Alcon

Eric Huang

We were confident that our automation would be built perfectly after we had provided all the CAD drawings, models, and the actual injection molded parts to a top-notch vendor. The day we took over the machine at our lab, I thought that once I started the process, I could go and get a coffee; after my coffee chat, all the parts would be ready for me on the shining trays in a mobile cart.

It turned out that I could not even walk out for one step. The station where the parts were placed from the suction cup to the butterfly unit got stuck very quickly. I moved to the location where I could have a good view of the process, and then I noticed that one part was not fully seated and pulled up again by the suction cup. A thought flashed through my mind: the parts were hot from the molding machine, while the suction cup was designed according to the cooled part. No wonder the clearance was reduced too much and not able to provide a clear drop.

By enlarging the suction cup’s inside diameter, I thought now it would have no more problems. But I was wrong. When I started my DOE, eagerly making changes and adding hundreds of bars on hold pressure, then the same problem came again. I patted my head; how could I forget that the hold pressure increase would make the parts larger?

"A Design Review Meeting Should Not Be A One-Time Deal; A Continuous Conversation Could Help Optimize The Design Along The Way"

These were not the only issues encountered; other issues, such as the height of parts at release, were not optimized; if they were too low, the parts pulled up again, and if they were too high, the parts wouldn’t seat well. Also, transferring the parts to a tray put too much force and generated fatigue on the supporting arm. All these little things add up, and we must spend lots of time re-working.

So why this happened? First, on our end, we did not know the design enough and did not envision what information was important to provide. On our vendor’s end, standard communication was far from enough. Maybe one person is missing: the person who knows automation and molding of the products. A design review meeting should not be a one-time deal; a continuous conversation could help optimize the design along the way. More importantly, it will help both sides understand each other better. Imagine the time saved and the hassle disappeared; then, I can have my coffee chat.

We all have something to be proud of, and that is really a good thing. And if we acknowledge the others what they are proud of, maybe we can learn more and make our job better and faster.