16mm Pillow block on 5/8 Thomson rails

[lasersafe1]

I have a set of two beautiful 5/8 (.625") Thomson hardened steel rails 3 feet long. They would normally use the SPB10-opn linear bearings, which are quite expensive. I have found 16mm open bearings online which is .629" for significantly less cost. Do you think this would be suitable on a metal cutting CNC mill build? My gut says yes, but I would like to hear from other experts. I can purchase these 16mm in either steel circulating ball bearing or a hard polymer. The polymer is more expensive. I am unsure which is best or if it is even an option.

I already have one metal cutting CNC machine with the proper bearings, but I'm thinking of building another with my extra rails.

Thanks.

Similar Threads:

• Ball screws & linear rails.
• Left hand, Metric Ball screws?
• Sources for new BIG ball screws and rails?
• Is it legal to mix inch and metric ball screws?

[joeavaerage]

Hi,
using 16mm bearings on 5/8 rails will result in lash, a definite no-no in CNC.

Are theses rails round? End mounted round rails are way to flexible for a mill. Square rails bolted every 2-4 inches to an absolutely rigid
bed is required for metal cutting machines.

Craig