3DP leadscrew-nut insert boosts accuracy of 3D-printed prototypes

Engineers typically do not have access to 3D printers to do this prototyping. Instead, most of them contract with a third party to get quick turnaround on parts. With the new Haydon Kerk 3DP prototyping services, machine builders can now get help with this type of design verification.

Even in instances in which design engineers do have access to 3D-printing machines, parts produced by such machines are often unsuitable for motion-axis verification. That’s because a major challenge in motion control (particularly leadscrew assemblies in which one surface slides on another) is the materials commonly available for additive manufacturing aren’t designed with tribology that is suitable for power transmission.

Those materials commonly exhibit high friction and poor wear characteristics because they are primarily formulated for mechanical or part-geometry stability. Useful prototyping of a leadscrew-driven axis, however, relies on accurate simulation of the leadscrew-nut assembly’s tribological performance, as this directly impacts power consumption and anticipated life.

The leadscrew-nut inserts have a threaded interior (with a high-efficiency thread form) and a hex-shaped exterior to embed into flanged nut bodies or into more-complex 3D-printed prototype assemblies. In addition to the hex shape, which radially locks the insert into the nut body or assembly, each insert also includes a ring groove that (with adhesive) axially locks it into place.

The 3DP nuts support OEMs that use additive manufacturing for short lead times. These nuts are made of advanced materials that are engineered explicitly for production-part performance. That means the nuts transmit power in a way that’s more representative of how standard volume parts will operate under load, which in turn boosts design-verification accuracy.

Currently, Haydon Kerk offers the 3DP nut inserts in a lubricated polyacetal or a proprietary Kerkite KN30, a self-lubricating, high-performance engineered polymer.

OEMs that ultimately arrive at a successful design iteration after use of 3DP inserts may then source their production leadscrew components from Haydon Kerk in bulk quantities — in forms that include nuts machined from the same composite material as the 3DP offerings or (for higher volumes) custom nut components molded as complete monolithic plastic pieces, with metal features overmolded into the design where needed.