Replacing precision ground ball screws on legacy equipment is complicated by the dissolving of original manufacturers and by product customizations. Offering multiple types of ball screw return designs provides the flexibility needed to keep older equipment running. The long life of machine tool equipment has resulted in machine tools which are often older than their […]
Ball + lead + roller screws
Ballscrew repair from Dynatect: New calculator to decide when to buy (or refurbish)
Alternatives to the increasing lead time for precision ground ballscrews (PGBS) are driving plant managers to reevaluate procurement options. OEMs often choose to only purchase new precision ground ballscrews (PGBSs) without evaluating repair options. Other choose to maintain no-stock or low-stock of PGBS due to ease of procurement. But now with lead times of 16 to 20 weeks, […]
Lead screw selection: What should I consider besides diameter and lead?
Once you’ve gone through the process of sizing a lead screw, you know what diameter and lead will provide the required load capacity, speed, and back driving torque for the application. But there are hundreds — maybe thousands — of lead screw designs on the market. Beyond the basics of diameter and lead, how do you […]
Lead screw sizing in 4 steps
Lead screw sizing is a bit of a hybrid exercise, with similarities to the process of ball screw sizing, but incorporating some of the considerations that come with sizing a plain bearing. While many factors are involved in the selection of a specific lead screw assembly, lead screw sizing — choosing the right diameter and […]
PV Equation: How to calculate the PV value for a lead screw application
Lead screws rely on sliding friction between the nut and the screw to convert rotary motion into axial (thrust) force to move a load. Most lead screw designs use either a carbon steel screw with a bronze nut, or a stainless steel screw with a plastic nut. In either case, there are no recirculating balls […]
Motion Trends: 3D printing aides lead screw design, prototyping
A number of trends in the motion industry are impacting lead screw design and implementation. One of these is the miniaturization of components. For instance, applications in optics as well as medical devices demand high precision, and smaller miniature lead screws can meet high precision specifications and can fit where space is limited and where […]
Motion Trends: Better performing, more customized ball screws
Slow but steady improvements continue with ball screw technology. For instance, developments in manufacturing and materials have improved ball screw performance so that the most recent generation of ball screws have greater load densities than before, leading to high load capacities in smaller packages. A trend that continues is the adoption of ball screws into […]
Is oil suitable for ball screw lubrication?
The short answer is yes: ball screws can be lubricated with either grease or oil. Grease is more commonly used for ball screw lubrication because it doesn’t entail complicated delivery methods, and it requires less frequent re-lubrication intervals. But despite the simplicity of using grease, in many applications, oil lubrication is the better choice for […]
How to improve ball screw rigidity (with support-bearing selection and more)
Updated May 2019 || Ball screw rigidity depends not only on the screw shaft and ball nut, but also on the thrust bearings and on the ball nut and bearing housings. Where: Rtot = Rigidity of the screw system (N/μm) RS = Rigidity of the screw shaft (N/μm) RN = Rigidity of the ball nut (N/μm) RB […]
What makes miniature ball screws unique?
Ball screws are used in a wide variety of applications, but some of the most challenging are those on the extreme ends of the performance spectrum – from large diameter, large lead screws for machine tools, to screws with small diameters and very fine leads for optical and medical applications. For very small, high-precision movements, […]