Tuesday, May 4, 2010

How do we use 3DP in our development process?

When I first started here at Z Corp. some 5 years ago I was very familiar with rapid prototyping. Having been involved with new product development in one form or another for nearly 20 years, I thought I understood how prototyping could be used to improve the final design and to get to market faster. It didn’t take long to realize that the prototyping environment was changing fast and that RP and 3D printing in particular could be used in more ways than I had previously thought.

Although the R in RP stands for rapid, what constitutes “rapid” is relative. RP parts (SLA or SLS) from a service bureau typically take two to three days or longer to receive. And, although they are usually worth the cost, they aren’t all that cheap. As the capital cost of equipment comes down and more companies bring RP in house, the usage has gone up. Needless to say, as one of those equipment manufacturers, we have in-house capabilities. So, how do we use those capabilities in our development process?

I thought that instead of listing all the ways we use 3D printing in our development process, I would share some examples that I find particularly useful. One of the first projects I worked on at Z Corp. required the redesign of a small plastic injection molded part. The task was simple but required a modification to the mold. In the past I might have used a prototype to check the modifications before ordering an expensive change to the mold. In this case I did that but I also printed a part two times larger than the actual size and annotated the changes with arrows and text that clearly showed the changes right on the part. I sent this part to the mold maker and he was blown away. The communication about what had changed was clear and he was able to better visualize what needed to be done to the tool and how that would affect things like mold flow and venting.

Another example I find interesting is prototyping rubber-like parts. Again, in the past, the process from a service bureau might have looked like this: create an SLA of the part, cast rigid urethane around the part to create a mold and then pour soft durometer urethane into the mold to create the final part. In developing a new print head parking station, I quickly realized that printing the actual mold and skipping the first two steps in that process had become common practice at Z Corp. I used SolidWorks mold creation tool to design the mold. I then printed the mold, sealed it with mold release, and poured the urethane directly into it. What I love about this process is that I don’t have to wait a week to find out the design isn’t quite right or that I need a different durometer.

One last thing worth mentioning is using 3D printed parts for functional testing. The example that stands out in my mind is a six-port vacuum valve that is used in all of our new ZPrinters. The concept was simple, but the design was novel, and we had no idea if it would actually work as intended. It involved a gear, an inlet port, and six outlet ports. The idea was to rotate the inlet port to the appropriate outlet port to direct vacuum to the appropriate location in the printer. The components were printed, refined and reprinted. After several iterations the design was finalized. Before spending money for plastic injection molds, we printed several valve assemblies, installed them in printers and ran them for several months to test functionality and overall performance. The testing results gave us very high confidence that the final valve would work as planned.

What I am curious about is if you have in-house capability, how do you use it? And, if you don’t have an in-house capability, how do you use RP in your process and how do you think it would be different if you had a 3D printer in house?

No comments:

Post a Comment