Hollowing your mesh for the Powder Printer with Meshmixer

If Meshmixer isn’t yet installed on your computer, follow the instructions found here to set it up with preset environments for YSoA 3D printers.

If you’re unable to hollow out a mesh for the powder printer without incurring some damage, or issues with the mesh, one option is to use Meshmixer. Open Meshmixer from the start menu.

If you will be loading a mesh, click on either of the Import buttons; both the one of the left sidebar and the one in the center will work. Select your mesh in the file browser.

The loaded mesh will then appear in a bounding box that represents the print volume of the powder printer. If your object was exported far from the world’s origin the bounding box, model, or both, may be unviewable at first. If this is the case, move the mesh towards the world origin in your modeler and re-export it.

Click Edit in the sidebar, then select the Hollow function.

Set the Offset Distance to be no less than 2mm. Keep in mind that as you change the values in the Hollow function’s interface, the model will update live. If you set options that will take a long time to calculate you may tie up your computer or lose your work in meshmixer. Some calculations, at their extremes, can take several hours to complete.

The Solid Accuracy and Mesh Density values are set according to 8-bit values, which is to say that 256 is equivalent to 100%. A solid accuracy of 256, means that Meshmixer will attempt to provide a mesh accuracy similar to the initial model you importad. To run a “highly” accurate set of calculations, increase the number past 256. To create the interior surface with slightly less accurate results (which will generate much faster), move the slider below 256. Note that the complexity of these calculations do not increase directly. A slight decrease in solid accuracy will result in a much faster and somewhat less accurate set of calculations, whereas a slight increase in solid accuracy will greatly increase the number of calculations performed (and thereby the time taken to perform them) with only a slight increase in accuracy of the resulting mesh.

Mesh Density is set on the same scale, but determines the number of vertices and faces that will be created on the inner surface relative the original, outer surface. A less dense mesh won’t be as permissive of small spaces and narrow volumes, but will calculate much faster.

Holes Per Hollow should be set to 1. You can create multiple holes, but by choosing 1, you will only create holes one at a time as opposed to making multiple holes at once. The Hole Radius should never be less than 10mm. Note that this value will need to be typed in, as the slider only goes up to 3mm, but holes up to 10mm can be made. These holes will all be round cylinders extruded along a vector parallel to the normal of the mesh face that the hole is made on.

The original outer surface will be set to a high transparency, and the inner surface will appear solid. If you double-click on your model, a hole will be formed, centered on your click. A red dot will represent the center of the hole and a green cylinder will represent the eventual walls of your hole, though it will not yet be trimmed to the inner and outer surfaces. Double-click on multiple points on your model to form several holes. If you make a hole by mistake, hit Ctrl+Z to undo only the most recent hole. Click on Remove All Holes to clear your created holes.

When you are happy with the holes and the hollow settings you’ve selected, click on the Accept button.

To export the results of your model click on the Export button. If you want to immediately open the file in 3DPrint, click on the Print button in the bottom left corner.