We absolutely love new technology so when the opportunity to have a 3D printer in the office came along, we jumped on it. For our AuLaCart project we needed a custom case to protect the equipment and 3D printers are great for very small scale custom work.
In printing our first project, the AuLaCart case that is part of our recent patent filing, we quickly encountered our first challenge: just how slow this process can be. In our case the print time was well over 3 days and several of the parts had to be printed multiple times because of warpage. While the finished case looks like only two parts, the reality is that there are 8 parts that have to be ground down and glued together to complete the case.
In the learning process, it was interesting to discover that “solid” pieces are really hollow. When you slice the design from the stl file (design file) to gCode (printer instructions) it automatically fills large areas with a honeycomb structure to give it strength without wasting your expensive supplies. This improves the warpage that can happen when there is lots of material cooling at different rates. This may not sound like a big deal but we quickly found that temperature control is one of the biggest learning curves in 3D printing. Both the extruder and bed of the printer are heated and finding the right temperature settings can take time and a number of failures. The printer that we have is an open design so to control temp we ended up building a really “fancy” enclosure (implied sarcasm) from a cardboard box with a window made of shipping tape. While it may not be top of the line, it makes a big difference in the success rate of printing parts.
As we worked with the printer we experimented with various types of different materials such as plastic, polycarbonate, carbon fiber and even a type of wood. The most difficult by far was the polycarbonate, which is best known by the brand name of Lexan. This is a tough material and we never printed a successful part with this. The reason is that the temperature need for this specific material is 310c on the extruder and our printer will only go to about 290. That being said, the material never turned as liquid as we needed and therefor failed every time. Thank heavens, we recently we found a polycarbonate that can be printed from a lower temperature and we finally got a successful print.
One material that was especially interesting was carbon fiber and this material makes some really strong prints. The material itself is stiff and breaks easily from the roll. However once printed this is impressively strong material. To test materials we print small scale rocket ships. When using other materials it was easy to break parts off of the rocket ships however the carbon fiber rocket was nearly impossible to break (unless you are superman strong like my boss Mr. Bob, who was successful in breaking a part of my carbon fiber rocket). Carbon fiber is not the cheapest material you can print with, but if your print needs to stand up it is a good choice.
So far, our only production work has been the AuLaCart case and, because of the size, it was printed in 8 pieces and had to be glued together. 3D printing is not as accurate as conventional machining of a part so when it comes time to fit parts there is a fair amount of hand work on anything with tight tolerances. In our case, all the edges that were to be glued had to be flattened to get an edge that would glue properly and result in the right size of the final part. The printed surface is rough and needs to be treated if you want smooth surfaces. The only surface that gets a smooth surface is the one that attaches to the printing bed so you might want to consider that when you position the piece for printing.
The bottom line with 3D printing is that it is a very cool and interesting technology that works best when hot. We are now discussing ways that this new ability might be beneficial to our clients so if you have a thought for using 3D printing in marketing, please let us know.