Ch 03Checkpoint

Checkpoint 03

Checkpoint · Chapter 03 — Build plate

What you should have now — The bed stack - MIC6 plate, heater, magnet sheet and flex sheet - sitting on the bed support extrusions. CAD bed is the 250 machine's 10 in MIC6 plate. Yours is the 350 plate; it covers proportionally more of the frame.

• Protective film removed; top face clean, magnet applied with no bubbles or wrinkles.
• All four bolt holes trimmed clear through the magnet; a 2.5 mm hex key reaches each bolt head.
• Heater pad flat and centred, pad screws present and untouched — inspected, not re-applied.
• Thermal fuse flat against the plate, screw tight, in-line with a heater lead — inspected, not re-fitted.
• M4×6 BHCS present on the plate as the PE point (washer: verify on bench); nothing wired to it.
• Four M3 roll-in T-nuts in the bed extrusion top slots; four M4 thumb nuts standing as spacers.
• Four M3×20 SHCS fitted (not M3×16); one tightened, three deliberately loose.
• Front edge of the plate 38 mm behind the front edge of the frame, both corners.
• Equal gap under all four corners; no rock; plate clear of every vertical extrusion and Z rail.
• Straightedge check done before the magnet went on — no gap you could slide paper under.
• Three bed leads loose above the deck with slack, none through it, unterminated, nothing pinched or tied.
• Flex plate test-fitted, removed, and the bed covered for the rest of the build.

You built the heated bed, floating level on four spacers. 4 gummy worms.

Common mistakes

• Applying the magnet over untrimmed bolt holes and only noticing at p.59. The fix is a peel-and-replace magnet or drilling through it — both bad. Trim at 03.10.
• Using the M3×16 the manual calls for. It engages barely any thread through a 10 mm plate plus spacer, and strips the T-nut on first tighten. M3×20.
• Tightening all four bolts because three loose bolts feel wrong. The plate tacos on the first fast heat-up to 110 °C and never comes flat again.
• Trying to "fix" the pre-applied heater or fuse. Peeling a bonded AC heatpad to re-seat it wrecks it. Inspect and ask in #ldo_motors if something looks wrong.
• Wiring the bed here, or feeding its leads through the deck. The plate's leads end at the bed WAGO breakout above the deck (Ch 09) and terminate in Ch 10. Landing or threading them now means undoing them.
• Building on the bare magnet, or leaving the surface exposed. The magnet sheet is not a print surface, and everything you drop for the next six chapters lands on it.

Next

Ch 04 — A/B drives and idlers (manual p.62–81): the two gantry drive units and the front idlers, built on the bench with the bed covered.

← PreviousStep 03.20 — Fit the flex plate, then cover the bed

Next →Ch 04 — before you start