How do you zero the X0 center with your tool for CNC?

[bebob1]

In tutorials people dont ever talk about it, especially for manual lathing since they eyeball the fact the piece is completely faced off when they set the Z center.

But for CNC, you have to tell the machine where the tool zero is, especially when you change tools around and things get offset every time.

How do you tell the machine where x0 is in terms of where the cutting edge is actually pointing? Is there a way to calibrate this properly. Video tutorials dont normally talk about this. I guess one can face off the ends manually, then turn the outer diameter of the stock, then zero the x on that, then measure actual diameter on micrometer, then offset by the radius to get it to the cutting edge center.?

Is there a proper procedure to doing this?

Otherwise the machine might be cutting parts that are too big or too small with the center not cut or over cut?

Complete lathe noob.

[hoss2006]

That's the procedure I've used and have seen other CNC lathe pros use.
skim the OD, measure, move to zero then zero the axis.
Works very well for accuracy.
Hoss

[bebob1]

cool thanks. ill try that. i was thinking pros might be suggestion dial indicator this and that and minus this from that and tada.

[bebob1]

what about if you need to change tools?

but say you are changing tools with the same post, so its not possible to store tool offset information from a prior to run test. Then what?

You can't take out the part and put a junk part to test, then put the actual part again to run every time you change tools right?

[txcncman]

You need to switch to an indexable tool changing system. But, you probably will not do that. Right? So, with the spindle not turning, touch the tool to a measured diameter with a shim of a measured thickness between the tool and the measured diameter. Then do your calculations and movement to set the X axis tool offset zero value.

[bebob1]

The shim thing isnt fool proof though since the material can be soft and there is deflection of the tool and everything so it might not be true cutting diameter even after calculating offset.

[fretsman]

The shim thing isnt fool proof though since the material can be soft and there is deflection of the tool and everything so it might not be true cutting diameter even after calculating offset.

Over time, you'll get the "feel" of feeler/shim stock and the friction of the material. It just takes some time and "hands-on" to learn it a bit but it will come.

Dave

[txcncman]

The shim thing isnt fool proof though since the material can be soft and there is deflection of the tool and everything so it might not be true cutting diameter even after calculating offset.

Nothing in machining is fool-proof. This is why to be a good, quality machinist takes desire, education, knowledge, training, practice, wisdom, and luck.

Quit complaining and learn the skills needed. Or, switch to an indexable tool changing system as was suggested.

[fragger6662000]

but if you air on the side were you will leave material on you can update toe tool size and re do the final pass. i do this with bearing seats and anything that i need to hold a tolerance on.