3D Printed Flexible TPE Lattice Cube  


Haozheng Zhu
In order to design shoes with lattice structured sole, I have made a pilot test, to see if FDM printing with flexible TPE material was suitable for the making. I used Rhino5 with grasshopper and a plugin called IntraLattice from MIT to make the lattice cube model. During the basic 3D printing workshop at PlugnMake FabLab Delft, a lattice cube with cross unit pattern was successfully printed in PLA material in 30 minutes. It was a good starting point:
3D printed PLA lattic cube

PLA Lattic Cube 22X22X22mm printed during the basic 3D printing workshop at FabLab Delft

Then, with support from Mario, we tried 3 times to print the TPE version by one of Builder 3D Printers. Although the results were better as we kept on testing, we should further test the material.
close picture of the printer working

First test print

4 different 3d printed test compared in a picture

Overview of the test prints

Remarks:

– TPE is a kind of very soft and elastic material. Set up  carefully the printing settings. So far, it’s good to know that at 20mm/s printing speed and 220℃ printing temperature, the TPE material flow goes well. Further exploration of settings is needed. – And with a dual-feed printer, it’s good to put the same filament in both inputs, even if you use only one of them. – Before starting a print, you need to clean the nozzle to be sure it’s not blocked. If the flow is not going well, clean the nozzle again.
Here I want to emphasize that the 3D structure itself has a drawback for 3d printing: if you look at the 3D model in Cura with layer view, every slice is kind of a dot pattern. This means the printer has to pause the flow frequently while printing. But in these phases, material dropping from the nozzle will spoil your print on the bed.
a screenshoot of the slicer software

The blue lines (travelling nozzle) are the pause moments of the material flow

For TPE, THIS is the issue that made the test fail. When printing the base of the cube, the TPE flow with line pattern was fine. But when it came to the dot pattern, printing became chaos.
TPU fault print

Too much pause moments and dot pattern make it not good for FDM TPE printing

Mario suggested me to change the design to ‘Tetrahedral’ 3D infill structure in CURA, because it’s kind of lattice pattern with line pattern in layers. Let’s see what will happen next time!
screenshoot of the slicing software showing the Tetrahedral infill

‘Tetrahedral’ infill structure for the next test

Thank you for reading!

Leave a comment

Your email address will not be published. Required fields are marked *