3D printed replacement parts by Stratasys for Angel Trains, certified for use by regulators [Source: Fabbaloo]

I spent some time speaking with Yann Rageul, Stratasys’ Manager Strategic Account Team, EMEA, to find out more about the company’s recent moves in digital inventory for the transport industry.

Stratasys Transition

Stratasys is in the midst of a big transition. Their initial market, which served them very well for decades, is shifting due to the competition opened up by the cascading expirations of Stratasys’ original patent portfolio. They managed to acquire another set of patents with the Objet merger, but they need a new gig for the long term.

They seem to be working on an interesting strategy involving digital inventory, particularly in the transportation industry. If successful, it could be a massive market for them in coming years.

Digital Inventory

“Digital Inventory” is a concept where a manufacturer no longer maintains a warehouse of spare parts, and instead uses digital manufacturing — often including 3D printing — technologies to quickly produce any required spare parts on demand. This, at first, makes a lot of sense, as you would shed the cost of warehousing and also be able to produce only the parts actually required, rather than guessing and making too many.

That’s critically important, because the manufacture of the original parts was done when the factory tooling was set up for those parts, likely years ago. When the manufacturing line is making the production parts, the manufacturer simply lets it run a bit longer to make a pile of spares before shutting down the production line forever.

Restarting the production line later to make a few new spare parts is ridiculously expensive and is entirely infeasible, both in timing and cost.

Transportation Industry Digital Inventory

Stratasys has correctly identified the transportation industry as particularly suited for digital inventory. This is because many of their assets — airplanes, rail cars, ships, etc. — are extremely long lived. It’s not uncommon to see aircraft 20 years of age, or rail cars even 40 or 50 years old.

Imagine you’re the manufacturing manager 50 years ago and trying to guess how many spare parts you should produce for the next FIFTY YEARS! Basically, you have no idea, just make a bunch and call it a day. It’s someone else’s grandson’s problem.

Rail Spare Parts

3D printed replacement part by Stratasys for Angel Trains [Source: Fabbaloo]

What do these rail car operators do when the original spare parts inevitably are all used? According to Rageul, they start scavenging on spare rail cars that are not yet in service (yes, whole extra rail cars are also produced). But the parts being required are typically not the wheels or undercarriage, instead the high-demand parts are those abused by the passengers.

We’re talking handholds, steps, shelves, etc. Any sort of plastic bits that you’d commonly see on a rail car. They tend to break frequently because of human abuse. People drop heavy suitcases on them or stand on them and the result is often broken parts.

The other option for the rail operator is to have the parts specially produced. However, that usually involves re-design, milling/molding and finishing that is charged at highly exorbitant pricing by suppliers because there’s such a low volume. There’s also a very long lead time involved. The rail operators are in a bit of a bind here.

Setting Up Digital Inventory

Stratasys hopes to solve the problem by organizing systems to enable rail operators to maintain a digital inventory approach. They have the 3D printers and the materials, so what’s holding up the show here?

That’s the challenge of Rageul, who is working as the point person for Stratasys with the rail industry. They’ve signed up a couple of rail suppliers for experimental ventures to see if this approach can be made to work. One of them, Angel Trains in the UK, has been working with Stratasys. Angel Trains supplies a majority of the train hardware to operators in the UK rail system.

By working through the entire sequence with Angel Trains, Stratasys will be able to deeply understand what it will take to perform digital inventory transitions in the rail industry.

Aerospace Digital Inventory

3D printed replacement parts by Stratasys for aerospace applications [Source: Fabbaloo]

To Stratasys, this is similar to the work they previously did for the aerospace industry.

They see the rail industry as a second iteration of more-or-less the same process, but with different content.

3D printed replacement hanger unit by Stratasys [Source: Fabbaloo]

For example, Rageul has been working with the various regulatory agencies to ensure the Stratasys materials are certified for use in the industry regarding fire rating, toxicity and several other certifiable aspects. That’s but one not-so-small step of many on the road to rail digital inventory.

Another step is to obtain the required 3D models for the parts. This is being done by actually 3D scanning “hundreds of parts”. Why “hundreds”? It’s because there turns out to be many different versions of apparently the same type of part. Essentially you’re bumping into a legacy of decades of part acquisitions by the rail supplier.

But having the digital inventory established is not quite the end.

Digital Inventory Opportunities

3D printed ULTEM replacement parts by Stratasys using FEA to minimize material and maximize strength [Source: Fabbaloo]

Many of the parts could be improved or even changed once they are digitized. Rageul says they are doing FEA on several parts to determine the optimum internal structures to match the expected loads. That way they the parts can actually be stronger than the original!

Interestingly, unlike the aerospace industry where lighter parts are considered quite valuable, this is not the case in the rail industry. Each rail car must maintain a certain weight on the tracks to ensure an appropriate amount of friction.

Similarly, the rail operator can now make choices about how to change the part. They could, for example, put braille markings on seatbacks to allow for a better experience for sight-impaired passengers. Many other possibilities are present, such as altered styling, or implementing USB chargers.

Stratasys’ next step is to set up an entire supply chain for this process. Once done they should have a very attractive proposition for rail carriers across the world, who no doubt have the same problems as Angel Trains.

Via Stratasys