Replacement gear from the 3D printer - small change, great effect

What was needed: Replacement gear for a tractor engine

Material: iglidur i3

Manufacturing process: Selective laser sintering

Requirements: High wear resistance, good sliding properties, good mechanical characteristics

Industry: Commercial vehicles

Success through cooperation: 10 times more cost-effective manufacturing costs than with conventional manufacturing processes, complex component manufactured in one piece, improved abrasion resistance

The application at a glance:
The igus cleaning team uses a tractor for its work, e.g. spreading and transport tasks. After some time, the gear that served as a starter for the tractor's engine was so worn that the tractor could no longer start. The manufacturer was unable to provide a replacement and so the tractor remained out of service. After about a year without a tractor, it was to be scrapped. However, the igus 3D printing team came into play shortly beforehand and was able to reproduce the worn and broken gear and print it in just a few hours. The tractor is now running reliably again thanks to the iglidur i3 gear, which has significantly better sliding properties and higher wear resistance than the previously installed gear made of regular plastic.

Getting spare parts from the original manufacturer is often not as easy as you might think. In the case of the tractor used by the igus cleaning team for various tasks, such as gritting the site, the manufacturer was also unable to provide a new gear. The broken gear serves as a starter for the engine's large drive pulley. The load exerted on the gear each time the engine was started was too high for the component made of regular plastic and wear and breakage quickly set in. A special gear was therefore needed that was a perfect fit, wear-resistant and had good sliding properties.

The 3D printing team tackled the problem and was able to produce a drawing of the original based on the broken gear. This was converted into a STEP file and then printed using selective laser sintering with iglidur i3. The costs of tool-free 3D printing were more than 10 times more cost-effective than mechanical production. The special shape of the gear with the lead screw geometry inside is no problem for additive manufacturing. In addition, the printed gear promises a longer service life than the previously used gear. This meant that the tractor could be saved from being scrapped and became fully functional.

At igus, there are various ways to have a gear printed. Design engineers, for example, can use the igus gear configurator to configure the required gears and then order them directly from igus. How exactly this works is explained here. Alternatively, an existing CAD model can be uploaded to the 3D printing service and ordered with the appropriate igus material and manufacturing process.

Various load tests are carried out in the igus test laboratory. All igus products are put through their paces in order to make the online tools reliable and meaningful. One of these tools is the service life calculator for gears, with which the service life of gears made of iglidur i3 or iglidur I8 can be calculated depending on the application-specific load data. This makes it easy to check whether the material is suitable for your own application and when you should change the gear before it fails.