Lattice Knife Handle
This knife handle, designed in nTop and 3DXpert and printed on a DMP 350, showcases the unique possibilities of additive manufacturing. The intricate cell structure delivers a striking aesthetic that’s impossible to achieve with traditional methods and provides an improved grip texture.
Inspiration
This project was inspired by the countless designs of knife scales I saw during my visit to Spyderco. I was fascinated with the intricate models and creativity of the designers. That’s when I got the spark to make a 3D printed design for the Mule Team blade.
Design
With design tools in hand, I got to work and created a base model in SolidWorks with Isaac Chase and Tom Powell. The profile was created using the loft tool to give the handle the curvature for a better feel. After a few iterations of ergonomic prototypes printed in plastic, the design was ready to be latticed.
Lattice Design
The lattice design was created using the Voronoi Volume Lattice block in nTop with a random point spacing of 2 mm and a thickness of 0.6 mm. These parameters are based on the 3DSystems design guide for overhangs taking into account the randomized orientations of the lattice strands.
The stochastic lattice created in 3DXpert by Isaac was optimized using a smoothing algorithm and oriented based on the build direction for best printability. Additionally, the lattice section of the print was printed with the lattice printing parameters.
Manufacturing
The parts were sliced in 3DXpert and printed on a DMP 350 Powder Bed Fusion - Laser Beam (PBF-LB) printer from 316L stainless steel. A vertical orientation was used to minimize the residual stress and support structures. Wall supports were applied at the base of the handle to maximize the heat flow and allow the parts to be removed manually. Power supports were utilized for the circular holes to improve the dimensional accuracy for successful thread-forming.
Results
Stochastic Handle made with 3DExpert by Isaac Chase
Voronoi Handle made with nTop
Both 3DXpert and nTop can create intricate lattice designs with hundreds of options. For a project like this there is no significant difference between which software to choose because the purpose of the lattice is for aesthetics and feel which are highly subjective.
The two lattice structures printed successfully with a unique surface finish and feel. The texture of PBF-LB is often undesirable due to the rough surface's negative effect on mechanical properties. However, the sandpaper-like feel is a benefit for this project because it makes the blade feel more secure in the hand.
This project is a demonstration of advanced manufacturing techniques used to create an elegant design with enhanced functionality.
