Extrusion Multiplier

prusaprinters

TL;DRA faster and handy way to calculate the extrusion multiplier. Collectiontools, 3D printingMotivationWhile working with several layer heights between 0.10 and 0.48 mm combined with extrusion widths between 0.2 and 1.6 mm we observed that sometimes the given extrusion width and that what comes out of the printer differs.You see ugly horizontal stripes on you prints. Let's get started What is the Extrusion Multiplier?The Extrusion Multiplier is a correction value you can set in your slicer configuration, to correct the amount of plastic running through  the nozzle for a given setup. Default is just 1.0 and often seen values, are between 0.9 and 1.1.Think about it as a factor to decrease (lower than 1) or increase (higher than 1) the amount of plastic getting extruded. Total flow rate = Flow multiplier in firmware (M221) x Extrusion multiplierWe will now call the extrusion multiplier EM to safe typing. Do i need it?It is always a good idea to have a well calibrated printer, so yes you need it and it is easy and stress free to handle that. The only tool you need is your digital caliper and maybe a calculator to add and divide 8 numbers. What will it do for me?It helps you to avoid ugly looking uneven top layers and ugly uneven sides / walls / spheres of your prints. Your prints get better with a well calibrated flow rate for your setting and filament. The goal is that if the model has 20mm you get it printed with 20 mm and not with 19.5 or 20.3 mm. How to use this toolThe goal is to figure out the best EM for a given:printernozzle sizenozzle temperaturelayer heightprint speedextrusion wideand filamentThis list tells us already that the EM is heavily connected to many other settings, this is why sometimes a great printing filament shows less quality while changing only a single parameter like the print speed or temperature. While the EM in prusaslicer is a filament setting and safed as a filament config you will found situations where you need to change that based on other settings.This tool needs to be printed in VASE mode, so only the “external perimeter” settings are valid for changes to figure out the best value for the multiplier.You found that setting in:Print Settings → Advanced → External Perimeter  The EM setting himself is found in:Filament Settings → Filament → Extrusion multiplier(in this screenshot the EM is set to 1) Let's do it!print the octagonmeasure the 8 sidesadd the valuesdivide by 8divide the external perimeter wide from your slicer by this valueThe result is your extrusion multiplier.  ExampleWith a 0.4 mm nozzle we chose a external perimeter width of 0.42 mm and a layer height of 0.16 mm, this comes out:0,400,390,390,400,400,400,400,40That sums up to: 3,18Divided by 8: 0,3975 so we have an under extrusion!So we get 0.42 / 0.3975 = 1,056We have to increase the extrusion multiplier by 1.05 to 1,06 to ensure that the chosen perimeter wide got printed dimension accurate.   Side effect the single bottom layer octagon is printed with horizontal infill, so we get a little first layer test at the same time. Lazy JoeThe Lazy Joe model prints a prism, so Lazy Joe has only to add 3 numbers than 8. That reduces the quality of the result because it did not use any stepper combination and direction, but already this is better than the Old School way with 4 numbers. Old SchoolThe cube which gives you 4 sites, but not a single one who uses more than one stepper at the same time, on a bedslinger.  Attribution© yahbluez Can I sell copies of this?Yes! Yahbluez shared this project under the GNU GPL v3.0 license. This license allows selling copies, but you must provide proper attribution and use the GPL 3.0 license, as detailed in the GPL v3.0 license itself. You have not the right to use any other licence than GNU GPL 3.0. DonationIf you like to donate you can buy me a coffee Filament usedThe extrusion multiplier is a filament setting, it belongs to a filament. You will see that different filaments need different extrusion multipliers to print perfect.