Optical QC: EtherCAT control

User, 18 Oct 2026: use an EtherCAT based system.

- Spindle and conveyor on the StepperOnline A6-EC100L2A1-M17 kit
  (100 W, A6-200EC drive, USD 123.29), spindle through a 1:6 belt in
  cyclic synchronous position, conveyor in cyclic synchronous velocity.
- The A6-EC drive has no divided encoder output, so an RS-422
  incremental encoder on the spindle shaft clocks both line-scans; its
  index goes to the drive touch probe for one angle reference.
- Station controller: fanless N100 mini PC with 2x Intel i226, NixOS
  PREEMPT_RT, EtherCAT master EtherCrab (Rust, MIT/Apache) first, IgH
  (nixpkgs, igc native driver on 6.12 LTS) as fallback; no PLC.
- EtherCAT I/O: EK1100, EL1809, EL2809, EL3102 (warp lasers sampled with
  the spindle position, ~1,000 points a turn at 1 ms).
- Safety stays hardwired (safety relay, contactor; no STO at 100 W).
- Edge PC with the GPU stays off the real-time loop.
- BOM: drives, encoder, controller and I/O lines with sources; total
  USD 16,112 to 32,938 (THB 0.53M to 1.09M). Next step: EtherCAT bench.
- Investor render: cabinet and outfeed labels.

