The extrusion multiplier or “Flow”, as it is referred to in Ultimaker’s Cura, is an important setting that can have a significant impact on the quality of a 3D print. Adjusting this value will determine how quickly the material is extruded from your printer and can be an effective way to address challenges such as poor layer adhesion or stringing effects. Fortunately, Ultimaker’s Cura software takes the guesswork out of getting the Flow setting right by automatically calculating the optimum rate for a given print speed or filament diameter.
It is important to get the right flow rate when 3D printing, and thankfully, this is relatively easy to do. The most common range happens to be between 90% and 110%, however, it can go lower or higher depending on your printer model and which filament material you are using. Be vigilant with making these tweaks – they could be the difference between successful parts and failures.
However, before you start tuning your 3D printer for maximum performance, it’s important to ensure that it is calibrated correctly. Taking some time to properly calibrate your printer can save you hours of frustration and lead to superior results. If you’re looking to optimize your printer’s performance, our 3D printer calibration guide provides clear steps and advice before you go tampering with flow rate settings.
Here’s where to find the flow settings in Cura if you do believe the flow rate is the problem you need to resolve:
- Switch to the “Custom” settings view while Cura is open.
- “Configure setting visibility” can be chosen by right-clicking.
- Click “Close” after selecting “Check All” (or changing your settings visibility to “Expert”).
- You can now find “Flow,” which has a number of sub-settings, and “Initial Layer Flow” under the “Material” settings.
With an understanding of what adjustments can be made, it’s time to dive into how we can adjust those settings to fix five common issues with 3D printing. The article is focused on just one function, the extrusion multiplier in Cura, but if you’re using another slicer know that similar settings exist for you to experiment with. Keep in mind that these issue-fixing tweaks may not solve every single problem you experience.
Dealing with Under-Extrusion
Under-extrusion is an extremely common printing issue, with insufficient flow rate often being the culprit. If you’re currently dealing with under-extrusion, it might be helpful to attempt to increase the flow rate setting by 5% at a time. Increasing the flow rate can easily counteract the majority of print issues caused by under-extrusion, marking a significant difference in the end results.
A few other factors could be causing your under-extrusion issues – things such as a too-low print temperature, a print speed that is too fast, or even a clogged nozzle. It’s worth trying out some of these other solutions first before increasing your flow rate past 115%. Remember, if changing the flow rate doesn’t get you any improvement in your prints’ appearance, go back and try something else.
High values can cause difficulty in the nozzle of a 3D printer, leading to clogged and jammed material. This can be an issue for machine operators, who must work diligently to dislodge or even replace stubborn nozzles.
Solving Over-Extrusion Issues
If you are experiencing over-extrusion, the opposite issue, then the best option to try first is to lower your printer’s flow rate in 5% increments. This simple adjustment may go a long way towards improving your overall print quality. However, if this change doesn’t have the desired effect on your prints, you might need to try more drastic measures, such as lowering the print temperature or adjusting the filament diameter input in Cura.
Improving Bridging in Your 3D Prints
No one likes a droopy bridge! Fortunately, setting your 3D printer’s flow rate can help stabilize bridges during the printing process. By adjusting Cura’s flow setting, you can adjust the material’s flow rate to an optimal level.
For example, if your filament is being extruded unevenly or at an excessive rate, you can lower the printer’s flow rate in 5% increments until the bridges look more stable and structurally sound. Keep an eye out for any signs of under-extrusion after each adjustment – if that shows up, bring the rate back up again and explore other bridging solutions instead.
Fixing Layer Delamination in 3D Printing
Layer delamination can be frustrating for 3D printing enthusiasts. Thankfully, calibrating the flow rate setting in Cura is an easy fix that often solves the problem.
Try increasing your flow rate in 5% increments and inspecting the results each time until you find a balance between too little and too much filament being extruded. If you increase it too drastically, there’s a risk of over-extrusion or a nozzle clog emerging as problems on their own.
If it still doesn’t work to fix layer separation, take advantage of our other delamination tips and tricks to get your prints back on track quickly and easily.
Improving Bed Adhesion in 3D Printing
Warp Prints that are popping off the plate or not staying in place can be immensely frustrating. However, improving bed adhesion by increasing the flow in 5% increments can sometimes be enough to make all the difference for a successful print job.
By adjusting the flow so that more plastic is being extruded, the first layer should form a firmer bond with the print surface, making sure that your piece sticks where it needs to and remains stable throughout printing.
Be wary of over-extruding though; if too much filament comes out at once, you might end up clogging your nozzle and causing even greater problems along the way! If increasing the flow doesn’t do enough for you, there are other simple solutions that can be employed to fix warping.
I am Bheema Shankar. I have worked on SLS, CJP, DLP, SLA and FDM technologies at Think3D. Currently working as Process and application engineer at VEER-O-METALS PRIVATE LIMITED. I am always fascinated by the process of creating things layer by layer. This fascination led me to pursue a career in 3D printing technology. I am passionate about how 3D works and enjoy exploring new ways to improve the 3D printing process.