Step 12.28 — Verify the 0.9° A/B motor setting¶
Step 28 of 37 · Chapter 12 — Software: Pi OS image, Klipper/Moonraker/Mainsail, firmware, printer.cfg
(no image — see text)
Parts: none.
Do: Confirm, do not change, that [stepper_x] and [stepper_y] both read:
full_steps_per_rotation:400 #set to 200 for 1.8 degree stepper
Check
X/Y = 400, extruder = 200, and none of the four [stepper_z*] sections has a full_steps_per_rotation line; they inherit the 200 default.
What you're looking at
full_steps_per_rotation is how many full steps the motor takes per revolution. A/B motors are 0.9° units, 400 steps; the Z and extruder motors are 1.8° units at 200. Nothing warns you if this is wrong: every X and Y dimension comes out doubled or halved.
and that [extruder] reads full_steps_per_rotation: 200.
Why: the Rev D+ A/B motors are LDO-42STH48-2004MAH(VRN), 0.9° — 400 full steps per revolution. The Z motors (LDO-42STH48-2004AC(VRN)) and the extruder motor (LDO-36STH20-1004AHG(VRN)) are 1.8°. LDO already sets this correctly in the -sbv2 config; the value is on this checklist only because it is the one thing that will silently halve or double every X/Y dimension if someone "fixes" it. src
Good stopping point · ~15 min since the last one
every 350 mm dimension is set (X/Y/Z limits, QGL corners, resonance point, G32 end position) and the 0.9° A/B motor setting verified. SAVE & RESTART completes cleanly.
Source: leviathan-printer-rev-d-sbv2.cfg · LDO Rev D 350 BOM