THK HSR30 Rails

[pbunnstf]

I just received a nice looking set of 680 MM THK HSR30 rails and slides (4) that I bought on EBAY. I have never seen or used these before and am trying to determine their condition.

When I move the slides, they run fairly smooth but there is sometimes a small bind felt as they slide. This is when there is no pressure at all on the slide - when they are slighlty loaded with hand pressure, the slide is smooth.

Can anyone tell me if this is normal or do I have a problem?

[mxtras]

Brand new bearings have almost a notchy feel when simply pushed. When loaded, they typically smooth out.

If these are used, they cold have been subjected to just about anything. Is the bind felt shortly after changing direction or is it in the same spot everytime? If it's noticable at direction change, this is normal - it's the balls changing direction in the recirculation channels. If the bind is in the same spot each time or has a noticable pattern, it could be mechanical damage caused by impact.

I think in this case, you have to evaluate the cleanliness and determine whether the bind could be contamination also. Flush them out (if they are used) with a mild solvent - possibly pull the seals (be careful) and see whats behind them. Then purge with light oil while moving them to see if lubrication changes the feel.

Scott

[pbunnstf]

Scott,

Thanks for the info. It is at the direction change when they feel bumpy. If you press down with just a little presure, they are smooth. They look like new condition.