3D Printing Optically Transparent Light Pipes with Nix and Formlabs

Nix 3D printing

Prototyping optically transparent components isn’t as easy as opaque ones. Traditional manufacturing methods like CNC machining and laser cutting achieve different levels of translucency, and greatly limit the possible geometries available. These manufacturing methods are also time intensive, with one prototype taking an average 4 days to complete.

Ontario-based Nix has found a solution to the problem. They use 3D printing to prototype light pipes and other optically transparent components. For this, they use Formlabs printers. Specifically, the Form 2 (although they started out with a Form 1+ when early-stage).

3D printing has allowed Nix to reduce costs from $150-300 per part for CNC light pipes to $0.32. That’s right – just over 30 cents. 3D printing has also introduced newfound efficiency to the manufacturing process. Parts that would normally take 3 days to manufacture can be printed in just a few hours. They are now able to design a prototype in CAD and make it in on the same day. This would be impossible with CNC machining.

3D Printing Optically Transparent Parts

Nix use Formlabs Clear Resin to 3D print transparent components like lenses and internal light pipes. Choosing the right fabrication method for this required many, many rounds of prototyping.

3d printing transparent parts

Nix tried laser cut acrylic, CNC acrylic, 3D printed molds, and directly 3D printed plastics. They landed on 3D printing (of the stereolithography kind) after trialling it. They found this manufacturing method produced the most accurate prototypes and, crucially, parts that were optically transparent.

“Formlabs Clear Resin helped us analyze the shape, design, and fit of transparent components. There wasn’t really any other option other than to 3D print in Clear.” says Matthew Sheridan, CEO & Founder, Nix Sensor Ltd.

3D printing lenses allows the team to have 10 different lenses on a single build platform in an afternoon. This ‘ workshop mass production’ is far beyond the capabilities of a CNC machine, especially when you consider the footprint of the Form 2. It literally fits on a desk and takes up no more space than a desktop computer.

Post-processing is limited to the functional, too. After printing, parts are washed thoroughly with isopropyl alcohol (IPA) using the Form Wash. Parts are then polished using sandpaper of various grits. The finished parts have transparency that’s similar to acrylic plastic. They aren’t completely see through, but they’re as close as you can get to it.

Here’s a photo of a part to show you what we mean:

Nix parts

Using the Form 2, Nix are able to fabricate optically transparent parts to a high standard. Keeping production in-house means costs are kept down and the team have full control over specification.

Importantly, the quality of parts is exceptional. Since using 3D printing, the team hasn’t seriously considered any other technologies. CNC machining and laser cutting work well (they’re tried and tested) but because they achieve different levels of translucency, and greatly limit the possible geometries available, they aren’t as flexible as 3D printing.

3D Printer: Formlabs Form 2

Materials used: Clear Resin.

This information was first published on the Formlabs website.

You can check out more engineering case studies like this one here.