Caterpillar uses a FDM check fixture to cut rework time

In this second of a three-part blog series on Caterpillar’s experience with Stratasys FDM Technology, we will take a look at how the company’s engineers found a simple yet effective way with 3D printing to solve a production line assembly problem.

When assembling the breather ports of an engine, it has to be done at a precise angular position so that connecting tubes can be lined up when added at a later date.

But even with blueprint specifications, it can often be difficult for assembly technicians to know if the outlets are exactly positioned since it’s determined by eye without a precise physical reference to work from.

This means outlet tubes can be mislocated and an hour of rework per engine would have to be factored in if repositioning is required later on during assembly.

To solve the problem, Caterpillar printed a 3D printed fixture that correctly positions the outlet tubes before they are clamped and bolted down.

The fixture has a circular indicator with built-in degree marks to help verify that the breather port tube is angled properly for alignment with the connecting hardware during assembly later on in production.

This checking fixture is a good example of how helpful 3D printing can be as it can be easily printed in one piece in a short timeframe. The position marks are easily printed onto the fixture during the print operation.


Since adding the fixture into the assembly process, the problem of mispositioned outlet tubes has been eliminated. With the quick deployment of FDM 3D printed tools and manufacturing aids, productivity-killing rework is avoided while quality is improved despite typical daily production levels.

In the next and final post, discover how 3D printing assisted Caterpillar in the validation of a proposal to reduce production cycle time.

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