Case study

Protolabs supports the development of critical safety equipment


Canute Rail worked with Protolabs to design and CNC machine a high precision part for critical track inspection work.

Inspecting new and repaired rail track is a safety critical operation that needs both specialist skills and equipment. It is an operation that you cannot get wrong.

With each length of track up to 120 metres long, even the smallest degree of misalignment or faulty welding is magnified along its length and could prove dangerous for rail users.  There is simply no room for error when installing new or replacing old track.

Knut Holen has worked in the rail industry for more than twenty years. He set up Canute Rail to provide track maintenance and inspection work for Norwegian rail. While he currently operates as a sole operator, he is looking to expand his business.

When Canute Rail needed to develop a highly accurate part to meet Norwegian Rail’s strict criteria for its weld inspection and rail alignment kit, Holen turned to Protolabs for help.

“I could not find another supplier that could produce the part we needed to the accuracy and quality required.  Protolabs made the whole development process simple and fast,”

“The rail authority provided me with a schematic drawing of the part, from which I produced a CAD.  I uploaded this directly into Protolabs’ software which automatically checked it for design for manufacturability and provided a quote within just a couple of hours.  While I didn’t need to make any design modifications, when you are a small business it’s still good to have confirmation that the part’s design and its parameters are possible using CNC machining.”

cnc machined part for critical track inspection work

Canute Rail only needed one part for its weld inspection kit, but this part required precision engineering measured in microns to achieve the required accuracy. The part itself fits across the weld and Holen uses it to check the geometric tolerance between the two rails using the part and calipers, since even the slightest deviation is serious when magnified along the length of the track.

With Protolabs’ quotation, design approval and production process digitised, Holen could manage the whole process himself from his PC, from quote and checking the CAD for manufacturability, right through to placing the order.  While an account manager from Protolabs was there to help and advise, the whole process was visible from start to finish from his own office.

Automating the process also meant that Protolabs could produce the part quickly and ship it at minimal cost.

cnc machined part for critical track inspection work

The part itself is part of a bigger welding and rail alignment inspection kit.  It is manufactured from aluminium since Holen needs to carry the kit on his own and often needs to walk to site.

“Unfortunately rail track is not always close to a road, so sometimes you might need to walk a few kilometres to get to the section that needs maintenance work and inspection.  It means that the weight of the inspection kit is critical, which is why we decided to use aluminium for the part since it is light, can be machined to accurate tolerances, and is reasonably durable,” said Holen.

The company is planning to develop more tools for inspection in the future and will turn to Protolabs for their help.

Holen continued: “When you are a small business tasked with developing highly specialist parts for safety critical applications, it is important to find the right outsourced manufacturing partner.  The great thing about using Protolabs is that you are in control of the process.  You can upload your CAD and their software will analyse the design and highlight if any changes are either recommended or needed.

“There is also no minimum order quantity, so it’s ideal for me since I only wanted a single high precision part.  It’s a great service for small businesses when you need to outsource manufacturing and to control and understand the process.”

Protolabs’ digital platform for quoting, design analysis and ordering parts is suitable for both rapid prototyping and on-demand manufacturing.  Manufacturing services include injection moulding, CNC machining and 3D printing. It is ideal for small businesses and startups and for larger manufacturers looking for rapid prototyping or outsourced manufacturing for small- to medium-sized production runs.

It gives visibility right through product development and manufacturing with full control of the process from your own work space.