Effects of Part Orientation for SLA/DLP/LCD 3D Printing

In the last article, we have discussed about how to improve surface quality in 3D printing by optimizing part orientation. However, effects of part orientation for SLA/DLP/LCD 3D printing are not only for surface quality. Here, you have to take all the below factots into consideration when designing your part orientation in SLA/DLP/LCD 3D printing.

Step 1: Surface Quality

As discussed in the last article, sudden changes of the model structure from a small cross-section to a large cross section area will lead to severe volumetric changes of layers as the volume of 3D resin in each layer highly affects the shrinkage of each cured layer. Uneven quantity of 3D printing material and tumultuous peeling force among layers result in variable shrinkage which is the main cause of misrun and irregularity.

Sudden changes of the model structure not only affects model integrity, but it will also typically result in visible surface lines. Besides, part orientation impacts surface quality due to the process of slicing and reproducing the part in increments in the Z direction.

Step 2: Print Time

Orienting the print correctly will also affect the print time. Generally a lying print will save more time compared to the same upright one when printing. It can be easily understood as you must take much longer to build a four-storied building than a two-storied one with the same story height and build speed. (DLP/LCD reproduces parts by layers.)

This will be even clearer under CHITUBOX slicing preview. As you can see, it takes much shorter to build a lying 30*30*5mm square (23min) than an upright 5*30*30mm one (2h7min).

Step 3: Support Structures

Part orientation plays a crucial role on where support is located for SLA/DLP/LCD 3D Printing. By reorienting a part, the amount of support can be drastically reduced and the cross-sectional area of each layer can be minimized.

SLA/DLP/LCD is very often used for applications where appearance or a smooth surface finish is required. In this case, it’s important to orient your part to avoid adding support structures to the forward-facing areas and areas where the supports are not easily removed.

Step 4: Part Accuracy

Let’s take a cylinder with a hole (10 mm outer diameter, 6 mm inner diameter, 30 mm length) as an example. If we put it standing on the build plate, it will be produced as a series of concentric circles with a relatively smooth outer surface.

While if the same cylinder is reorientated lying on the build plate, it will be produced as a series of rectangles. Besides, the surface of the cylinder that touches the build platform will be flat and the part accuracy will be distorted.

In addtion to the above aspects, part orientation will also affect the part strength, printing success rate and other aspects.