Parametric 10 Inch Server Rack Mount

Update Sept 6th, 2025: I have finally gotten around to upgrading my version of FreeCAD to 1.0.2 and with it making sure I can still edit spreadsheet parameters, since it appears several people were having issues. I have made separate files with and without the final fillets added. I have been able to change length, width, and depth on both versions without breaking anything (though I do get some errors that don't seem to impact the model updating), but if you're having trouble I'd try the model without fillets and see if that works better.

I have also discovered that anything below ~70 mm for depth breaks the model. Editing the U-cutout sketch manually will fix this if you need to go smaller.

Update Feb 14th, 2025: I goofed and uploaded an older version of the FreeCAD file, which had the faceplate width slightly larger than the 10" rack spec of 254mm (the old file used 260mm). I have just made the correction and reuploaded the file with the corrected faceplate width.

Suggested print parameters. These worked well for PETG with very minimal flex supporting a Lenovo m920q. For switches you could likely dial back the number of solid layers or perimeters:

• 0.2mm layer height
• 4+ bottom layers and 5+ top layers
• 6 perimeters w/ 0.6mm nozzle or 9 perimeters w/ 0.4mm nozzle
• 10+% infill
• I used PETG. PLA may work fine, but I was concerned about creep

I was surprised there wasn't a generic rack mount for all of our various electronics boxes, so I made my own. 

If you can measure the height, width, and depth of your box and it fits in a 1U 10" rack space, you too can make custom rack mounts just by plugging in a couple numbers into a spreadsheet.

If you just want to adjust the model to fit your box you only need to tweak the first three parameters. Here's a brief description of the rest:

• rack_thickness: thickness of the rack aside from the front panel.
• rack_gap: margin added to the device width, height, and depth. I've found 0.5mm to be plenty to provide clearance without feeling loose
• offcenter_distance: shifts the mount off center left/right relative to the 1u plate
• hex_side: length of one side of a hexagon cutout
• hex_gap: distance between edges of hexagon cutouts
• hex_outer_gap: distance between outside of mount and beginning of hex cutouts

NOTE: FreeCAD with spreadsheets is awfully slow to update/save/export, at least on my computer. You may need to wait a minute for the model to recalculate after updating each value. Also I did a bit of stability testing on the CAD model but it's still (very) far from indestructible if you start plugging in extreme numbers. If you find an obvious issue let me know and I'll do what I can to fix it!