Small installation space, big challenge: gears printed in 3D are the solution

• What was needed: Suitable gear for the extremely small stepper motor of the remote-controlled searchlight
• Manufacturing process: Selective laser sintering (SLS)
• Requirements: Small diameter, long service life, minimal wear
• Material: iglidur® i3
• Industry: Commercial vehicles
• Success through collaboration: Increased competitiveness through the realisation of the new product design, wear resistance requirements were exceeded

Due to the low installation height of the searchlight, small and powerful stepper motors were selected for the drive units. The standard gears on the market did not fit into the available installation space and were therefore not suitable for the stepper motor shafts. In addition, the small installation space requires the gears to have a long service life in order to minimise the necessary maintenance of the parts. Standby GmbH quickly realised that the small gears had to be custom-made. The injection moulding process was initially an option, but was considered inefficient due to the relatively small number of parts required.

With a dimensional accuracy of ± 0.1 mm, the gears were additively manufactured in series from iglidur® i3 powder using the laser sintering process. Furthermore, the iglidur ® i3 material enables maintenance-free operation of the searchlights thanks to the high wear resistance and the self-lubricating specification. All the requirements of Standby GmbH were thus fulfilled by the igus® 3D printing service.

Standby GmbH itself tested the durability of the 3D-printed gear by first subjecting several printed test samples to its own wear test. Mr Klaus Pfiffer, Technical Support at Standby GmbH, explains: "The result was outstanding. Even after many cycles and operating hours, which were far above the maximum product service life specified in advance, the printed gears and pinions showed no wear at all, even those whose partners were not made of iglidur® but of aluminium."

In many sliding applications, small-format components offer mechanical or aesthetic advantages. A creative, fine structural design of a product requires a manufacturing method that fulfils the design requirements precisely and cost-effectively. The additive manufacturing of components through the aligned melting of powder layers characterises the SLS process, which delivers sliding components with a wall thickness of up to 0.7 mm. At igus®, the demand for particularly small wear-resistant parts, such as gears with a tooth modulus of 0.2, is also met. However, a different 3D printing process is suitable for this, namely DLP printing. In this process, synthetic resin is exposed to UV light layer by layer and thus cured.

​igus® has developed suitable high-quality 3D printing materials for the various mechanical applications. For DLP 3D printing, igus® offers the iglidur ® i3000 resin. Its abrasion resistance is 30 - 60 times higher compared to regular synthetic resins. The SLS powder iglidur ® i3 is most frequently processed in the printing service and is characterised by high wear resistance. If machine parts are moved using a worm wheel system, iglidur ® i6 is recommended due to its increased sliding properties. In addition, some application environments require specific material properties, such as food conformity. igus® has also developed 3D printing materials for these and other requirements.