Expansion Bay Module Screw Washer/Standoff

Creators & Developers Expansion Bay
1

Hello,

I’m currently developing / prototyping a custom third-party expansion bay module (to be announced in a future forum post), and I am currently in the process of finalizing the design for the final prototype production run. However, I am having trouble identifying the correct part used to mount the module PCB in the expansion bay case. From what I can tell, these appear to be surface-mount M2 screw washers/standoffs which are the parts actually screwed into the case, however they also suspend the module PCB at a lower height in the case, so getting these parts correct is critical to ensuring that the PCB mounts properly.

However, I was unable to find the part number of this part anywhere within the official GitHub repository; any design documents / mechanical drawings only refer to them using vague language like “UMA FAN PCB STANDOFF” or “SSD PCB WASHER”, with no part number being specified. The schematic of the Dual SSD Reference Design does list what appears to be an outer/inner diameter, however no height value is listed there either, which as mentioned is significant since the washers also suspend the PCB vertically. I would appreciate any pointers which could help me locate the correct part for use with my own design.

Note that I am not talking about the threaded insert for the interposer; I am instead referring to the standoffs/washers which are used to screw the PCB into the expansion bay case itself. The README of the official repository points out that the threaded insert is the only custom part needed (and I was already able to obtain some through the developer program), so I am under the assumption that this standoff/washer is an off-the-shelf part.

Thank you for any help in advance, and kind regards

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2

Very good question. We’re digging into this internally to figure out if this is an off the shelf part or if we need to provide it to developers.

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This is a custom part, and we’re getting a reel so that we can cut strips of them for developers. In the meantime, here is a drawing. You can probably 3D print a standoff that you can glue to the PCB:

image
image512×568 16.2 KB

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STL file, slightly modified for printing:
fw_expansion_bay_standoff_1_long.stl (191.9 KB)

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I see, and thank you for the quick and helpful response! Any rough ETA until this part will be available through the developer program? I’m not in a hurry since I still have to place the order of the final prototype batch (the current batch has other mechanical issues preventing it from being mounted anyway), however depending on how long the sourcing process might take I might have to look into getting some substitute parts printed just like you described.

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Probably more on the order of months than weeks, since we don’t know the lead time on getting extra reels.

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