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Under-desk clamp-on homelab rack

Four mini PCs, a switch and an external drive hung under a desk in a single plywood box — cut from one sheet, clamped on with no holes drilled in the desktop. Two bays face opposite directions, so you see clean hardware from the chair and every cable is hidden behind it.

33" wide 10" deep 10" high ¾" birch ply 8 pieces 23 holes no drilling into the desk

Interactive models

Both run in the browser. Drag to orbit, scroll to zoom, click any piece to isolate it.

The numbers

Clear space is the air inside each bay, wood excluded. Both bays are identical.

Clear width
31-5/8"each bay
Clear depth
9-5/16"each bay
Clear height
3-15/16"each bay
Usable volume
1,157 in³per bay
Empty weight
22 lb38 lb loaded
Load per clamp
9.5 lb4 clamps at 8-1/4" pitch

Cut list

One 4×8 sheet of ¾" PureBond birch (0.703" actual). All cuts are straight rectangles — no joinery of any kind. R1–R3 are the three rip cuts.

#PartLengthWidthQtyRip Holes
1Top panel33"10"1R1
2Clamp doubler31-9/16"2-3/4"1R3
3Front wall31-9/16"3-15/16"1R3
4Middle shelf31-9/16"10"1R25 x 2" grommet holes, one per device
5Side panel (left)10"8-9/16"2R2
6Rear wall31-9/16"3-15/16"1R36 x 2" cable pass-throughs, equally spaced
7Bottom panel33"10"1R112 x 1-1/2" vent holes, 2 rows of 6
Why these two numbers depend on your actual plywood
  • Inner panel length = 33" − 2 × thickness = 31-9/16" — rounded down on purpose; a piece that drops in between the sides must never be long.
  • Side panel height = 2 × bay + thickness = 8-9/16"
  • Both assume 0.703". Measure your sheet with calipers and recompute if it differs — everything else is independent of thickness.

Hole schedule

23 holes across three panels, two hole saws (1½" and 2"). Positions are measured from the left end of that piece.

PanelCountAcross the lengthPosition Purpose
Middle shelf5 × 2"3-11/16" · 9-15/16" · 16-3/16" · 22-7/16" · 28-5/16"7-1/2" from frontcables up into the hidden cable bay
Bottom panel12 × 1½"3-1/4" · 8-1/2" · 13-3/4" · 19" · 24-1/4" · 29-1/2"2-1/2" and 5"cool air in, two under every device
Rear wall6 × 2"2-5/8" · 7-7/8" · 13-3/16" · 18-7/16" · 23-11/16" · 28-15/16"2" upcables straight back to the wall

Downloads

Drawings are print-ready on US Letter. Sheet 9 is written as a cut request you can hand to the panel-saw associate.

Individual panel STLs
Parametric source — change one number, regenerate everything

How it works

Two opposite-facing U bays

The front wall closes the upper bay and the rear wall closes the lower one. Because they sit on opposite faces, the cross-section forms a closed loop — that is what stops a 33"-wide box with no back panel and no front panel from racking into a parallelogram.

Cables never cross the view

Each machine's cables go straight up through the grommet directly behind it, into the bay you cannot see, and out the open rear to the switch and power. Six more holes in the rear wall take anything heading straight to the wall.

Clamped, not drilled

Four heavy-duty C-clamps grip the rear edge of the desk, out of knee space and hidden against the wall. A doubler under the top panel gives the jaws 1.41" of plywood to bite so they cannot crush the top ply.

Airflow

Every device sits over a pair of floor vents, has an open front, vents up through its own grommet and has a pass-through in the wall behind it. There is no sealed pocket anywhere in the box.

Build at your own risk. This hangs roughly 38 lb over your legs on friction clamps. Check your desktop can take the load, use clamps rated well above 9.5 lb each, pad both jaws, and re-check them after the first week and every few months after. Dimensions are published as-is with no warranty — verify against your own material and equipment before cutting.