8.3 Printing and iterating

AI workstation · 11 Oct 2026

Every v3 part prints without supports, in black PLA Basic on the textured PEI plate. Times and weights come from A1 slices at 0.20 mm, 2 walls and 15% infill, each including the start sequence of about 6 minutes.

Part	Orientation	Size on the A1	Time	PLA
Carrier	Flat, front face down	162 × 168 × 51 mm	2 h 21 min	95 g
Shell	Back down on the textured plate	162 × 155 × 47 mm	2 h 43 min	88 g
Fin E1, E2, E3	Flat, profile on the bed, 14 mm tall (E1 20 mm)	up to 161 × 88 mm	50 min to 1 h 10 min	35 to 49 g
Foot E1, E2, E3	Flat, 30 mm tall	up to 240 × 180 mm	2 h 59 min to 4 h 1 min	138 to 189 g

Coupon first

The dock is the one new fit in v3, so it gets a gauge before the full parts, as in 3:

Coupon	Print	Size	Time	PLA
Collar	Flat, as the carrier: the collar cut out with a little of the plate	36 × 38 × 50 mm	45 min	15 g
Tongue	Flat, as a fin: the top of E2's fin with its tongue, shoulder and pin hole	56 × 51 × 14 mm	24 min	11 g

On one plate the pair takes about an hour, because the start sequence runs once. Slide the tongue into the collar and check three things: it slides with no play, the shoulder seats flat on the collar, and an M3 pin passes through both. Then print the full parts.

Sealing steel in a print

Each foot has a closed cavity 6.2 mm deep, from Z = 1.6 to 7.8 mm. In Bambu Studio I add a pause at 8.0 mm, before the first layer over the cavity. At the pause the steel goes in: a 6 mm plate cut to the cavity, or steel shot levelled off. The print resumes, and the ceiling prints 0.2 mm above the steel, which carries it like a bridge.

The slicer's command line cannot add the pause, so the sliced files in the repo are summaries only. The real G-code comes from Bambu Studio.

Print the beam as a beam

The fin is the only beam in the stand, and the bending figures assume a solid section. At 2 walls and 15% infill its edges are only 0.84 mm of wall. The fins print with at least 6 walls and 40% gyroid infill.

Bridges and openings

The collar's pocket prints as a tunnel in the flat carrier, and its roof bridges only 14.4 mm.
In the shell, every opening runs to the rim or is a slot whose long axis is vertical in the print. No edge bridges more than 3 mm.
Heat-set inserts sit only in the carrier's pillar tops, axis vertical. Fins and feet use through bolts with nyloc nuts, so no insert sits in a side-loaded layer.

What changed after the first build

The checks and the slicer found problems. Each fix is in the build script:

Change	Before	After
Steel ballast in each foot	Push to tip 3.5 to 3.9 N at the weakest edge	5.3 to 6.6 N, up to 9.1 N
A shoulder on the fin's neck	The neck was the tongue's size, so the screen's weight hung on the M3 pin	The neck bears on the collar's face; the pin only locks
The tenon down to the slot's floor	E1's and E3's tenons stopped 0.2 mm short, so the weight hung on the M4 bolts	The tenon bears on the floor; the bolts only locate
Shell wall	2.5 mm: 103 g, 3 h 20 min	1.8 mm: 90 g, 2 h 44 min (88 g, 2 h 43 min after the side exit)
Back bevel	3 mm	5 mm, with the inside chamfered to match

The shell and the bevel each taught something about the process:

Thin walls break the 35% rule. Every mass so far took 35% of a part's volume as printed solid, from a slice of the v1 band. That read the 2.5 mm shell at 46 g. The slice said 103 g, because a wall that thin is all perimeters and prints solid. The check now takes every printed mass from the slices.
The slicer is a check. A 5 mm bevel on a plain cavity cut right through the 1.8 mm wall, so the back came away from the sides. The slicer refused it ("empty layer between 1.8 and 3.8", exit 156). I missed that at first, because a failed slice left the old slice.json in place. Now the build fails unless the carrier and shell are one valid solid each.
A fix can break its neighbours. Chamfering the cavity to match the bevel then cut 37.6 mm³ into two pillars and the collar. The pillars moved and the collar notch grew. The overlap check caught it.

The two bearing fixes are the same lesson as 4.3 in a new form. A part that fits can still carry its load through the wrong thing. Fasteners should locate and lock; faces should bear.

Repeatable checks

At the end, the model was closed, reopened from the saved file, and checked again. The new checks.json was identical. That proves the saved file holds the design, not some state left in the running FreeCAD session.

Modelling problems

OCCT would not offset a single spline edge, so E1's bowed fin failed to build. Its centreline is now a fine polyline.
2D face booleans left split faces. They now go through thin solids.
The dock pin ran 0.4 mm into the shell's bottom wall. It moved 5 mm down.
Two shell pillars sat in the cable path and cut 9 mm³ into the shell's corner. They moved into the bay's corners.
The first bending check gave 18 MPa on E1, about 100 times the real figure. Each section's cutting plane also passed lengthwise through the fin's neck, so it measured the wrong section. The check now clips the fin to a sphere round each centreline point before cutting. When a number jumps by two orders of magnitude, suspect the method before the design.

Hardware per device

4 × M4 × 10 countersunk (VESA), 2 × ISO 7379 shoulder screws for the PC, 3 × M3 heat-set inserts and 3 × M3 × 8 countersunk for the shell, 1 × M3 × 30 and nyloc nut for the dock pin, 2 × M4 × 40 and nyloc nuts for the plinth.

Still open

Which stand.
Weigh the monitor; every balance figure assumes 0.8 kg.
Print the dock coupon. It is ready but not printed.
Measure the PC's temperature under load inside the shell.
Cable routing and desk pads, which became 8.4.