Electronics — Wire harness

Wire harness

Reference

24V power distribution from the PSU, plus everything connected to basically board v1.3.

Wire IDs match the schedule tables. Open items are in section 7.

These electronics pages are working notes right now, not finished documentation. The harness is actively being specced, so parts of this change week to week and some of it contradicts what a machine already built looks like. Anything still undecided is written down as an open item in section 7 rather than smoothed over. Started from what Spencer had on July 12th 2026; treat it as the current thinking, not the final state.

1 Power supply

Model: MEAN WELL LRS-350-24
Output: 24V, 14.6A, 350.4W, single output
Enclosure: Custom 3D-printed box, fused AC input
DC outputs: 3 × female DC jack, each a 4 in 18 AWG pigtail with 2 × spade/fork terminals (M3.5, 8 mm wide max) onto the PSU output
Loads: basically board v1.3, the USB hub, and the Orange Pi buck converter. One jack each, no spare
Not on this bus: The cooling fans. They run off the Orange Pi or basically board v1.3 instead, so their voltage follows whichever pins are free (5V is likely sufficient). They are still needed: the Pi and the board end up in a box with no airflow but the fan. See open items

2 Component layout

Top-down physical component layout on the machine, with the PSU, Pi, basically board, USB hub, Pico, chute stepper and ribbon run called out — Physical placement on the machine (top-down): PSU, Orange Pi, basically board v1.3, USB hub, Pico, the chute stepper and its limit switch, and the ribbon run.

3 Interconnect diagram

PSU distributes 24V to basically board v1.3 (through a JST-VH inlet) and the two other direct loads (USB hub, Orange Pi buck). Cooling fans are not on this bus, they run off the Pi or the board. basically board v1.3 then drives the LED drops (L1-L3), the limit switch, the steppers, and the first servo adapter board over a 16-pin IDC ribbon. Wire IDs match the schedule below.

3.1 Stepper polarity

Source of truth is the basically board v1.3 pinout. Cable S plugs into the motor's own 6-position JST-PH socket, so the four board positions 1·2·3·4 land on motor positions 1·4·3·6 and motor positions 2 and 5 stay empty. The nets line up, the positions do not. Mark polarity on each of the 4 channel steppers, and check the coils with a multimeter first.

Full basically board v1.3 pinout (J23-J40), connector-to-connector mapping, and connector reference: stepper connectors.

4 Wire schedule

4.1 PSU assembly (enclosure)

The PSU box is an assembly: the MEAN WELL LRS-350-24, a fused mains inlet switch, and 6 DC output jacks, in a 3D-printed enclosure. These are the wires inside that box. Enclosure CAD: Onshape.

Segment	From	To	Cond.	Length	Gauge
Mains inlet	Fused inlet switch (3Dman, 10A fuse)	PSU AC input (L / N / earth)	3	-	18 AWG
DC output jacks (×3)	PSU 24V output, 2× spade/fork terminal (M3.5, 8 mm max)	Female DC jack	2	4 in	18 AWG

4.2 Loads on the PSU (24V)

A male DC barrel plug on each wire mates one of the PSU output jacks (J1-J3).

ID	Load	From	To	Cond.	Length	Gauge
W1	basically board v1.3	PSU J1, male DC	JST-VH female (board 24V in)	2	36 in too long	TBD
W2	Waveshare 4-port USB hub, 24V	PSU J2, male DC	Male DC (hub)	2	12 in	TBD
W3	Orange Pi 5	PSU J3, male DC	24V-5V USB-C buck	2	6 in	TBD

Three outputs, three loads, no spare. The cooling fans are deliberately not on this bus.

4.3 LEDs (from basically board v1.3)

Each LED drop is two segments: a 2x1 dupont feed from the board to a female DC jack (the unplug point), then a 6 in male-DC pigtail into the module. The strip end uses a solderless clamp-on connector rather than soldering to pads.

ID	Segment	From	To	Cond.	Length
L1	COB board feed	2x1 dupont (board)	Female DC jack	2	36 in
L1p	COB board pigtail	Male DC jack	COB board	2	6 in
L2	COB board feed	2x1 dupont (board)	Female DC jack	2	36 in
L2p	COB board pigtail	Male DC jack	COB board	2	6 in
L3	LED strip feed	2x1 dupont (board)	Female DC jack	2	36 in
L3p	LED strip pigtail	Male DC jack	LED strip (6000K)	2	6 in

LED strip for the classification channel is 6000K. Length: 2× revolutions around the classification channel inner tube = 108.400 mm × 2, so roughly 220 mm.

