Friday 28th October 2016

Ground Ball Screw accuracy, rolled screw pricing

The low friction within ball screw designs means that a high mechanical efficiency is delivered compared to that of lead screw designs. A typical ball screw may be 90 percent efficient, versus 30 percent efficiency of a lead screw of equal size. Ball screw specification is often a result of an applications requirement to have smooth, accurate and repeatable linear movement.

A recent application for ABSSAC specified a precision ball screw within an electronic microscope that placed a precision guillotine against test pharmaceutical materials. Extremely fine slithers of test material are then cut off the material in rapid succession for microscopic investigation. A small variance in the sliced materials overall thickness would have had a detrimental effect on the accuracy of the microscopes results. The application demanded a high degree of repeatable accuracy and a precision ball screw could also satisfy the other design prerequisites for it to be compact and cost effective.

By using precision ground ball nuts and then pairing them with precision cold rolled ball screw threads, Abssac could provide a ball screw with lead accuracies of less than 52 microns of error for 300mm of linear travel.  By utilising both ground nuts and rolled screws formats enabled large cost savings, when compared against a completely ground ball screw equivalent.

ABSSAC has many years of experience in supplying precision ball screws. Typically, precision ball screws with outside diameters in the range from 1.8mm to 20mm with a range of leads per diameter can be supplied. Abssac’s ball screw customers often request that the journal ends of the screws are supplied pre-machined, so that the parts are ready to fit. This eliminates potential scrap rates for the customer but also ensures that the assemblies are supplied and certified to the accuracy tolerances required.

Offering one of the most comprehensive ranges of ball screws in the UK, Abssac’s miniature ball screws utilise precision ground ball nuts, running on either precision rolled screws or ground screw stock depending on the repeatable accuracy required.  All our precision ball screws are assembled and inspected in a temperature controlled factory that ensures fit tolerance control prior to delivery. Combine this attention to detail ABSSAC can supply the screws ready to fit into your application complete with end journal machining as a guaranteed finished product. Available in steel or stainless steel as standard, a high efficiency cumulative lead error of C7 can be achieved on the rolled product, and depending on thread length and diameter C0 for the ground stock.

Mr. Phil Jones at Abssac Limited says, “The precision miniature ball screw ranges we supply are ideally suited to optical devices or miniaturised positioning equipment. As manufacturing designs get smaller and demand for more accuracy increases, we can now offer a way of supplying what the designer has previously not been able to obtain.”

To talk to a knowledgeable sales engineer please call 01386 421005

More information on our range of Ball screws can be found here


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