I’ve been printing with FDM printers for a while now, but only recently started printing with resin. In FDM printing orientation of the part is important, but with resin it’s a big deal. It got me thinking, maybe orientation is more important to FDM printing than I realized. Here are a few things to consider.

The first thing to consider is the overhang angle of your model. This is the angle between the horizontal plane and the surface of your model. If the overhang angle is too steep, the printer will have trouble depositing material on thin air, and you will need to add support structures to prevent sagging or collapsing. Support structures can be useful, but they also have some drawbacks: they use more material, increase printing time, and leave marks on the surface of your model that need to be removed.

The second thing to consider is the layer direction of your model. This is the direction in which the printer lays down each layer of material. The layer direction affects the strength and appearance of your model. Generally speaking, 3D printed parts are stronger along the layer direction than across it, because there is less bonding between layers than within them. This means that you should orient your model in such a way that the layer direction aligns with the main stress direction of your part. For example, if you are printing a hook, you should orient it vertically so that the layers are parallel to the force applied by the weight hanging from it.

The third thing to consider is the surface quality of your model. This is how smooth and detailed your model looks after printing. The surface quality depends on several factors, such as the nozzle size, layer height, print speed, and infill percentage. However, it also depends on the orientation of your model on the build plate. Generally speaking, 3D printed parts have better surface quality on the top and bottom faces than on the sides, because these faces are printed flat on the build plate or in mid-air, without any interference from support structures or adjacent layers.

Of course, these three factors are not independent from each other, and sometimes you will have to compromise between them. For example, if you want to print a sphere, you will have to choose between having a smooth top and bottom face with lots of support structures on the sides, or having a smooth side face with a rough top and bottom face. There is no one-size-fits-all solution for every model, and you will have to experiment with different orientations to find the best one for your specific case.