4.4 Sensors and steppers (from basically board v1.3)

ID	Segment	From	To	Cond.	Length
LIM	Limit switch (Omron V-155-1C25)	basically board v1.3, 1x3 dupont (position 3 empty)	#187 quick-connect, push-on	2	24 in
S1-4	Stepper, channels 1-4 (×4)	basically board v1.3, JST-PH 4-pin (PHR-4)	Stepper, JST-PH 6-pin (PHR-6), positions 1·4·3·6	4	1 m
CH	Chute stepper	basically board v1.3, JST-PH 4-pin (PHR-4)	Chute stepper, flying leads, needs prep	4	40 in guess

Done, and here is why: the stepper cables are JST-PH 4-pin at the board, not 4x1 dupont. Dupont contacts do not take side load. The wires leave at an angle, that depresses the spring contact, the connection goes loose, resistance goes up and it heats. Two of these have already burned up on real machines. JST-PH takes the side load without damage.

4.5 Servo adapter (ribbon)

ID	Segment	From	To	Cond.	Length
RIB	Ribbon cable	basically board v1.3, 16-pin IDC (FC)	First servo adapter board, 16-pin IDC (FC)	16	1 m

uxcell 16-pin IDC flat ribbon cable, gray, with FC connectors at both ends

5 Parts

MEAN WELL LRS-350-24, 350.4W 24V 14.6A single output · link
3Dman fused mains inlet switch, 15A 250V rocker + 10A fuse, 3-pin, 18 AWG · link
DC 12V/24V to 5V USB-C buck converter, 5A 25W, powers Orange Pi 5 · link
Cooling fan, 40mm. Not on the 24V bus: it runs off the Orange Pi or the board, so the voltage follows whichever pin header it ends up on. 5V is likely sufficient.
uxcell 16-pin IDC flat ribbon cable, FC/FC, 2.54 mm, 1 m, gray · link
Waveshare 4-port USB hub, 24V model (USB 3.2 version, not the 5V industrial one, which cannot take 24V in)
Orange Pi 5
USB cables, Pi to hub and hub to Pico: 3 ft or shorter is plenty, but they must be data cables. A lot of short USB cables are power-only.

6 Connector and terminal types

Fused IEC inlet switch, 3-pin (L / N / earth): PSU mains inlet
Fork / screw terminal: PSU 24V output to the DC jacks
DC barrel jack, female: PSU outputs, LED unplug junctions
DC barrel jack, male: load pigtails, LED pigtails
JST-VH female (VHR-2): basically board v1.3 24V input (W1)
2x1 dupont (2.54 mm): LED drops (L1-L3)
1x3 dupont (2.54 mm), 2 positions populated: limit switch board end, keyed so it cannot go on backwards
Quick-connect receptacle, #187 (4.75 × 0.5 mm tab), fully insulated: limit switch end. The switch is an Omron V-155-1C25, SPDT, so it has three tabs and the harness uses two
JST-PH 4-pin (PHR-4): steppers at the board, J23, J27, J31, J35, J39
JST-PH 6-pin (PHR-6): the NEMA 17 motor socket, cable S motor end
16-pin IDC (FC), 2.54 mm: ribbon to first servo adapter board

7 Open items

How the fans are powered. They are wanted: the Pi and the board end up in a box with no airflow but the fan. They are just not on the 24V bus, so they run off the Pi or the board and the voltage follows the available pins. 5V is likely sufficient (Spencer, 2026-08-09).
Lengths. W1 is 36 in and longer than necessary. Pick a final length and cut.
Board 24V input polarity. The connector is JST-VH (VHR-2) per Jon's drawing; confirm which pin is +24V against the silkscreen.
Missing LED wire(s). Re-count the LED drops against the actual LEDs.
Gauge per segment. Current draw per load is needed to spec gauge.
SKU reduction. Once gauges are known, standardize on as few gauges and connector types as possible.

The order spec page fills these in with guesses (marked as guesses) for ordering purposes. Nothing there is confirmed.