Acme Screws Drive Linear Motion Innovation

Christopher Nook by Christopher Nook

Acme lead screw assemblies are used to convert rotary motion into linear motion by turning the screw or the nut. One of the most popular types of lead screws uses the Acme thread form which typically has an included thread angle of 29°.

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Acme lead screw assemblies are used to convert rotary motion into linear motion by turning the screw or the nut. One of the most popular types of lead screws uses the Acme thread form which typically has an included thread angle of 29°. This produces strong efficient threads, which has helped to establish them as the best option for many of the motion control applications that we see today. Acme screws are simple and effective and rely on sliding frictionbetween the nut and the screw. Acme lead screws have a much lower replacement cost than other types of screw systems such as ball and planetary screws.

So why are Helix Linear Acme lead screws a big driver of linear motion innovation? It’s all part of their makeup. We use a proprietary custom-blended thermoplastic material integrated with friction fighting PTFE. We can also apply PTFE coating to our screws to further reduce friction. Ball screws and roller or “planetary” screws have their place but are often overkill and overpriced for many applications. A case-in-point example of these benefits and how they are driving innovation is their increased use within medical applications such as a syringe pump.

Affordability

Acme screws are significantly less expensive than complicated roller screws or ball screws, in terms of both initial cost and ongoing maintenance. Acme lead screws have fewer moving parts, which translate into lower cost. When combined with the costs of customization for your particular application, cost savings could be as high as 85 percent when compared to competing screw types. That’s a significant savings and more and more OEMs are starting to reap the benefit. In certain clean applications, Acme lead screws can be run without lubrication. No lubrication to re-apply means no maintenance to worry about and therefore lower maintenance costs.

Reliability

Every engineer knows that more moving parts mean more chances for failure. Helix Acme screws owe their reliability to their simplicity. This simplicity of design also directly translates to quieter operation and less vibration. Lead screws are more tolerant of contaminants than ball screws. Ball screws have complicated ball return tubes and when dirt gets into the balls and raceways they no longer have smooth travel and their life is reduced. Roller or “planetary” screws have expensive gears that must be precisely aligned, all of which greatly increases their cost.

The life of an Acme screw does depend on the application. Many factors such as load, speed, duty cycle, nut material, cleanliness, and screw coating all have an effect on the useful life. Contact Helix Linear Technologies engineering department for assistance with your application. We will use our expertise and experience to optimize your solution.

Customization

Acme screws can be custom manufactured for any application, from microscopes to cutting machines. Helix Linear Technologies manufactures precision Acme screws and trapezoidal screws via thread rolling, thread milling or thread grinding with standard inch diameter sizes that range from 1/8" to 6" and metric diameter sizes that range from 4mm to 65mm. Based on this manufacturing flexibility, designers and engineers can make the screw fit the design rather than having to make the design fit the screw. This is a big driver of innovation because with the hundreds of different configurations available, Acme lead screws can be included in virtually any design envelope without having to sacrifice other design considerations in the product development process. And by the way, our screws are not the only thing that can be customized – many of our standard nuts can also be modified to suit your particular application, or our engineering team can work with you to provide a totally custom solution – thereby providing greater design flexibility.

Affordability, Reliability and Customization

These three characteristics can all be used to describe Helix precision lead screws and they are three primary reasons why Acme screws are instrumental in driving linear motion innovation.

Be sure to download our Precision Lead Screw Quick Reference Guide featuring our newest line of precision lead screws.