ErgoPoint42

Use the Plus plain version, with no tall headers. The original non-Plus XIAO lacks the required accessible pins. Solder both underside battery joints.

Two 30-packs supply 60 switches: 42 fitted and 18 spare. The default product page may select the linear version; use the exact tactile variant link. Physical fit of retail suffix -03 still needs a sample check against the family drawing.

Each order must include the sensor, driver PCB and working OEM sensor-to-driver interconnect. Listing explicitly includes sensor, driver and red cap; interconnect completeness needs confirmation. Keep the OEM link. Five carrier wires attach to castellated driver pads 1 through 5, not the FFC pin numbering.

• Sprintek manufacturer store; price and stock not reconfirmed in this ordering pass ↗

Ships with JST-PH. P1 uses JST-SH, so convert the leads using the connector items below and verify polarity: J3 pin 1 BAT+, pin 2 GND. Firmware selects 50 mA charge. Battery switch must be ON to charge; USB still powers the controller with it OFF. Do not assume the TrackPoint works down to the pack cutoff.

Right half only. Select the display right frame and matching right firmware. The supplied tall headers are not used. Omit this item for the plain right frame.

• Manufacturer specifications and vendors ↗

21 diodes per half, 42 total. Buy 50 cut-tape parts, leaving 8 spare. Cathode stripe faces ROW. Installed component height must be no more than 1.35 mm; do not select another package.

U2, one per half. Carrier ties pin 5 QOD to pin 6 OUT. Keep the exact DCK package.

Exact native footprint. A different slide switch needs a footprint and enclosure check. OFF disconnects battery power and charging; it does not disconnect USB power.

R1 and R2 on each half. Ten at the quantity tier cost less than four at the single-piece price; 6 spare.

R3 on each half. Suggested prototype order leaves 8 spare.

C1 on each half. Maximum listed body height 0.90 mm; keep installed height at or below 1.0 mm. Eight spare.

C2 and C3 on each half. Maximum listed body height 0.90 mm; keep installed height at or below 1.0 mm. Six spare.

J3, one per half. Mouth points outward. Pin 1 BAT+, pin 2 GND.

One housing per battery. Contacts are not included; use the precrimped leads below.

Cut each double-ended lead at its middle to make four roughly 25 mm contact tails total. These supply all four SH contacts. Mark polarity because the wires are black, splice to the original pack leads, insulate and verify the finished connector. Check routing length before cutting.

Counted here for native BOM coverage only. Buying loose contacts instead requires correct tooling; the linked base listing has a full-reel minimum of 23,000, unsuitable for this prototype.

Five short carrier-to-driver wires per half, plus five for the optional right display. Keep the original sensor-to-driver links. Cut to the measured route, leave service slack, and label both ends if using one color. Do not run wires across the XIAO antenna.

• NCE manufacturer wire specification ↗

Retain a compact lead by replacing the original PH connector with the SH housing and insulated precrimped tails above. A plug-to-plug PH-to-SH adapter is an alternative only after checking its extra bulk in the case; the model does not reserve a mated PH pair. Components are already counted.

Six per half. Supplier lists 7 mm length, 90° head, 2.88 mm head diameter and 0.96 mm head height. This is a dimensional candidate for the model's 6.9 mm screw, not a physical fit approval. Confirm head seating, nut engagement and tip clearance on a sample. Exact item uses Phillips No. 0; the 8 mm Accu fallback uses PZ0 and requires qualified shortening.

• 8 mm Accu SPK-M1.6-8-A2 fallback; requires qualified shortening/deburring, price/stock unconfirmed ↗

Six per half. Three 4-packs give exactly 12 nuts. Model pockets are 3.3 mm across flats; verify actual nuts fit without splitting the print.

Six per half. 3M specifies solid polyurethane with R-30 natural-rubber adhesive, nominal 0.8 mm total thickness excluding the release liner, tolerance ±0.13 mm. Cut twelve Ø5 mm circles. Seats are Ø5.2 mm and 0.2 mm deep, giving nominal 0.6 mm exposed height. Do not add another adhesive layer. Check actual thickness, roundness, grip and adhesion to the finished PA12 sample. This is a verified material route, not an off-the-shelf or physically qualified finished foot.

• Bulk SJ5832-4.5-5 rollstock listing; 37-roll minimum and not kept in stock when checked, unsuitable as the default prototype buy ↗
• 3M SJ5832 manufacturer product page ↗
• 3M technical data: construction, total thickness, tolerance and measurement without liner ↗

One fitted board of this hand. Left and right are distinct designs, not two copies of one board. Keep board thickness at 1.0 mm. These are prototype fabrication previews; physical component fit remains to be checked.

