It’s now been almost six years since we started offering White Strong and Flexible (WSF) to you, our community and it’s a good time to share what we have learned.
So, this is the first of a series of three blog-posts that I am writing about Strong and Flexible 3D-printing. Please share your feedback by commenting, we would love to learn your thoughts and ideas!
First and foremost we are extremely happy to see the result of what you have made with WSF and later the color variants (together called Strong and Flexible Plastic). Over the last six years we have printed more than 2.5 million parts in Strong and Flexible. These part range from jewelry to cases for the iPhone, quad-copter accessories (see picture), to the fabulous Animaris Geneticus Parvus (see picture), lighting shades and more. White Strong and Flexible Plastic and the colors have been and are still by far the most popular material on Shapeways.
Let me share what it means to make something in Strong and Flexible Plastic. The current system on Shapeways is based on files. After you buy 1 or more copies of a product represented in a file, the work for us starts.
First, for new products, we have to check whether the products in the file are printable. Are the printers capable of producing the details? Are the products strong enough? Are the walls thick enough? Checking each new file is done by software and by hand to make sure you get what you want. If we believe we cannot print something, our team makes a clear report about the issues, including screenshots. As you can imagine this takes quite a bit of time. The checking and rejection process has become quite a challenge, more about this in the post next week!
After checking we plan the files into the tray of the machine. Depending on the size of the machine, each tray can hold hundreds and sometimes thousands of products. If the files hold multiple parts, here’s where it becomes hard. We sometimes need to increase separation of the parts (to prevent them to melt or fuse together) or reorient or simply separate them to optimize maximum tray fill. As we put more parts in a single tray, it increases the efficiency of the print run and in turn enables us to offer reasonable prices.
Now that we have planned the tray the file containing all parts for the print, called a slice file, is sent to one of our big SLS printers (picture below shows one of our massive EOS P7s). One printing run typically takes 24 hours, but our big P7 machines can print for up to 3 days! When the printing is done we quickly remove the full tray to let it cool. Cooling takes as much time as printing.
After the tray is cooled down to room temperature, we retrieve the parts from the tray, which is now filled with nylon powder and parts. Digging the parts out of the powder one by one is actually a super fun process. You never know what you are going to find! The hardest to find are the very small parts, since distinguishing them from little plastic lumps is challenging. At one time someone tried to print parts as small as 1x1x1 mm!!
Now we need to remove the excess powder from each part, which is done with compressed air. Then we sort all parts. Some will be ready to go to our packing stations and be shipped, while others need post production. We either polish (see pic below of our polisher), or polish and dye the parts. After each step we need to sort again, since polishing and dying puts all parts together in batches again. So we spend a lot of time sorting parts and luckily we have gotten quite good at it ensuring everyone of you, our customers, get the right parts with the right finish. Files holding multiple parts are hard to sort. Our systems use the file as the unit and if it contains multiple parts its hard to recognize and to make sure we have all parts. Some files hold over 100 parts and even counting them takes a lot of time!
We can typically do all the above steps in less than four days, which is quite miraculous given the amount of time the printing itself takes. Once all of these steps are complete, the products are ready to ship and are collected in the distribution wall of bins (see picture below). When the order is completed, our distribution team packs them up and sends them to you our customers to enjoy.
Next week I’ll spend time diving a bit deeper in the specific challenges we face and how they influence the cost of 3D printing in nylon using Selective Laser Sintering.
Please feel free to ask questions in the comments below, or make suggestions for the deeper dive next week!
all the best,
Pete / CEO Shapeways