Using linear rails

[nicko17]

Has anyone made a cnc with linear rails.

Mainly looking to see if anyone made one strong enough to mill steels.

[will gilmore]

many many builds in the forum with linear rails

[nicko17]

I was looking at the linear rails like these



I know there are different style. Are these rigid enough , even when using 2 rails + 4 blocks per axis.

I'm worried they are going to have alot of slop in them.

[RICHARD ZASTROW]

That style was used in the past by many builders. They are usable for light duty machines, but not very good for heavier more accurate machines.

The more demanding machines use ball or roller profiled linear guide ways and matching bearing blocks.

Dick Z

[nicko17]

Alright thanks.

What do most ppl use for support under them. I know you need to have a ground flat surface if you want accuracy. But since i dont have access to a surface grinder big enough , nor do i think 95% of us do. What would be another option ... milling ... some kind of flat stock.

[RICHARD ZASTROW]

Depending on accuracy required, you could mill flat surfaces to mount the rails to.

This can also provide a small shoulder to locate a rail against as most manufacturers suggest. Just keep the shoulder low enough to clear the underside of the linear bearing block.

Dick Z

[will gilmore]

How about finding a surplus steel or granite surface plate? Probably flat enough and a bunch of mass to boot.

[nicko17]

Originally Posted by will gilmore How about finding a surplus steel or granite surface plate? Probably flat enough and a bunch of mass to boot.

That would be almost perfect (cant exactly drill holes in it to mount) I think only option would be epoxy stuff i was hearing about.

[will gilmore]

or through drill and bolt

[nicko17]

What about all those aluminum rails i see people using. I cant seem to find the exact name of them.

[will gilmore]

80/20® Inc. - The Industrial Erector Set�

[RICHARD ZASTROW]

In post #1 you wanted to mill steel. I would not use "erector set" aluminum construction for milling steel unless you are performing "ultra-light" machining.

Dick Z