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Not for Everyone

March 30, 2015

Filed under: 3D printing,additive manufacturing,CAD/CAM/CAE — Terry Wohlers @ 10:22

Contrary to what some would like you to believe, owning and operating a 3D printer is not for most consumers. It may be easy to buy one, but it’s definitely not easy to create the 3D model data needed to produce a unique design. Also, getting a satisfactory result from a 3D printer is not fast or straightforward.

I’ve owned a pair of downhill (alpine) ski poles that I cannot easily replace. They have molded grips that the ski industry stopped producing more than 10 years ago. I like the poles, but the plastic parts near the tips (called baskets, as shown in the following) are ripping apart. So, I decided: Why not replace them using our 3D printer?


Student intern Tyler Hudson, who graduates in May 2015 with a degree in mechanical engineering, learned SolidWorks some time ago, so he produced a solid model of the basket design. Learning to use SolidWorks or another professional-grade CAD solid modeling product is not trivial. Tyler did an excellent job with the basket design, but my guess is that 99% of average consumers would quickly become frustrated with the effort. And, this assumes that they have access to good CAD software.

Tyler printed the first version of the basket in ABS plastic using our UP! 3D printer. It turned out well (see the following image), but the plastic was much too rigid for this application. The basket design snap fits into place, so it requires a flexible or semi-flexible material. We knew about the NinjaFlex materials and contacted the company, which was kind enough to send two spools of 1.75-mm diameter filament. The thermoplastic polyurethane (TPU) NijaFlex material is very strong and tough, with high tear resistance. We later discovered that our 3D printer does not support the higher temperature requirements of this material, so running it on the machine was not an option.


Colorado State University, in Fort Collins, has an Idea-2-Product lab with several 3D printers, so we contacted the lab to see if it could run TPU material in one of its machines. We learned that it had a LulzBot printer from Aleph Objects that was already running black NijaFlex material. Tyler visited the lab and spent hours getting it to build properly, partly due to his unfamiliarity with the material and its slow build speed. Eventually, he was successful, and he delivered the new baskets to me the evening before our ski weekend. The baskets turned out well and they performed as expected on Saturday and Sunday at Copper Mountain.


Most consumers would not have been able to produce these relatively simple parts. Creating the data would have been the first obstacle, and then having the right 3D printer and material would have also presented challenges. What’s more, the cost in time would have easily exceeded the cost of buying new poles or buying used ones (with the preferred grips) online. We went into this fairly small and simple project hoping that it wouldn’t require a great deal of time and effort, but also understanding that it could. It turned into a time-consuming effort that spanned more than a week, required a lot of skill and experience, and access to a special 3D printer and material.

Wohlers Park

March 14, 2015

Filed under: travel — Terry Wohlers @ 10:34

I had heard about Wohlers Park in Hamburg, Germany many years ago, but did not visit it until last week. Thanks to Prof. Dr.-Ing. Claus Emmelmann of Laser Zentrum Nord GmbH for taking me there. It’s unclear whether our family is connected to the park, but there’s a reasonable chance. My great, great grandparents lived in Northern Germany prior to immigrating to the U.S. The following sign is at the entrances into the park.


The German writing translates to: The former cemetery Norderreihe was renamed to Wohlers Park due to its proximity to Wohlers Ally. The cemetery was opened in 1831 by the protestant-Lutheran parish St. Johannis to Altona/Elbe. The last burial took place on 11 October 1945. The area of the park was subject to conservation green spaces and recreational sites by law and has been open to the public since 1977.


The previous image is at the park’s most active corner. We could not resist a visit to the pub named “Wohlers” for a good German pilsner. That’s me standing near the entrance, and Claus holding the pub menu.


For more on the beautiful city of Hamburg, see this 2.5 minute video. A good friend from Hamburg sent it to me this week. And, if you’re ever in Hamburg, I hope you stumble across Wohlers Park, Wohlers Ally, and Wohlers pub.