What does under extrusion mean for 3D printing?
If all the layers of your 3D print are not printed correctly, it is likely due to under extrusion. Under extrusion is a complex problem that can lead to missing layers or layers that are not fully printed, leading to gaps in the model. Unfortunately, we cannot pinpoint a single culprit. Under-extrusion can have several causes, which makes it difficult to determine the actual problem. It usually has to do with using the correct extrusion width.
Unfeasible extrusion width
When we talk about extrusion width, we mean the width of the printing layer that the printer extrudes. How wide or narrow this layer can be depends on the nozzle size used. The printer software has default values for how wide a layer can be for a given nozzle size (100% is the minimum extrusion width for each nozzle and 120% is the maximum). If you enter a layer value that is too thin or if you use the wrong nozzle, the layer cannot be converted to a printing layer and therefore will not print. This results in missing layers in your model. Check which extrusion width is to be used and that you are using the correct nozzle for this width. If you cannot obtain the desired width with any nozzle, the model will need to be adjusted in the CAD software. You can also manually adjust the extrusion values in the printer software, but the options are limited because it must be technically feasible.
When under extrusion occurs, you would expect the solution to lie in pushing more filament through the nozzle and thus adjusting the pressure. This is possible, but only to a certain extend and with the right temperature. When the pressure is too high, the chance of a clogged nozzle is very big. Which in turn causes under extrusion to occur again, because the filament isn’t printed correctly anymore.
Under extrusion is an adhesion issue, that could be caused by an unfeasible extrusion width. The dddrop printers have changeable nozzles, which allows for a big range of extrusion widths that can be printed. Furthermore, dddrop delivers the right basic settings for each material which helps to achieve the best result possible.