[Fraser23]

HI all,

If I wanted to add a standard OD turning tool in my CNC lathe without a presetter how would I go about setting the 'Z' value, if I don't know where all other tools have been offset against?

For the 'X' I know what the best way is to take a light cut into some stock and measure the diameter then put the value into the 'X' geometry offset.

For example: 1.00" diameter on fanuc controls would be entered as 'X 1.0 measure' in the tool geometry offset page.

But for the 'Z' wouldn't I need to make sure that my Z0 is set to the same point as all all other tools?

Hopefully I've made sense!

Thanks in advance

[the_gentlegiant]

Couldn't be easier. Take any other tool and MDI. Say T2 for instance Make sure you have nothing in whatever Work Offset (like G54) is active.


T0202 (TOOL ALREADY MEASURED)

G0Z0.

Keep your finger on the feed hold and keep your eye on the Distance To Go display to make sure you don't crash into anything.

When the tool stops, that's your previously known Z0.

Now slide a piece of bar stock up to the tool and close the chuck. You now have a Z to set other tools to.

[Fraser23]

Couldn't be easier. Take any other tool and MDI. Say T2 for instance Make sure you have nothing in whatever Work Offset (like G54) is active.


T0202 (TOOL ALREADY MEASURED)

G0Z0.

Keep your finger on the feed hold and keep your eye on the Distance To Go display to make sure you don't crash into anything.

When the tool stops, that's your previously known Z0.

Now slide a piece of bar stock up to the tool and close the chuck. You now have a Z to set other tools to.

Thanks for the reply, that makes perfect sense.

So we go actually use G54 for all of our work on our machines, so I would have to clear this before doing the steps you have mentioned?

Cheers

[the_gentlegiant]

I think most people would measure their tools without the addition of anything in a work offset. It's very common on lathes and mills to have X0Y0Z0 in G54 if the tools were measured at the true location of the workpiece. Look at it this way. If you measure everything with the part sticking out of the chuck the proper distance, what could you possibly need to shift from there? Hence G54 would be all zeros.

I would see where your test tool goes with everything zeroed in G54. It would be best if your tools are all measured at a known or reasonable distance from the face of the chuck. If G54 is all zeros and your test tool wants to crash into the chuck before it finds Z0, then I would say to re-measure all your tools so when the machine is operated in a natural state, meaning nothing in the Active Work Offset, (G54 in your case) the tools are operating in a safe and usable area of the machine tool Work Envelope. I mean why would anyone want Z0 of any tool to be buried say 2" into the chuck? I'm betting your tools are not measured there as it wouldn't make sense.

It sort of sounds like you're wanting to use a Master sort of system. Always measuring newly input tools to a known and repeatable reference point. Nothing wrong with that. Then the only thing you'll need to do is to insert the Z Offset amount that represents the difference in distance from where the tools are measured and where the current Z0 of your new workpiece is located. As it's very unlikely that the two places would be the same. The X offset is generally going to stay at 0 for all jobs because the X will always represent the center-line of the Spindle. That never changes.

[Fraser23]

I think most people would measure their tools without the addition of anything in a work offset. It's very common on lathes and mills to have X0Y0Z0 in G54 if the tools were measured at the true location of the workpiece. Look at it this way. If you measure everything with the part sticking out of the chuck the proper distance, what could you possibly need to shift from there? Hence G54 would be all zeros.

I would see where your test tool goes with everything zeroed in G54. It would be best if your tools are all measured at a known or reasonable distance from the face of the chuck. If G54 is all zeros and your test tool wants to crash into the chuck before it finds Z0, then I would say to re-measure all your tools so when the machine is operated in a natural state, meaning nothing in the Active Work Offset, (G54 in your case) the tools are operating in a safe and usable area of the machine tool Work Envelope. I mean why would anyone want Z0 of any tool to be buried say 2" into the chuck? I'm betting your tools are not measured there as it wouldn't make sense.

It sort of sounds like you're wanting to use a Master sort of system. Always measuring newly input tools to a known and repeatable reference point. Nothing wrong with that. Then the only thing you'll need to do is to insert the Z Offset amount that represents the difference in distance from where the tools are measured and where the current Z0 of your new workpiece is located. As it's very unlikely that the two places would be the same. The X offset is generally going to stay at 0 for all jobs because the X will always represent the center-line of the Spindle. That never changes.

You are correct that we use a "master tool"...this is normally is a finishing tool and is normally T03 position in the turret. We use this to set our G54 each time we change jobs.

If I wanted to change this "master tool" would the same principles apply?... use any other known-measured tool to find Z0 with G54 clear, then simply move my new T03 to the same position?

Thanks again for the replies!

[the_gentlegiant]

If I'm following you correctly, that sounds about right.