What was needed: replacement gear for a tractor motor
Production method: selective laser sintering
Requirements: high wear resistance, good sliding and mechanical properties
Material: iglidur I3
Industry: utility vehicles
Success for the customer: manufacturing costs ten times lower than with conventional production methods, complex part made in one piece, improved abrasion resistance
The application at a glance:
The igus cleaning team uses a tractor for their work, e.g. for gritting and transport. The gear serving as a starter for the tractor's motor was so worn out after a while that the tractor could no longer start. The manufacturer was unable to provide a replacement, so the tractor remained out of service. After about six months without a tractor, it was to be scrapped. However, shortly beforehand the 3D printing team came into play and was able to trace the worn and broken gear and print it within a matter of hours. The tractor now works reliably again thanks to the gear made of iglidur I3, which has significantly better sliding properties and a higher wear resistance than the previously installed gear made of conventional plastic.
Often, it is not as easy as one thinks to obtain replacement parts from the original manufacturer. This was the case here: the manufacturer of the tractor, which the igus cleaning team used for various jobs, such as gritting the site, was unable to provide a new gear. The broken gear operated as starter for the large drive pulley of the motor. The load acting on the gear every time the engine was started was too high for the component made of regular plastic, so that it soon wore out and broke. Therefore, a special gear was required that fitted exactly, was wear-resistant and had good sliding properties.
The 3D printing team tackled the problem and was able to design a drawing of the original gear by using the broken one. This was converted into a STEP file and then printed via selective laser sintering with iglidur I3. The tool-free 3D printing cost €28 per piece, which was ten times more cost-effective than mechanical production, which would have amounted to more than €300. For additive manufacturing, the special shape of the gear with the spindle geometry in its interior is no problem. Furthermore, the printed gear promises a longer service life compared to the previously used gear due to the higher abrasion resistance of the material. The tractor was saved from scrapping and could be used again in its full functionality.
One of the great advantages of 3D printing is the virtually unlimited freedom when designing the required parts. There is hardly any shape that cannot be produced in one go. If you want to produce a replacement part that either cannot be delivered any more by the manufacturer or has a special design, 3D printing is the right choice. Often, only small amounts of replacement parts are required. In this case, it is also a lot more cost-effective to produce the parts with an additive method. The tool-free and resource-saving production results in more cost-effective quantities. In the case of the tractor, only one gear was required. With mechanical manufacturing, this would have cost more then €300 - printed in 3D, the piece cost €28.
igus offers different options for printing a gear. For example, design engineers can configure the required gears with the igus gear configurator and then order them from igus directly. How exactly that works, is explained here. Alternatively, an existing CAD model can be uploaded in the 3D printing service and commissioned with the suitable igus material and manufacturing method.
In the igus test laboratory, different load tests are carried out. All igus products are put to the acid test to make sure online tools are reliable and informative. One of these tools is the gear service life calculator, which determines the service life of gears made of iglidur I3 or iglidur I8, depending on 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.