• ergopoint42_p1_left.kicad_pcb ↗
• Supplier ordering and quotation guide ↗

One fitted board of this hand. Left and right are distinct designs, not two copies of one board. Keep board thickness at 1.0 mm. These are prototype fabrication previews; physical component fit remains to be checked.

• ergopoint42_p1_right.kicad_pcb ↗
• Supplier ordering and quotation guide ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• base_left.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• base_right.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• frame_left.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• frame_right.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• frame_right_plain.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• battery_tray_left.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• battery_tray_right.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• pointing_extension_left.stl ↗

PA12 is the preferred structural prototype material. Print local FDM fit samples before that expense. Choose exactly one right upper shell. Validate the actual switch, pegs, nut pockets and battery fit before final finishing.

• pointing_extension_right.stl ↗

Print in flexible TPU. Qualify stem retention, hardness, grip and keycap clearance on a physical sample. Use the supplied P1 nub mesh.

• pointing_nub_left.stl ↗
• Supplier TPU process and material ↗

Print in flexible TPU. Qualify stem retention, hardness, grip and keycap clearance on a physical sample. Use the supplied P1 nub mesh.

• pointing_nub_right.stl ↗
• Supplier TPU process and material ↗

Original geometry means the unmodified source mesh, not an off-the-shelf set. Preserve the exact orientation and profile recipe. Use MX-size files, not Choc-size files. Test stem fit first.

• MX_Stem_MX_Size_Normal_Tilted.stl ↗
• KLP-Lame creator and CC BY-SA 4.0 license ↗

Original geometry means the unmodified source mesh, not an off-the-shelf set. Preserve the exact orientation and profile recipe. Use MX-size files, not Choc-size files. Test stem fit first.

• MX_Stem_MX_Size_Saddle.stl ↗
• KLP-Lame creator and CC BY-SA 4.0 license ↗

Original geometry means the unmodified source mesh, not an off-the-shelf set. Preserve the exact orientation and profile recipe. Use MX-size files, not Choc-size files. Test stem fit first.

• MX_Stem_MX_Size_Thumb.stl ↗
• KLP-Lame creator and CC BY-SA 4.0 license ↗

Print one each for R, T, F, G, U, Y, J and H. These replace eight source caps; do not add them on top of 42 standard caps. Total cap recipe: 16 Normal Tilted + 6 Saddle + 12 Thumb + 8 modified = 42.

• L04_R_trackpoint_clearance.stl ↗
• L05_T_trackpoint_clearance.stl ↗
• L09_F_trackpoint_clearance.stl ↗
• L10_G_trackpoint_clearance.stl ↗
• R04_U_trackpoint_clearance.stl ↗
• R05_Y_trackpoint_clearance.stl ↗
• R09_J_trackpoint_clearance.stl ↗
• R10_H_trackpoint_clearance.stl ↗
• KLP-Lame original creator ↗

Use small pieces to insulate exposed lead joints and likely contact points. Keep the printed battery trays; tape does not replace their rigid insulation. Whole-roll cost is not per-pair material consumption.

Candidate for removable non-load-bearing driver or cable retention. Check adhesion to the actual print material and keep the USB antenna area clear. The preferred SJ5832 foot material already includes its own adhesive; do not add this tape to it.

• 3M product specification ↗

For through-hole and SMD joints. Use existing compatible electronics solder if available. Whole-spool price is a workshop purchase, not material consumed by one pair.

For the small PCB components and castellated module joints. Buy only if not already in the workshop.

One for the right host connection and one for independent left charging. Existing cables can be reused. Choose a host-end connector that matches your computer or charger; USB-C-to-C alternate is linked. No wired cable connects the two keyboard halves.

• USB-C to USB-C data cable, Adafruit 4199, $9.95 each when checked ↗

Assemble SC70/0603 components, solder XIAO castellations and prepare fine leads. Choose a stripper that handles 32 AWG.

Check battery polarity and continuity, rail voltages and actual switch, connector, screw and printed dimensions.

Match the final screw. The 8 mm Accu fallback uses PZ0 and requires qualified shortening/deburring. A punch is only needed if making SJ5832 feet locally.

First power checks and PS/2 clock/data validation for the unbuilt prototype. Not components installed in the keyboard.