Printing With Metal Inserts
The complexity of a part sometimes requires us to split it into components before 3D printing. Several techniques are used to fasten these components; metal inserts being one of the popular ones.
Let’s take an example of the tripod holder with an embedded nut as shown to the right. When designing for embedded parts, tolerances play a major role. We must keep in mind both the part tolerance (nut) and the tolerance/accuracy of the printer.
In this model, we are using an M5 hexagonal nut. The dimensions of the nut cavity are calculated based on the measured dimensions and a tolerance of about 0.5 mm is added on each side.
The nut dimensions can also be found online on McMaster-Carr.com but it is recommended to take the measured dimensions of the nut being used to avoid any tolerancing errors.
When the embedded nut is needed not on the surface, but inside the model, the print needs to pause in between to allow us to insert the nut and then resume printing. We can either manually enter a command on the controller or include it in the g-code to pause the print at the required layer.
- Find the layer after which you want to pause the print from the slicer visualization.
- Once you know the layer, search for it in the g-code.
- For Duet firmware, enter or add ‘M25’ to pause the print.
- For Marlin firmware, add ‘M226’ to pause the print
- Once the print is paused, insert the nut and hit resume on the controller.