Titanium Jewelers Saw
Titanium 3D Printed Jewelers Saw
While interning at Boeing's Additive Manufacturing and Prototyping Lab, I got the opportunity to work on a project of my choice to learn about the different manufacturing processes at the lab. Due to this being a personal project it is not covered by my NDA.
For my project I decided to make a lightweight jewelers saw. A jewelers saw is a small handheld saw typically used to cut thin sheet metal or for precision woodworking. Most jewelers saw frames are flimsy and not very stiff. To create a lightweight but stiff saw frame, I used topology optimization to reduce the saw frame's weight while optimizing it in terms of stiffness based on the expected cutting loads on the saw. For the saw, I designed multiple different handles including a SLA printed handle and a grippier casted polyurethane handle.
The Design
DMLS Saw Frame
The saw frame was made out of titanium using Direct Metal Laser Sintering. The saw frame was designed using topology optimization to make the saw frame lightweight but stiff.
SLA 3D Printed Handle
For this saw handle it was made out of Somos NeXt using a SLA printer. This handle was designed to be lightweight and to be able to be printed without internal supports.
Resin Casted Handle
For this saw handle it was made using a PLA 3D printed core with a polyurethane rubber grip casted around it. This handle was designed to provide a nice grippy texture to make it comfortable for long duration use.
Machined Blade Holder
To allow for the saw blade to be tensioned, a small machined blade holder was made to fit into the saw frame. This blade holder is held in place and tightens the blade through using a thumb screw on the front of the saw.
Saw Frame Design/Manufacturing Process
The basic saw frame shape was CADed in CATIA and imported in Altair Inspire.
The exported cutting forces were applied to the saw and the frame was modified using topology optimization.
Using the expected cutting forces, a simulation was run to see how much the saw frame would bend.
A PLA prototype was printed to verify and check the saw frame's function and ergonomics.
The build file and support structure was designed in Materialise Magics.
A print simulation was run in Simufact Additive to see how the part would deform to further improve the support structure design.
The saw frame was printed out of titanium on a SLM 280 DMLS printer.
The saw frame was post processed and assembled into the final product.
Resin Casting Saw Handle Process
The mold was designed and printed out of PLA.
A PLA handle core was inserted into the mold. The core features multiple holes and taper to provide mechanical bonding for polyurethane.
The polyurethane was injected into the mold and the handle grip was casted.
Multiple mold and handle iterations were designed and casted to further improve the design and reduce defects.
SLA 3D Printed Saw Handle
The SLA 3D Printed handle was designed in CATIA. The goal of this handle was to design a lightweight handle that showcases the printing abilities of the SLA process. The handle has a hex lattice structure to make it lightweight. To ensure the handle could be printed without supports on the inside of the handle, a cylinder was designed into the middle of the handle with 30 degree tapers at the top and bottom.