Does anyone know of a source for ground ball screws at good prices?
I contacted Hiwin and they really don't carry off the shelf ground ball screws mostly rolled. The off the shelf type screw is for bridgeports which could work...thay said about $500 for 32" and under with nut.
Companies like Hiwin grind their screws on very expensive Mitsui Seiki grinders, specifically designed for manufacturing ballscrews. It's a slow process, so they only grind as much thread as needed (specified by the customer). Sometimes a customer may need a 45" shaft but only 30" of threads, and thus save money by paying for the equivalent of a 30" ballscrew. Plus, most customers of ground screws want to purchase them ready to install with very accurately ground bearing journals in place.
It wouldn't be cost effective to grind long sections and chop them up as they do with rolled screws. There's just too much wasted thread from the cutoffs and the bearing journals. In addition, long sections of thread require long travel grinders, which are few in number and much more expensive.
Automation4less.com sells NSK ballscrews in various diameters, pitches, and lengths. They might have what you want. Accuracy is C5, 0.0005" max lead error per 300mm. A lot of them are probably good enough to pass for C3, 0.00027" max lead error (detailed inspection reports are provided with each screw), but are still only rated for C5, since I don't think they offer C3 screws as off-the-shelf products.
I apoligize for resurrecting an ancient thread.
Ground screws are not too difficult to come by. We stock thousands of ther ourselves over here at WInter Engineering.
Any questions, pm me.