ZBrush 3D Printing Tutorial
ZBrush is a digital sculpting tool by Pixologic. Compared to more traditional CAD modelling software, ZBrush is very different and for new users it can be a hell to get started. This tutorial–made during my internship at 3D Hubs–shows how to 3D print your model that was created in ZBrush.
Divide a sculpture–made in ZBrush–into different elements that allows to produce it on a desktop 3D printer.
Firstly, make sure the floor grids are on and visible.
Let’s make sure the grid size means anything and you could say one block is 1 square millimeter for instance. Go to Draw > Put Grid Size to 100 and Tiles to 10. Now you could see if an object is 4 blocks wide, it is actually an object of 4 mm.
To measure your model you can use the Transpose tool or the Move tool. Go to Brushes > Transpose [Shortcut: B, T, R] or select Move (upper menu next to Draw). Click and drag the part you would like to measure (make sure you click on the model). On the upper left corner you will see the units! Hold shift after clicking if you want to measure exactly the vertical distance of the model. The units are either in mm or inches.
If you think the object is a tad too small and it could be a bit bigger, you could of course scale it up so it fits your whole print bed size. Go to Scale (next to the Move button) > Click and drag on the item > Use the red circle to scale the object.
Go to SubTool > Duplicate. I always suggest you to do this, so you can always go back and have your original file to make some adjustments to. Duplicate it twice so you will have one original model, and two models which in the end will be the separated parts.
Hold CTRL (or CMD on Mac) to go in masking model and use the draw tool to mask out parts of your model. Click on CMD and drag a rectangle. Try do this as precise as possible. Note: you could also mask the splitted area by the mask brush. It is up to you what’s the best way. You can change the masking option by clicking on CMD and changing it on the upper left side (below Projection Master).
Go to Tool > Visibility > Hide Part.
Delete Hidden Part
Go to Tool > Geometry > Modify Topology > Del Hidden > Close Holes. Once you’ve hidden the part, the model is open and the other part is only hidden and not deleted. This is why in step 1 you need to duplicate the model twice. Now you should have a separated piece of the model which is airtight.
Mask the other area of the model, or simply the same area. You can inverse the selection by cmd + clicking outside the model. And simply follow the previous steps again.
Go to Brushes > InsertHCylinder. [Shortcut for the cylinder is: B, I, Y]. Insert the cylinder on the model where you want it to fit on the other piece.
Now you still have a model that consists of two pieces. To make it one piece you have to dynamesh it. Go to Tool > Geometry > Dynamesh [Shortcut: cmd + drag outside the model twice!]. On the left upper side you can see ‘projection in progress’, after this process you’ve got one model and if you want more like these joints it is just a matter of adding another cylinder.
It is very important that the joint will fit on the other part, to improve this I usually smoothen the edges quite a lot to make it fit easier. To choose your smoothen brush, simply click on Shift and sculpt on the model. Also feel free to use the Polish brush which might be useful as well [Shortcut for Polish brush: B, P, O]
Once the separated piece consists of 1 piece and the joints are added, we need to inflate the part. Before doing this, duplicate the part and save it with a different name so you know this is one of the pieces to be printed! Step 9 is not mandatory but from my own experience I’ve noticed that you always need a tolerance. This tolerance is not too big if you are going to print it with an SLS or SLA printer, but it definitely is if you would like to have the end model printed on a desktop FDM printer. Go to Tool > Deformation > Inflate (x,y,z) by 5-10. (Do this with the duplicated model, not the one you renamed for 3D Printing)
This final step is crucial to make the parts actually fit on each other. I suggest to toggle the Transparency on (right bar below PolyF). Now it is a matter of placing the item with the joints right below the model you want to extract it from. Go to Tool > Subtool > Select the part with the joints > Shift-click on the ‘up arrow’ so it is above on your SubTool panel > Select the half moon (right next to the preview in SubTool). Select the part without the joints > Shift-click on the ‘up-arrow’ so it is on top of the other part. Go to Merge > MergeDown. Now go to Geometry > Dynamesh [Shortcut: cmd + drag outside the model]. This will give you the object in two separated pieces. One with the joints, one with the hole for the joints.
Update Size Ratio
Go to ZPlugin > 3D Print Exporter > Advanced Options > Select ‘Set selected SubTool size’ > Choose the units you worked with (mm or inches).
In the same menu select ‘visible’ and click on STL. Save your file and that’s it!
This tutorial was created during my internship at 3D Hubs. It was posted on the forum at 3dhubs.com and the model was uploaded to Sketchfab, see below.