docs/equipment/inline-qc-station/inline-qc-station-bom.csv

@@ -8,9 +8,9 @@ Enclosure,"Clear polycarbonate guard, reject zone",1.4 m2,,30,70,42,98,per m2; e
 Enclosure,"Door hinges, handle, safety door switch",1 lot,,120,350,120,350,estimate
 Conveyor,"PU round belt 6 mm, welded endless",2 x 3.8 m,,15,40,30,80,"each; PU round belt listings (RS, Amazon) plus welding"
 Conveyor,"Round-belt pulleys, shaft, bearings, UHMW slide strips, side guides",1 lot,,250,700,250,700,"pulleys USD 5 to 11 each (ServoCity, REV); rest estimate"
-Conveyor,"Conveyor drive: small gear motor with drive, or servo",1,,250,600,250,600,estimate
+Conveyor,"Conveyor drive: 100 W EtherCAT servo kit (same as the spindle), cyclic synchronous velocity",1,StepperOnline A6-EC100L2A1-M17,123,300,123,300,"USD 123.29 kit, China warehouse (StepperOnline, Oct 2026); high end allows for shipping, duty and a small belt reduction (estimate)"
 Handling,"Guided lift cylinder, 20 mm bore, 75 mm stroke",1,SMC MGPM20-75,330,450,330,450,SMC MGPM20-30 USD 322 (Misumi US) to 390 (Motion); 75 mm stroke a little more
-Handling,Spindle servo kit 100 W with drive; the drive's divided encoder output (A/B/Z) triggers the line-scans; 1:6 timing belt to the spindle,1,StepperOnline A6-RS100L2A1-M17 (A6-200RS pulse/RS485 drive),109,250,109,250,"USD 108.78 kit, China warehouse (StepperOnline, Oct 2026); high end allows for shipping and duty (estimate)"
+Handling,"Spindle servo kit 100 W, EtherCAT (A6-200EC drive), cyclic synchronous position; 1:6 timing belt to the spindle",1,StepperOnline A6-EC100L2A1-M17,123,300,123,300,"USD 123.29 kit, China warehouse (StepperOnline, Oct 2026); high end allows for shipping and duty (estimate)"
 Handling,"Spindle head: bearing housing, timing belt, label pad, pneumatic expanding mandrel",1,machined parts,600,1800,600,1800,estimate
 Handling,"Rodless cylinder 25 mm, 350 mm stroke, with paddle",1,SMC MY1B / CY3B class,400,900,400,900,estimate
 Handling,"Valve terminal, FRL, tubing, fittings",1 lot,,400,1000,400,1000,estimate
@@ -26,10 +26,12 @@ Vision,Strobe and light controllers,2,,300,800,600,1600,estimate
 Sensors,"Laser distance sensor, 50 mm range",2,Micro-Epsilon optoNCDT 1420,520,1600,1040,3200,"list from EUR 470 (Micro-Epsilon); ILD1420-25 about USD 1,600 (Radwell)"
 Sensors,Photoelectric presence sensors and one through-beam,5,,50,150,250,750,each; estimate
 Sensors,"Cylinder position switches (lift up/down, pusher home/out, mandrel open/clamped)",6,SMC D-M9 class,25,60,150,360,each; estimate
+Sensors,"Spindle incremental encoder, RS-422 line driver, 2,500 to 5,000 pulses a turn: A/B clock both line-scans, index to the servo touch probe",1,Omron E6B2-CWZ1X class,60,300,60,300,estimate
 Sensors,"Thermal camera (option, not in the total)",0 (1 optional),Optris Xi 400,2100,3000,0,0,"from EUR 1,950 (Optris); USD 2,995 (moviTHERM)"
-Control,PLC for sequence and safety I/O,1,Mitsubishi FX5U-32MT or Delta class,500,1096,500,1096,"FX5U-32MT/ES USD 1,096 (Mitsubishi US shop); resale from about USD 470"
+Control,"EtherCAT station controller: fanless mini PC, Intel N100 class, 2x Intel i226, NixOS with PREEMPT_RT, open-source EtherCAT master (EtherCrab or IgH)",1,Topton / CWWK N100 2x i226 class,162,470,162,470,"from USD 162 (Alibaba listing) to 279 to 469 at retail (plugpcs.com, Newegg), Oct 2026"
+Control,"EtherCAT I/O: EK1100 coupler, EL1809 16 DI, EL2809 16 DO, EL3102 2 AI (warp lasers), end terminal",1 set,Beckhoff,430,780,430,780,EK1100 USD 131 (industrialsupplygroups); EL1809 EUR 78 net (industry-electronics); EL2809 USD 99 net (TME); EL3102 EUR 111 (automation-base) to USD 290 (plcpartssolution); Oct 2026
 Control,"Edge PC with GPU, 4 GigE PoE ports, NixOS",1,,1500,3200,1500,3200,"qscompute buying guides 2026: USD 1,490 to 3,200"
-Control,"HMI touch panel, 10 inch",1,,400,900,400,900,estimate
-Control,"Safety relay, e-stop, door interlock wiring",1 lot,,300,600,300,600,estimate
+Control,"HMI touch panel, 10 inch, showing the station's browser page",1,,400,900,400,900,estimate
+Control,"Safety relay, e-stop, door interlock wiring, contactor in the drive supply (the 100 W kit has no STO)",1 lot,,300,600,300,600,estimate
 Control,"Cabinet, power supply, breakers, terminals, wiring, stack light",1 lot,,800,2000,800,2000,estimate
-Total,"Hardware per station, thermal camera excluded",,,,,16073,32734,sum of the lines above
+Total,"Hardware per station, thermal camera excluded",,,,,16112,32938,sum of the lines above

docs/equipment/inline-qc-station/render_annotated.py

@@ -27,8 +27,8 @@ ANCHORS = [
     ("lscan_bot", V(778, -31, 547), "Line-scan camera, bottom", "the underside, in the same turn"),
     ("lasers", V(880, -130, 925), "Laser warp sensors", "edge run-out and dish, to 0.1 mm"),
     ("pusher", V(1320, -300, 1020), "Reject pusher", "pushes a failed record down a chute into the bin behind"),
-    ("outfeed", V(1715, -140, 902), "Outfeed", "good records wait for the spindle"),
-    ("cabinet", V(1420, -200, 450), "Control cabinet", "PLC, drives and the NixOS edge PC"),
+    ("outfeed", V(1715, -140, 902), "Outfeed", "good records wait for sleeving"),
+    ("cabinet", V(1420, -200, 450), "Control cabinet", "EtherCAT controller, drives and the NixOS edge PC"),
     ("hmi", V(1770, -404, 1235), "Touch screen", "every verdict with its reason"),
     ("estop", V(1140, -386, 970), "Emergency stop", "and a safety switch on the tunnel door"),
     ("stack", V(1120, 274, 1720), "Stack light", "green: pass, red: reject"),