Student Case Study: 3D printed saw handle.
- jonathang22
- May 15
- 2 min read
Updated: 7 days ago
By Jordon: Selkirk College Student of the Digital Fabrication a Design program.
The Client, Bruce, had his pull saw break during use, the original part was an injection moulded saw handle with a push button blade release, the two halves of the saw handle were held together with only 2 plastic pins leading to the failure of the part. Bruce wanted a stronger part with a simpler blade attachment method. He asked for a customized grip inspired by Japanese wrapped bamboo handles. Bruce also commented on the original’s nail hole being too small to hang the saw when not in use.
We chose to 3D scan the part and reverse engineer the design. The part was printed in MJF nylon PA12 to allow for internal voids to reduce material needed while allowing the part to be made in one piece to add to the strength of the part. MJF technology was chosen over the original injection moulding to allow for more complex geometry and reduce waste, along with the cost difference for custom one-off parts. To further reduce waste, prototyping was done in FDM PLA to ensure that everything would fit in the final part. FDM was not chosen to be the final technology because of layer adhesion and support issues.
Nylon was chosen over the other materials for the lower cost and higher flexibility to reduce the chance of cracking in the future, 3D printing allowed for part personalization with out making custom injection moulds. The part was printed hollow with 5mm wall thickness to balance strength and weight.
Bruce was happy with the results of the repair and the feel and quality of dye used on the nylon. My design was not completely optimized for MJF printing, I had some semi-blind holes that trapped powder and made it difficult to clean and dye evenly. The nylon did offer greater strength and flexibility as expected and should result in a long lasting custom tool that can be handed down for generations.
