In this tutorial, you are gonna learn about flow rate calibration and how to use it to increase the quality of your 3D prints.
Flow rate calibration is a crucial aspect of 3D printing that often goes overlooked, yet it can make a world of difference in the quality of your prints. In the context of 3D printing, flow rate refers to the amount of filament that your printer extrudes while printing. It’s essentially the rate at which the filament is fed through the printer’s nozzle. This rate is typically measured in percentage, where 100% is the standard flow rate set by your slicing software.
Each type of filament – whether PLA, ABS, PETG, or any other material – behaves differently when heated and extruded. Variations in filament diameter, composition, and quality mean that the default flow rate settings might not be optimal for every filament. Incorrect flow rate can lead to a host of printing issues such as:
- Under-extrusion: Not enough filament is extruded, resulting in gaps, weak layers, and poor adhesion.
- Over-extrusion: Too much filament is extruded, causing blobs, stringing, and dimensional inaccuracies.
Calibrating the flow rate ensures that your printer extrudes the right amount of filament, leading to better layer adhesion, smoother surfaces, and more accurate dimensions.
Steps
- Download and open OrcaSlicer.
- Click New Project in the main window.
- Select the appropriate profiles for your printer and the filament you want to calibrate on the left-side panel. Take note of the current flow ratio value you’re using. You’ll use that later.
- Click the drop down Calibration menu (on the top bar, next to the undo and re-do buttons).
- Select Flow rate > Pass 1.
- Nine blocks will appear in the plate. Click Slice. Each block has a different flow rate modifier, and you’re able to see the different values of flow rate that will be tested in the preview.
- Export the Gcode and print it.
- When looking at these first results, check the block which presents the smoothest surface. Observe the ones with a higher rate modifier will present over-extrusion, while the lower rate ones will have gaps, i.e. under-extrusion. If you’re in doubt between two blocks, choose the one with the higher modifier, as we’ll adjust it down in the next print.
- Before the second test, you’ll have to change the flow ratio value in the filament profile according to the rate modifier in the block you chose. The new value will follow the equation: NewFlowRatio = OldFlowRatio*(100 + modifier)/100. In our case, our value was 0.98 and the chosen modifier was 5, leading to a new value of 0.98*(100+5)/100 = 1.029. We’ll change this value in the filament profile and save it.
- Next, go to the Calibration > Flow rate menu again and choose Pass 2. Ten blocks will appear in the plate, with modifiers varying from 0 to -9. Slice it and print it.
- Again, check the print results and choose the block with the smoothest surface. This time it’ll be more difficult, so feel free to check them in different lighting, touch them and even scratch them with your nails to reach a decision.
- The final flow ratio value will follow the previous equation. For our test, choosing the -3 modifier will give us 1.029*(100-3)/100 = 0.99813.
Results
That’s it! Achieving the perfect flow rate for your 3D prints can feel like an art form, but with careful calibration, it becomes a science that anyone can master. Taking the time to fine-tune your printer’s flow rate for each filament type not only enhances print quality but also makes your 3D printing projects more predictable and enjoyable. So, the next time you load a new spool of filament, remember these calibration steps. Your patience and precision will pay off in the form of beautifully crafted prints. Keep experimenting, keep learning, and most importantly, keep printing!
