Stereolithography (SLA) is perhaps the original 3D printing process and is used to manufacture a wide range of applications, from form and fit prototypes to fully painted display models. SLA provides complex and involved shapes quickly via a vat of liquid resin and a UV laser. The laser cures the liquid in pre-determined patterns layer by layer. It’s an economical way to build prototypes, which is why FLIR uses Stratasys Direct Manufacturing’s SLA process to prototype and predict success and failure in their products.
For FLIR’s MD-10 series of nighttime boat cameras, SLA prototypes were used to predict the way the camera would function five years down the line. They subjected their SLA prototype camera housings to a series of shock testing and took the SLA prototypes on the water for real world testing as well.
“The great thing about SLA plastics is that they are strong enough to endure vibration testing to a certain point,” says Marcel Tremblay, Director of Mechanical Engineering at FLIR. “We used the SLA prototype for water, precision of alignment and vibration testing.” FLIR used Stratasys Direct Manufacturing’s SC 4500 resin for their prototypes. SC 4500 is an excellent multipurpose resin with good accuracy.
“In the injection molded final product we know the unit will last past 1000 shock no problem,” says Tremblay. “But, maybe five years down the line, the shock might cause it to break. By testing with the more fragile SLA unit, we can get an excellent idea of where the part might break down the road. Then we reinforce it in the problem areas, thereby avoiding the breakage early on and giving the product longer life. While we had successfully predicted where it might break, it was extremely important to confirm exactly where the weak point was.”
FLIR begins prototyping with 3D printing early in the design process.
“At FLIR, we never release a production of a plastic tool without doing an SLA prototype first – never,” says Tremblay. “We always 3D print before we do any and all the testing. It’s a rule, simple as that.”
The SLA prototypes were invaluable in determining ways to better protect FLIR’s thermal imaging camera, which is housed within the unit. The camera was taken out on the water in the SLA unit and air and temperature were taken throughout the day in order to discover ways the unit could more effectively defend the camera against weather and sun.
“It’s so much better to do real testing,” says Tremblay. “We can do analysis, but there’s nothing like the real part.”
The SLA prototypes helped the team figure out how to route the cable harness for the camera, how big bends should be and how long and cable length and routing adjustments, all of which were important to finalizing the project. The prototypes were also used to organize and prepare the assembly line once the camera unit had reached the injection molding phase. Tremblay gave prototypes to FLIR’s sales force as well for valuable design feedback that determined the end look of the MD-10 series.
“During the deign process, we printed the units and gave them to our sales force,” says Tremblay. “We got their feedback and confirmed that the design met what they wanted. Our sales team was then able to show the unit to our key customers and ask, ‘What do you think?’ We got feedback that improved the design, and that was very good.”
FLIR printed over 15 SLA prototypes throughout their design and testing process. Tremblay’s team also printed flexible gaskets and seals for water testing to figure out any further issues, as well as to confirm logo placement and other aesthetic features. Stratasys Direct has a full-fledged professional finishing department that delivered SLA prototypes emulating the look of injection molded plastics.
The MD-10 series looks great, and will have a longer life on the water thanks to the genius of Tremblay’s team and their extensive prototyping with Stratasys Direct.
