3D printing is as much an art as it is a science. For successful prints, learn the best ways to optimize each part's orientation. Watch this episode of our tutorial series to understand the full power of orientation control in PreForm.
There are a few ways that you can change your model's orientation in the X, Y, and Z axes; see the suggestions in sections below for the best recommended orientations. The easiest way to rotate a print is to click-and-drag on the spherical manipulator that is overlaid on the model. Rotate any model more precisely in one of the three main axes by dragging one of the circular rings on the manipulator or by typing specific angles into the boxes in the Orientation toolbar. The Z axis rotation can be adjusted at any time - from the Orientation toolbar or using the Z axis rotation ring - without affecting the supports; supports must be re-generated if the X and/or Y angles are adjusted.
Use Command-Z (OS X) or Ctrl-Z (Windows) to undo rotations, as well as other model operations.
If you hover the mouse over the X, Y, or Z rotation box in the orient tool, and move the mouse's scroll wheel up and down, the model will rotate smoothly around the corresponding axis.
The X, Y, and Z rotation angles reset to 0 degrees after applying a rotation. This is because PreForm's orientation tools are relative, not absolute; any rotate change is applied relative to the model's current orientation, not its originating one. To see an example of this behavior, load a model and create a duplicate of it. Select the first copy of your model and apply a 90-degree X rotation, followed by a 90-degree Z rotation. Select the second copy and apply the same rotations in the opposite order: 90-degree Z rotation, then 90-degree X rotation. The result is different.
Vary Print Locations
Extend the life of your resin tank by placing your models in different locations on the build platform each time you print. This prolongs the life of the tank and improves print quality by distributing the amount of laser exposure throughout. Use the manipulator’s translate feature or the Layout toolbar to adjust a model’s position.
“Select Base…” is an orientation tool that allows you to select a face on your model to point down at the build platform. Click “Select Base…” and then click on a specific point on your part. PreForm will then rotate your part into position.
Once you click “Select Base…” your cursor will appear as an orange arrow when you hover over a model.
The part is rotated so that the clicked area faces the build platform.
This is a quick way to orient parts when you have a definite “front” to your model. Selecting the underside as the base can help minimize the amount of post-print finishing you have to do, as the support marks will not appear on the cosmetic surface if it faces away from the build platform.
Tall Supports on Wiper Side
If printing a larger part at an angle, it is good practice to position the taller supports on the wiper side. In PreForm's default view, the wiper side is the right side of the build platform and is labeled “WIPER SIDE”.
The PreForm view represents an inverted perspective of the printed model. Pay attention to the front, hinge, and wiper labels in the layout view when orienting a model.
Print Flat Surfaces at an Angle
Flat surfaces with support structures print much more successfully at an angle of at least 10–20º. You will notice that if you use the automatic orientation in PreForm by highlighting your part and clicking “Orient Selected” it will usually position your piece at an angle. After each layer, the printer performs a “peel” process, which literally peels the printed layer off the PDMS surface of the resin tank. The forces involved can distort the extremely thin layer of a flat surface mounted on support structures. If a planar surface is oriented at an angle to the build platform, there is only a little overhang for each new layer. Furthermore, many thin-walled parts present significantly less area in any slice when printed at an angle.
Orient to Support Overhangs
Parts print one layer at a time. Features that would print as part of a layer without being attached to the base or another section of the model are known as overhangs. Without support structures, such a feature would lose itself in the resin! PreForm Software automatically generates supports to fix this issue. By default, PreForm will also generate internal supports that build from one part of the model to another. You can disable this feature by unchecking “Internal supports” in the Supports menu.
Orient to Support Minima
A minimum point—plural: minima—refers to the lowest local point in any area of a model’s geometry relative to the build platform. Unsupported minima may break off the part during printing and lead to structural defects, warping, or print failures, all of which can contaminate resin, damage the resin tank, or cause resin spills.
Minima are highlighted in red and will fail without additional support.
To resolve unsupported minima on models using the Orientation tool, rotate the highlighted areas away from the build platform.
Learn more about identifying minima in “Chapter 6: Local Minima and Islands” from the video tutorial "Supporting Your Model in PreForm".
Orient to Prevent Suction Cups
“Cups” refer to hollow volumes or cavities in a model. Hollow volumes and concave geometries require more careful attention to the print orientation. When the opening of a cup faces the resin tank, the cup traps air and resin as the build platform lowers the opening of the cup against the bottom of the resin tank. The resulting suction can cause separation between printed layers, structural defects, warping, and print failures, all of which can contaminate resin, damage the resin tank, or cause resin spills.
PreForm automatically highlights in orange any cups that may reduce the printability of a model.
Use the Orientation tool to rotate cups so that the opening of the cavity either faces the build platform or is placed at an angle. Regenerate supports after orienting the model. Orienting cups at an angle or to face the build platform prevents a vacuum from forming between the part and the bottom of the resin tank during printing.
Learn more about identifying and orienting cups in “Chapter 4: Orienting Cupped Areas” from the video tutorial "Orienting Your Model for Printing".
For models that contain internal hollows or are enclosed volumes (for example, a hollow sphere), use CAD software to either fill in the hollow or add drainage holes to minimize suction effects during printing and to avoid trapping resin inside the part.
Save your Work
After all that work orienting your model, you may want to save the layout, or “job”. PreForm Software will create a .FORM file with all of your settings, making it convenient to reload or share the file exactly as you printed it. Do this by selecting “Save” or “Save as…” from the File menu.