dial or test indicator for squaring/leveling linear rails?

[margni74]

I'm looking for indicators on ebay for my diy cnc machine setup.

What is going to be more useful for leveling rails? a test or dial indicator on the end of an arm attached to a magnetic base?

[dertsap]

both have their benefits , i would suggest a dial indicator , youll have more travel to play with

[crazythunder]

Depends on how accurate you need to be. Test indicators are usually smaller graduations where as Dial are not a fine and usually not jeweled where a test indicator will be.

[ViperTX]

Well you have 2 problems....can you accurately move the dial indicator from one end of the rail to the other? You would be better off using a machinist level to level the rail and use a dial indicator at the end of a 3/8" drill rod to set the rail to rail distance at both ends of the rail. You can also use the machinist level resting on some accurate round stock to set one rail to the height of the rail that has been leveled. Do you see the picture?