Linear Bearing

[tekno]

Hey... was doing the search looking for rails and came across these rails And so I thought I would ask what you all thought about them

[High Seas]

Seems like a few members have "talked" about them - but I haven't seen any feedback from using them. There are a few that use the 80/20 (including myself) for the frame and supports and it seems like a "natural" to use the slides too. The Bosch and other types have a slide I recall too. There is often some of used gear "about" that may be a little cheaper too.
Maybe I'll have to take the plunge at some point and buy a pair to find out for myself.
Anybody??
Cheers - Jim

[buscht]

I have some of those 80/20 slides for another purpose. They won't work well for a CNC rail.

Too much slop and if you get the slop out, they bind. Aluminum extrusions aren't dimensionally straight enough for the accuracy you need. So you have to keep the bearing surface quite loose to avoid binding.

[tekno]

thanks buscht..

[Carl_Huff]

Geez fellas ....

I used linear slides from Futura (the T-slots people) for a panel saw that I built. I used the 'wide' (3 inches???) versions and they worked great. So great that I was thinking of using them for the CNC wood router that I am planning. Are you sure that they are that bad???

[buscht]

Carl, I would love to be proved wrong about these slides. Let us know how it works out.
Trent

[Carl_Huff]

buscht ,

In my case I used four 3 inch wide bearings where I could have gotten away with two. Could I have inadvertently eased the problem that you describe because I have so much slide surface area in contact with the aluminum extrusion? I didn't go out of my way to 'overtighten' the slides either. In my case I used the the 1.5 by 3 inch extrusion on edge as I was looking to reduce errors due to the 'mid beam' deflection of the extrusion. The extrusion is unsupported over a 4.5 foot distance. Or perhaps the error is there and I just don't see it because I am cutting down 4 by 8 foot panels for cabinetry.

Hmmm ... I hope someone speaks up that has experience using them for CNC applications.