What I see as a user of public transport is that during the holidays often fewer trains or buses are on service. This makes sense since a lot of people are having holidays, schools are closed, so the frequency of public transport services can be minimized during these weeks. I can imagine that the public service companies use the weeks to make repairs and replace worn parts in the vehicles. I can only imagine what a disaster it would be if due to for example holidays a specific part can not be replaced in time, ending up with downtime in the production process, extra costs, or even worse, the worn part you need a replacement for is no longer in stock or even available. This blog post is about replacement parts, which are slightly different than spare parts. A replacement part is a part that can be used as a spare but has a different part number. A spare is a replacement of a defective part, but with the same part number. Since most of the 3D printed examples below replace conventionally manufactured parts, they are all called replacement parts.
The first example of a 3D printed replacement part is a 3D printed grab handle for an in-service passenger train, manufactured by UK-based Angel Trains. 3D printing gives the company huge benefits. As you can read on their website, ‘they have been able to create a digital library of many of their parts and assets. These digital files can be easily edited and improved upon, before being physically prototyped using 3D printing. By using AM, Angel Trains can manufacture short production runs quickly and cost-effectively, reducing the need for large minimum order quantities or storage of spare parts. They can produce parts that are cheaper, lighter, and more customized, enabling them to better manage the replacement of obsolete parts and the fitment of modifications, delivering benefits to both operators and passengers.’
Also, UK-based Additive X comes with a success story on 3D printed replacement parts. One of their customers, a European pet food manufacturer, struggled with obsolete parts in their equipment. Their equipment was fitted with legacy parts that could no longer be sourced. These were breaking regularly causing downtime in the process. As you can imagine the customer was interested in 3D printing as a way to manufacture parts for their machines in-house. The part on the left is a repaired packaging arm that was no longer available off-the-shelf; the two black parts are 3D printed in Onyx and isotropic reinforced carbon fiber. Based on the original metal part a digital replica was made and 3D printed. Without the need for post-processing, the parts were slotted into the machine perfectly and were put to work. They lasted four months before showing any signs of wear, whereas the original metal parts only lasted a few weeks.
Another example of 3D printed replacement parts is from Ashley Furniture. Their question was if it would be possible to replace machined alignment pins with end-use 3D printed parts, avoiding the long lead times and minimum order quantities of outsourcing? As you can read on the website, yes, and much more! It not only increased their production by 10% with almost 15% less labor; what I like about this example is that employees across the company continued to ask questions and pose ideas, and the company continued to grow. The example in the pick is a vacuum retainer ring for a point-to-point drilling machine that couldn’t be purchased on its own, the only option was to purchase the whole assembly (see top image), which was costly. Instead, the company 3D scanned the part to capture the geometry, and 3D printed a replacement part for only $1 to keep their drilling equipment running, without having to buy the complete assembly.
Also, Daimler Buses took advantage of 3D printing’s customization capabilities to produce small batches and replacement parts. Based on the needs of their customers, Daimler can now 3D print customized special equipment features or replacement parts in a more economical way. By adopting 3D printing, Daimler is also enabling customers to re-order parts produced with 3D printing using a specific part number, specified in the Daimler order code lists and replacement parts catalogs.
Also, Mercedes-Benz Classic uses 3D printing for replacement parts of their more classic cars. Some of the spare parts are being replaced into 3D printed replacement parts. I can only guess for the reason why: some parts are not being manufactured, to save inventory space over time, to print on demand, to improve the service to customers by sending digital files to local 3D printer service providing better and faster service? The 3D printed spark plug holder (replacement part number A198 580 00 65), made from PA12, includes a modification that is made possible thanks to 3D printing: instead of using a female connector, the spark plug is now securely held in place by a magnet. This means the holder can now be universally used for all spark plug types with and without SAE terminal nuts. And like in this example, to improve the part in its function thanks to the freedom in design when 3D printed.
Each of Tessa’s weekly picks is a curated group of 3D printed designs, based on the week’s chosen theme. If you would like to offer a theme for Tessa, or if you have your 3D printed weekly picks you would like to see featured, please let us know by commenting below. Subscribe to the newsletter to get the latest weekly picks every week in your mailbox.