Keeping Trains Moving With Silicone 3D-Printed Parts


Train maintenance problems are becoming commonplace due to parts shortages and manufacturing constraints. Grounding a train is the last resort, but operators are faced with no alternative if serviceable parts are unavailable.

A railway sector company recently faced this problem when the silicone boot seal for a train braking system got damaged and needed replacing. Boot seals are not readily available, and the company couldn’t source one.

This led them to pursue a manufacturing solution for the component, but injection moulding lead times were weeks or months. Research led them to Lynxter and its 3D printer, the S600D, which can 3D print liquid silicone.


3D printing silicone boot seals

A boot seal protects a train’s braking system from the elements, dirt, and oil. It is a critical maintenance component and usually only needs replacing every six months, but unforeseen damage put it out of commission.

The train operator turned to Lynxter’s silicone additive manufacturing technology to manufacture the part. Fitted with the two-component liquid extrusion tool head, LIQ21, the S600D printed the boot replacement within a few days.

Further reading: Who are Lynxter?

However, the first model had problems – the original digital scan for the part had tolerances for injection moulding, which are incompatible with 3D printing.

The company made minor adjustments to the 3D design in CAD to accommodate the print head’s mechanical nature. After inspecting the issue, it became clear the S600D was printing unsupported layers of silicone, compromising the part’s stability.

One of the solutions was replacing a 90° overhang with a 45° chamfer so each layer could rest on a layer underneath. By tweaking the 3D file, Lynxter and the railway operator could create an accurate replacement part.

If the railway sector company had waited for an injection-moulded part, it would have taken several weeks to arrive, impacting train schedules. With the Lynxter S600D, they solved the problem in a few days and have a valuable manufacturing tool for future maintenance.

The Lynxter S600D utilises FFF (Fused Filament Fabrication) and LAM (Liquid Additive Manufacturing Technology) to print an enormous range of materials. You can print silicone, carbon PA, PP, PEKK, aluminium filament, polycarbonate, TPU, clay, porcelain, PP glass fibre, PCL and many more materials by swapping out tool heads.

To find out more, you can request a sample, contact us, or

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This story was originally published on the Lynxter blog.