Flow Control for Pellets: Know Your True Volume

Rotation Volume (Pellet Mode)

Audience: G1 pellet users (open‑material)

Goal: Set a correct and stable Rotation Volume so the printer extrudes the same amount of plastic that Ginger Slicer asks for.

1) What Rotation Volume is (and why it’s different)

• Rotation Volume means how many cubic millimetres of plastic come out with one full turn of the screw.
  
• When Pellet Modded Printer is enabled in Ginger Slicer, the extrusion rate (E) in the G‑code is treated as cubic millimetres of volume. Example: E = 100 means “push one hundred cubic millimetres of plastic”.
  
• With pellets this value depends on the material grade (viscosity, fillers, moisture, etc.). The same screw turn does not give the same volume for every plastic. That’s why Rotation Volume is tuned per material and grade.
  

You don’t need to do any maths. You will simply measure what comes out and adjust the number until the printed line matches what the slicer planned.

2) Before you start

1. Pellet Modded Printer is already ON by default in Ginger Slicer — no action needed.
   
2. Choose a starting material profile close to your pellets (one of the Ginger profiles, or duplicate Generic).
   
3. Flow is already 100% by default. Leave it at 100% while you tune Rotation Volume.
   
4. Decide the first‑layer line width and first‑layer height you want (for example, 3.5 mm width and 1.5 mm height). Check these values in Preview.
   
5. Make sure the three temperature zones are stable. Avoid any melting in the Feeding zone; if you see soft pellets at the throat/hopper, lower that zone a little and/or reduce back‑pressure.
   
6. Dry pellets. Use the default first‑layer speed (about 50–70 mm/s) already set in Ginger Slicer. Prepare a simple test model (a cube) with a single skirt.
   

3) First‑layer method — step by step (no maths)

We make the printed first layer match what you set in the slicer.

What you need

• A caliper (or thickness gauge)
  
• A simple cube model with one skirt
  
• A clean nozzle tip and bed
  

A. Prepare in Ginger Slicer

1. Confirm that Pellet Modded Printer is active (it is enabled by default).
   
2. Choose or duplicate a material profile close to your pellets.
   
3. Set Flow to 100% (and leave this untouched while tuning).
   
4. In First Layer settings, decide your line width and height (for example, width 3.5 mm, height 1.5 mm). Check the Preview to see these values.
   
5. Use the default first‑layer speed (about 50–70 mm/s).
   
6. Start the print of the cube.
   
7. Watch the skirt or the very first lines.
   

C. Set the height correctly (Z offset / nozzle height)

1. While the first line is printing, press Pause on the printer display and measure the height of the line on a straight segment. Then press Resume.
   
2. Compare with the first‑layer height from the slicer.
   
3. If the line is too squashed (very wide, very shiny): raise the nozzle a little using the live Z offset on the printer display.
   
4. If the line is a round rope that barely sticks: lower the nozzle a little with the live Z offset.
   
5. Repeat small moves until the measured height is the same (or very close) to what you set in the slicer. Only continue when the height is correct.
   

D. Measure the line width

1. On a straight segment of the same line, measure the width with the caliper. Avoid corners and overlaps.
   
2. Take three readings along the skirt and use the average.
   

E. Change Rotation Volume based on what you see

Compare your average measured width to the planned width from the slicer:

• If the measured line is wider than planned, the printer is pushing more plastic than expected → increase Rotation Volume by about the same amount.
  
• If the measured line is narrower than planned, the printer is pushing less plastic → decrease Rotation Volume.
  

Quick correction guide (examples):

• Planned 3.5 mm → measured 3.7 mm → increase Rotation Volume by about +5%.
  
• Planned 3.5 mm → measured 3.9 mm → increase by about +10%.
  
• Planned 3.5 mm → measured 4.0 mm → increase by about +15%.
  
• Planned 3.5 mm → measured 3.2 mm → decrease by about −10%.
  
• Planned 3.5 mm → measured 3.0 mm → decrease by about −15%.
  

Where to change it: In Ginger Slicer open your Material → find Rotation Volume (mm³ per screw turn) → edit the number → save the material, re‑slice, and print the first layer again.

F. Validate the result

• After the change, print the first layer again and measure the width.
  
• If the width is within about 5% of the planned value, you’re good to go.
  
• If not, do one more small adjustment to Rotation Volume and re‑check.
  

G. Save your material

• When you are satisfied, save the material profile with a clear name (for example: supplier + polymer + grade). This keeps the correct Rotation Volume ready for next time.
  

4) Flow vs Rotation Volume (don’t mix them)

• Rotation Volume sets the real volume per screw turn for a specific material grade. Tune this first.
  
• Flow is a small finishing adjustment for surfaces or special cases (only a few percent), used after Rotation Volume is right.
  

5) Open‑material reality

• The G1 is open‑material. Different suppliers and grades (even two PLAs) will need their own Rotation Volume.
  
• Start from the closest Ginger profile, then duplicate and save a material profile per grade with its Rotation Volume. That way you can switch pellets without re‑tuning each time.
  

6) Troubleshooting while tuning

• Printed width varies up and down: dry the pellets; slow the first layer; keep screw speed steady; stabilize temperatures.
  
• Melt creeping up the throat or a plug at the hopper: feeding zone likely too hot or back‑pressure too high. Lower the feeding‑zone temperature a little, raise mid/exit slightly, reduce speed, or use a larger nozzle.
  
• You can’t reach the target width: re‑check the first‑layer height (Z‑offset). Make sure Flow is still 100% while tuning. Confirm the previewed width/height match what you’re measuring.
  

7) Quick reference

• Order of operations: height first (Z‑offset) → measure width → adjust Rotation Volume → re‑slice and check again → optional tiny Flow tweak at the very end.
  
• Where to edit: Material profile → Rotation Volume.
  
• With Pellet Modded Printer enabled: the E value in G‑code means cubic millimetres of plastic.
  

8) Frequently asked questions

I measured a thinner line than planned. What should I change?
Lower the Rotation Volume a little, by about the same percentage difference you observed.

Should I ever change the firmware “rotation distance” for pellets?
No. Leave firmware values alone. Use the Rotation Volume inside Ginger Slicer for each material.

When do I touch Flow?
Only after Rotation Volume is correct, and only by a few percent to polish the look.

9) Credits & history

Pellet mode for Orca Slicer was created by Ginger Additive, with help from Vipul Rajan and Giacomo Guaresi. It now ships in our maintained fork, Ginger Slicer, to ensure stability and faster updates.

Why this matters: as far as we know, this was the first production‑ready pellet workflow integrated into a mainstream slicer (2024). Making E represent volume and exposing Rotation Volume (mm³ per screw turn) helps make pellet printing predictable and easy to tune.

Thanks: a big thank‑you to the Orca Slicer maintainers and community for their open‑source work, reviews, and discussions that made this possible.