The entire premise in the use of a ball screw assembly is to convert motion of one kind, typically rotational movement, into a linear motion. While it could be done with a standard type of screw and nut, the friction factor would dramatically impact the conversion of energy.
The Importance of Precision
With the use of a precision ball screw, friction in the movement of the ball nut up and down the ball screw is minimal. Using small balls that run in the threads and rotate through the ball nut on a continual basis keeps the ball nut off the threads and reduces friction. This is only accomplished when the entire system is manufactured with precision and quality control throughout the process.
In technical terms, the use of the word “precision” in the name of the ball screw indicates that the screws have been made with a tolerance of 5 microns or less. However, this is virtually impossible to detect without specific equipment for measurement, so often the quality issue with a precision ball screw is only demonstrated with how well it stands up under load.
Starting With Quality Steel
It should always be a priority for the manufacturer to choose the best possible raw material from which to machine the precision ball screw. Poor quality steel will reduce the cost, but it will also reduce the life cycle of the ball screw as well.
Other processes, including CNC machining, heat treatment and the use of the latest in equipment and technology to complete the manufacturing process will also be critical.
Manufacturing Expertise
Companies that have been in business for decades have a solid track record of production ballscrews, ballnuts, and full assemblies. It is going to be the best option to work with these types of manufacturers rather than trying to use a startup company or a general machining service, even if they offer CNC services.
Not all companies make custom assemblies as well or offer the option to reverse engineer an existing ballscrew assembly. Be sure to ask questions and find out as much as you can about the company before trusting them with your custom production needs.
