MacBook Wrist Rest for the Sharp Front Edge – Height-Matched Palm Bridge, Held by the Laptop's Feet

A pair of low palm bridges that stand on the desk in front of an open MacBook Air (13 / 15-inch, M2 and later) or MacBook Pro (14 / 16-inch, 2021 and later). Your wrist rests on a flat, rounded land 2-3 mm higher than the laptop's raised front edge, so it bridges over the sharp aluminium corner instead of resting on it, with a 2 mm air gap to the laptop. A thin 1.2 mm tab under each half carries the laptop's own front rubber foot, so the bridge moves with the laptop instead of drifting away - and nothing is stuck to or rests on the laptop. One reading of the printed step gauge picks the matching pair.

Validation status (please read): designed and checked in CAD (heights, a section check with a rigid wrist shape, foot positions, calculated anchoring) and in the slicer (no supports). It has not been physically printed or tested - please print the gauge first and report. Images are renders of the CAD model and drawings from it, not photographs; the laptop in the images is a generic stand-in.

Features

• Height matched to your laptop from one reading of the printed step gauge (7.0-17.0 mm in 0.4 mm steps, the crown number engraved under every band of steps): the land sits about 2-3 mm above the raised edge.

• Calculated section check: a rigid wrist (R25-R40) resting on the bridge and the deck clears the sharp corner by at least 0.4 mm, a rigid forearm line by at least 1.4 mm (with the edge 0.2 mm higher than read: at least 0.3 / 1.2 mm). Soft tissue can still touch under heavy pressure.

• Carried by the laptop's own front feet: each half moves with the laptop when you slide it (calculated from the foot load and an assumed friction).

• Nothing on the laptop: no adhesive, no clip, nothing on the palm rest; a 2 mm air gap set with the included setup key.

• A calm, soft form: vertical face to the laptop, a flat land, one convex curve down to a rounded toe, rounded ends. The only marking is the engraved foot outline on the tab.

• Two flat parts per laptop, no supports, no hardware, no assembly; the gauge and setup key are printed once.

Which laptops?

MacBook Air 13-inch and 15-inch (M2, M3, M4, M5) and MacBook Pro 14-inch and 16-inch (2021 M1 Pro / Max through M5). Not the 2020 MacBook Air M1 (wedge shape). Desk use only - it does not help on a lap.

Dimensions

• Half length: S family 143 mm (Air 13 / Pro 14), L family 161 mm (Air 15 / Pro 16). The outer end lines up with the laptop's side; an 18-34 mm centre gap leaves the lid notch free.

• Crown height 11-21 mm (picked by the gauge), reaching 33-55 mm in front of the laptop; the 1.2 mm tab reaches 46 mm under it.

• The laptop's front rises by the tab, about 1.2-1.4 mm (a tilt of about 0.4°).

• Both halves of a pair share one plate, from about 143 x 167 mm (S crown 11) up to about 161 x 210 mm (L crown 21). On a small bed (e.g. 180 x 180 mm) print the halves one at a time.

Which files?

• edgebridge_1_print_first_gauge_and_shim.3mf - the step gauge + setup key (print first, about 1 h 33 min / 20 g on a generic profile).

• edgebridge_S_gauge_…_crownNN.3mf (Air 13 / Pro 14) and edgebridge_L_gauge_…_crownNN.3mf (Air 15 / Pro 16) - one ready-to-print PrusaSlicer project per gauge band, both halves on one plate. The file name tells you the gauge steps it covers, e.g. edgebridge_S_gauge_11p8-12p6_crown16 = steps 11.8-12.6 mm. These 3MF files also open in other 3MF slicers.

• gauge.stl / setup_key.stl and model.py - the parametric CadQuery source: family, measured deck height, target height above the edge, gap, tab.

Print settings

• Matte PLA or PETG (PETG if the desk gets warm in the sun - the files carry a PLA profile, switch it). Any colour; dark graphite reads as a calm desk object.

• 0.4 mm nozzle, 0.2 mm layers, no supports. Halves flat on the bed as they stand on the desk (crown up); only the top land is ironed. Gauge and setup key flat.

• Pairs take about 3 h 40 min (S crown 11, 46 g) to 7 h 59 min (L crown 21, 108 g) - PrusaSlicer 2.9.6 estimates on a generic PLA profile.

Measure, print, set up

1. Print the gauge file first.

2. Open the laptop on a bare desk. Lay the gauge on the desk along the laptop's front face, steps against the face and the 7 end at the laptop's left corner, so the steps you read stay clear of the centre lid notch (it is lower and would give a wrong reading). Find the step whose top is level with the front edge (feel it with a fingernail). The number engraved under that step is your crown; between two steps take the higher one. Example: a 14-inch Pro level with the 12.6 step (number 16) -> edgebridge_S_gauge_11p8-12p6_crown16.

3. Print that pair.

4. Lift the laptop's front about 1 cm, slide both tabs under it with the outer ends lined up with the laptop's sides, and lower the laptop. Stand the setup key's 2 mm grip in the slot between bridge and laptop near each end and nudge the bridge back against it. Each front foot then sits inside the engraved outline.

5. Using only one half? Slide the setup key's 1.2 mm card under the other front foot, about 25 mm in from the side, so the laptop does not rock.

Type as usual. To move the laptop, slide it - the halves follow. If a half was pushed back, reset the gap with the setup key.

Limitations

• Not physically printed or tested. Fit, clearance and anchoring are calculations on the CAD.

• A comfort accessory, not a medical device - no claim about any condition.

• The fit relies on your own gauge reading, taken away from the centre lid notch.

• The halves are not fixed: they move with the laptop when it is slid, but can be pushed away on purpose; the 2 mm gap is kept by friction only.

• The thumbs over the 18-34 mm centre gap are not supported (the gap keeps the lid notch free).

MacBook, MacBook Air and MacBook Pro are trademarks of Apple Inc. This design is not affiliated with or endorsed by Apple. Images are renders of the CAD model and drawings from it, not photographs; the laptop in the images is a generic stand-in.