[mechanicer]

Are there anyone try to make linear ball bearing (like THK, star)?

Maybe from aluminium.. Using the same recirculating ball metod.

[Enraged]

buy the real ones off ebay. the carraiges are easy to come by, and cheap, its the rails that can get expensive as you increase the length.

[Zach_G]

I had been thinking about this myself. I copied a fairly simple design using small precision shafting cradled in a channel as the the track surface with bearings between 4 shafts. To get recirculating action, you'd need to drill a hole through the channel material and fabricate some sort of redirect blocks. Could be done with some scraps of plastic, a dremel and alot of patience plus trial and error. Furthermore, If you sized all the right parts, it could be possible to build a linear guide w/o a mill using the dimensional accuracy of cold rolled steel bars and rectangles to create the channel, however machining colled rolled much causes it to warp due to the internal stresses caused during the forming of colled rolled steel. Otherwise you would need to clean up the somewhat rough dimensions of raw material in a mill. I was personally considering this option until a couple weeks ago when ebay seemed to get flooded with cheap linear rails. I might still take a stab at this approach someday just to prove it can be done. Plus you could effectively tailor the dimensions to your exact needs instead of what can be had second hand on ebay, and it would definitely appeal to the hardcore DIY'er. As far as sources for material, I was looking at www.metalsdepot.com for raw material, and mcmaster or ebay for the bearing balls.