will be a tight fit to the front cut-outs, particularly for the RJ45 ethernet port. Come in straight at it, and keep gently applying force, and it will slip into the place.
2. Drive item #8 (Zinc-Plated Steel Button Head Torx Screws, T8, M2.5 x 0.45 mm Thread, 10 mm Long) into each of the mounting holes from below the Raspberry Pi.
   • You'll be left with 4 screw threads sticking up out of the Raspberry Pi, perfect for threading stand-offs down onto.
3. Install the correct length stand-offs (likely whatever came with the Hat) by threading them down onto the screws
4. Install the Hat onto the GPIO pins
5. Secure the Hat by installing the screws that came with the Hat.
   • I know 5mm long screws fit just fine from experience.
6. Install the bracket into your LGX patch panel

Change log:

• 2024-03-14: Original publication
• 2024-03-15: Added a cut-out to make inserting and removing the microSD card easier/possible without having to remove the board from the mounting plate.