Skip to content
Ch 09Checkpoint

Checkpoint 09

Checkpoint · Chapter 09 — Electronics bay

What you should have now — The two DIN rails, the 24 V PSU, the SSR, the mains WAGO mount and the power inlet panel, plus the XY endstop pod that goes on the gantry. Nothing here is size-dependent. Most of what this chapter adds sits under the deck, out of this camera's view: use the layout v3 overlay at Step 09.6 for the bay. The CAD also has no Leviathan and no LDO nozzle probe, so the front rail is emptier here than yours will be; it does model a separate Pi bracket, which Step 09.8 tells you to skip on this kit.
  • Two DIN rails run left-to-right, each bolted with one M5×10 BHCS into each bed extrusion, all four plastic end caps fitted.
  • DC loop VHB'd at 09.36 as one closed loop, middle run 1.5 mm or more off the Leviathan and the PSU; AC conduit VHB'd against the WAGO bus, behind the SSR and over the round deck hole; notch clear; every lid off and bagged. LDO layout: five PVC ducts, the opening clear.
  • Meanwell LRS-200-24 selector set to 115 V, on the rear rail via its two printed brackets, front-right corner 2 mm or more clear of the right T's rear fillet and left end 3 mm or more from the SSR run's open end — and no support bracket fitted.
  • Omron SSR on its metal bracket, latched to the rear rail left of the PSU, LOAD (1/2) and INPUT (3+/4−) identified and reachable.
  • Every Leviathan voltage-selection jumper removed and bagged.
  • Leviathan on the front rail with the Pi 4B mounted on it, heatsink fitted, SD card in, and the 3/4 HAT power adapter seated.
  • USB adapter on the front rail with the partial cover and the supplied grounding cable attached to its exposed point; frame end left loose for Ch 10.
  • IEC inlet module (one part, not two) in power_inlet_IECGS_1mm, panel bolted to the rear extrusion hard against the rear-left Z-motor mount; three WAGO 221-415 clamps in the mains WAGO mount to its right.
  • Nozzle probe assembled — collar home, PCB on two M2×10, shaft free — and mounted on M3×25 SHCS above the deck on the right bed extrusion's inner slot, pin 1.5 mm behind the plate's straight rear edge; its lead not yet through the deck. If the 5 mm shaft is out (un-notched, 09.29), it is bagged and labelled probe shaft — refit before 13.24.
  • XY endstop PCB on the pod, pod on the gantry, full X and Y travel with no fouling.
  • Bed WAGO breakout built and mounted above the deck on the left bed extrusion, under the plate's rear half; the plate's three leads reach it with slack and the plate still lifts off from above.
  • Nothing wired. Nothing plugged in. Duct lids off, skirts and bottom panel off. Multimeter on the bench.
Revali passing a gate
You built a fully fitted electronics bay with nothing wired yet. 8 gummy worms.

Common mistakes

  • Fitting the p.169 support bracket "because it's in the manual". LDO explicitly skips it; the two printed brackets are the mount. Bolting an unneeded L-bracket to the frame just puts a screw where a cable wants to go.
  • Leaving the Leviathan's voltage jumpers in. The one mistake in this chapter that destroys hardware. They come out before the board is installed, not before it is wired.
  • Setting the PSU selector after the bay is full. Once the PSU is on the rail behind a wire duct the switch is nearly invisible. Set it at 09.14, before it goes on the rail.
  • Fitting the V1 USB adapter cover. It hides the grounding point that Rev D+ exists to expose, and the ESD path silently ends up broken.
  • Closing the bay, or plugging the cord in "just to see the PSU light". Both belong after Checkpoint #1 in Ch 10 (survey §5.2 W8).
  • Over-driving M2 self-tapping screws into ASA. Two turns too far strips the boss and the DIN clip or the Z endstop PCB never sits solid again.

Next

Ch 10 — Wiring: above-deck, below-deck, mains and Checkpoint #1 (LDO wiring guide, in its own order, plus manual p.194–195 for drag-chain slack). Nothing in this bay gets energised until that checkpoint passes.

Source: LDO wiring guide § General Placement · survey §7.5

pause Good stopping point · ~45 min since the last one

both conduits stuck down with their lids off, bay fully populated, tagged and checked against the v3 overlay and LDO's layout, printer still on its head, mains-safety hardware staged in one labelled bag, meter beside it. Do not start Ch 10 in a leftover ten minutes: mains work is a fresh session with a clear head, and it ends at LDO's Checkpoint #1.

← PreviousStep 09.36 — Stick down both conduits, then check the bay

Next →Ch 10 — before you start