Extruder driver and 55V step-up
Status v0 — drafted from a single customer case, pending human review.
When the extruder / feeding motor stops or skips, the cause is usually mechanical (something stuck in the extruder) — but in at least one case it was electrical: the stepper driver was not delivering current because the step-up (boost) converter that feeds it had failed.
Background
Section titled “Background”The main extruder stepper is driven at a boosted voltage of ~55V (higher than the 24V bus) to give the screw enough torque. A small step-up converter produces this 55V and feeds the extruder stepper driver.
What the chats show
Section titled “What the chats show”- Symptom reported: “the feeding motor seems to skip every once in a while” at high flow (~250 mm³), then later the motor stopped entirely.
- Ginger’s triage: “it is nearly impossible that it’s the motor” → “it can be the driver not delivering the current”, and “when the motor stops, usually it’s something stuck in the extruder.”
- Customer’s finding with a multimeter: “the step-up is not outputting 55V and I saw it spark a little — I think this is the problem.” → a failed step-up converter starves the driver, so the motor gets no current.
Diagnosis order
Section titled “Diagnosis order”- Rule out mechanical first — with the printer off, check for material/debris jammed in the screw/extruder; a stalled screw is the most common reason the motor “stops”. See Extruder motor skipping and Nozzle and barrel clog.
- Check flow isn’t simply too high — sustained very high flow can make the motor lose steps; reduce flow / add SmoothFlow, and verify temperatures so the melt isn’t too stiff.
- Electrical: measure the 55V step-up output with a multimeter. If it does not read ~55V (or shows signs of arcing/sparking/scorching), the step-up converter has failed and must be replaced — contact Ginger Additive support.
- Driver — if the step-up is healthy but the motor still gets no current, the stepper driver may not be delivering current.