FR4-R7: from FR4-R6 replace ONLY the lid. All five other panel shapes, posts, screws, VESA washers and supports are retained. Guide tubes are retired. Remove the lid for VESA mounting; the exact 100 x 100 mm base pattern remains. Read FABRICATION-NOTES.txt and PORT-DESIGN.txt before machining. SiDi128 FR4-R7 — FR4 panels and metal spacer construction BASE AND LID: 133 x 133 mm. Both use twelve matching CLOSED tab slots. SIDES: 130.6 x 130.6 mm envelope. Both horizontal panels extend 1.2 mm past those faces, leaving 1.0 mm of FR4 outside their slots to capture the tabs. MAXIMUM: 133 x 133 x 33.6 mm, unchanged from R6. Projecting connectors and external VESA spacers are excluded. Only the lid changes from FR4-R6; the five other panel shapes are retained. Six 2.0 mm FR4 panels and metal spacer columns. No printed structural brackets or heat-set inserts are required. FOUR PCB MOUNTING COLUMNS — use the existing MH5-MH8 holes 4 x M2.5 MALE/FEMALE metal hex standoffs, 8 mm BODY + 6 mm male STUD, 5 mm across flats (5.774 mm maximum across corners). 4 x M2.5 FEMALE/FEMALE metal hex standoffs, 20 mm BODY, 5 mm across flats. 8 x M2.5 x 5 COUNTERSUNK screws, 90-degree head, head diameter 4.6–4.8 mm: four through the bottom, four through the lid. Length INCLUDES the head. The lower post's male stud points UP through the PCB into the upper post. The PCB is clamped between the two post shoulders. The lower and upper posts stay tightened when the lid screws are removed; the board does not come loose. Do not substitute a female/female lower post: its stud is what holds the PCB. Do not use a single spacer that leaves the PCB floating without clamping. Nominal vertical stack, measured from bottom exterior: 0.0-2.0 mm: bottom FR4 panel 2.0-10.0 mm: lower 8 mm metal post 10.0-11.6 mm: mainboard 11.6-31.6 mm: upper 20 mm metal post 31.6-33.6 mm: lid FR4 panel The 6 mm male stud passes through 1.6 mm PCB and engages the upper post 4.4 mm. Each M2.5 x 5 countersunk screw engages its post nominally 3.0 mm. Specify at least 3.2 mm usable lower female thread, 4.6 mm upper bottom thread, and 3.2 mm upper top thread; check purchased hardware against actual parts. Use a 5 mm spanner on the flats. Hold posts when tightening or removing screws. The metal shoulders sit on the board's existing grounded mounting pads. The four positions are asymmetric: MH5 is inset from the rear. Do not relocate it to a cosmetic corner. The CAD includes hex bodies, studs and screw shafts; helical threads and driver recesses are not represented. Dimensions/examples (no purchasing performed): Lower, 8 mm body + 6 mm stud, 5 mm AF: https://www.vital-parts.co.uk/threaded-hex-standoffs-male-female/11379-hmf-m25-8-s5-npb Upper, Harwin R25-1002002, 20 mm body, 5 mm AF, through threaded: https://www.harwin.com/products/R25-1002002 VESA / REMOVE LID FOR SCREW ACCESS 3 x metal support spacers: OD 7 / ID 4.6 / length 8 mm, under the PCB's M4 mounts. 3 x M4 washers: OD 8 / ID 4.5 / thickness 0.8 mm, placed above the PCB mounts. 3 x external VESA spacers sized for the monitor surface, nominal 5 mm or more. 3 x M4 screws: head <=7 mm diameter x 4 mm high. Choose under-head length for the monitor's specified engagement and measured spacer stack. With 5 mm external spacers, nominal stack is 17.4 mm plus monitor engagement. Three axes form an exact 100 x 100 mm grid. Existing mainboard hole centres are within 0.134 mm of those axes. The fourth corner is unavailable on the board. Remove the four lid screws and lift the lid off before mounting or unmounting. M4 heads, washers and a 6 mm driver envelope clear the full board with the lid removed. Use a 3 mm Allen key; refit the lid after tightening the M4 screws. The three former lid access holes and all guide tubes have been removed. ASSEMBLY — closed slots require the horizontal panels to fit LAST 1. Assemble each 8 mm lower male/female post and 20 mm upper female/female post through the mainboard, with the short body below and long body above. Tighten the post shoulders gently against the PCB. Leave the base and lid detached; do not secure the PCB to the base before fitting the sides. 2. Slide the four sides horizontally over their connectors at the final PCB height. Hold the corners together with removable tape while assembling. Keep the PCB and posts supported; this tape is only an assembly aid. 3. Position the three M4 washers above the PCB and three support spacers below. Small removable retaining dots can keep them aligned during handling. Fit the lid vertically over all twelve upper tabs and the four upper posts. Secure it with four M2.5 x 5 countersunk screws. 4. Support the assembly on its lid on a soft surface. Fit the base onto all twelve lower tabs and the four short posts, then install the remaining four M2.5 x 5 countersunk screws. Remove the temporary corner tape. 5. To mount to the monitor, remove the lid. Hold the external spacers between the base and monitor and lower the M4 screws from above through the washers, PCB holes and lower supports. Tighten with a 3 mm Allen key and refit the lid. Do not force a side vertically over the projecting connector shells. The side panels must slide horizontally while the lid and base are detached/clear. SERVICE Remove the lid and detach from the monitor. Undo the four bottom screws, and lower the base by at least 3 mm to clear the lower tabs. Support the PCB/post assembly during this operation. Side panels then pull straight outward over the ports at their original height; no lifting over the connectors is needed. With the base seated, its CLOSED slots deliberately prevent outward movement. The PCB remains clamped between its metal posts when case screws are removed. To remove the board, remove the panels and unscrew its four upper posts. FABRICATION / FIT SAMPLE Base and lid need exterior 90-degree countersinks: primary hole 2.9 mm, major diameter 4.8 mm, depth 0.95 mm. The four sides need no countersinks. Gerbers/Excellon alone cannot describe countersink depth; see the included CSV, drawing and instructions. The six flat STLs are optional plastic FIT SAMPLES of the FR4 panels, not parts required by the final FR4 construction. Check panel thickness and tab fit, actual connectors/cables, SD handling, standoff thread depths, stiffness and VESA load before production. The narrow base/lid slot retaining webs require supplier review. No physical load or thermal testing is claimed. The model does not simulate the SD eject latch. CONSTRUCTION REFERENCE The original SiDi kit photograph shows six tabbed acrylic panels, short M/F and long F/F metal posts, and top/bottom screws. R7 uses that arrangement with FR4 panels and the current SiDi128 board's actual mounting locations. https://manuferhi.com/c/sidi-sidi128 https://manuferhi.com/p/sidi SCREW HEAD RETENTION The visible 4.8 mm circle is a countersink, not a through hole. The shaft hole is 2.9 mm. A 4.6–4.8 mm head overlaps that throat by 0.85–0.95 mm per side and seats on the 90-degree conical face. A 4.8 mm head sits flush; a 4.6 mm head is recessed 0.10 mm. Nominal post engagement is 3.0–3.1 mm. There is 1.05 mm of FR4 below the 0.95 mm countersink in a 2.0 mm panel. See preview/screw-head-fit.svg and validation/screw-head-fit.json; all eight actual fixing holes were checked. Panel geometry and drill sizes are unchanged.