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extruder

Christophe Barlieb edited this page May 3, 2026 · 1 revision

StoneFlower BIG paste extruder

The CCL-ALTAR-01 cell uses the 2.5 L "BIG" ram version of the StoneFlower paste extruder — fixed in space, with the robot moving the build plate underneath the nozzle. This page documents what the plugin assumes about the extruder, and the firmware-side knobs that interact with it.

📷 Side-on photo of the StoneFlower BIG extruder mounted in the cell, showing the ram body, auger section, and nozzle.

Specs at a glance

Parameter Value
Ram volume 2.5 L
Ram driver NEMA 23 stepper
Outlet 1" NPT
Default nozzle 2.5 mm (also stock: 1.5, 2.0, 3.0, 4.0)
Microsteps per revolution 62.5 (M92 E62.5)
StoneFlower kit version Ceramic 3DP KIT v3

The microsteps value is computed from the kit geometry: Ne = D · p / (r · df) with D=80, p=2.5, r=50, df=2.5 → 62.5. See the StoneFlower v3 manual for the derivation.

Front-panel controls

The StoneFlower controller has two pots and an SPD signal input the plugin drives indirectly through the post-processor:

Control Range Effect
Auger / ram ratio pot 0.25, 0.5, 1, 2, 4 Multiplies auger turns per ram turn
Microstepping pot (A6) hardware-specific Sets stepper resolution
Speed pot (A7) hardware-specific Sets baseline speed
SPD signal 0–1023 Plugin-driven extrusion rate (S-value in G-code)

Lab convention: ratio pot stays at 1. The calibration data on this wiki (Calibration) was measured at ratio 1. Other positions are valid but uncharacterized — flag any change in the lab study log.

📷 Close-up of the StoneFlower front panel showing both pots labeled and the ratio pot indicator at "1".

Firmware caveat

The StoneFlower v4 firmware (control_v4_SPI_HighPower.ino, March 2020) is publicly documented and treats the STP input as an enable gate — the actual extrusion rate is set by the front-panel pots, not by pulse counting. The CCL unit does NOT run that firmware — a flash dump showed something different, not yet reverse-engineered. If you're tuning extrusion behavior, treat the SPD→flow relationship as empirical, not theoretical, and rely on the calibration curve measured on this specific unit.

In the plugin

  • Settings → Robot → Spindle Speed maps to the S value in generated G-code, which the post-processor emits as the SPD command at the start of each curve.
  • S1 is the convention for extruder off (idle / true zero flow), per the dead-zone in the calibration curve. See G-code conventions.
  • The plugin does not write to M92 — that's a one-time KUKA-side firmware setup.

See also: Calibration for the empirical SPD→RPM curve and the workflow to recalibrate after firmware or hardware changes.

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