Japan (日本語)
Japan (日本語)
Caterpillar fixture hero image.

Caterpillar cuts rework time with an FDM check fixture.

aaron pearson
Aaron Pearson May 18, 2021
May 18, 2021

In the first post of our three-part series featuring Caterpillar, we saw how the company’s engineers use FDM Technology to respond quickly to production disruptions. In this post, we’ll see how Caterpillar finds a simple yet effective way to solve a production line assembly problem that causes repetitive rework.

The breather ports on a Caterpillar customer’s engines have to be assembled at a precise angular position so they line up with connecting tubes added at a later assembly stage. However, it’s difficult for assembly technicians to know if the outlets are positioned exactly per blueprint specifications. Angular position is determined by eye and there’s no precise physical reference to work from. As a result, outlet tubes can be mislocated and have to be repositioned later in assembly, adding an hour of rework per engine.


To solve the problem, Caterpillar used a 3D printed fixture that correctly positions the outlet tubes before they are clamped and bolted down. A circular indicator with degree marks is built into the fixture to help the assembler verify the breather port tube is angled properly for alignment with the connecting hardware added later. An advantage of 3D printing this type of check fixture is that it can be easily printed in one piece in a relatively short time with the position marks incorporated during the print operation.
Caterpillar fixture image top.
Caterpillar fixture figure image.

Since adding the fixture into the assembly process, Caterpillar has eliminated mispositioned outlet tubes. Given typical daily production levels, this saves three to five hours of rework each day. It’s a good example of how FDM 3D printed tools and manufacturing aids can be quickly deployed to improve quality and avoid productivity-killing rework.


To see how Caterpillar engineers used 3D printing to help validate a proposal to reduce production cycle time, check out the third installment in our three-part blog series.