When Do you Enter Lathe Geometry Offsets?

[John3]

When do most people enter tool geometry offsets and what are the pro's and con's of doing so?

Sometimes I've loaded them via the program with the G10 command. Other times I have the setup person enter them. Both ways have their advantages and disadvantages.

What does everybody else do?

John

[Geof]

Originally Posted by John3 When do most people enter tool geometry offsets and what are the pro's and con's of doing so? Sometimes I've loaded them via the program with the G10 command. Other times I have the setup person enter them. Both ways have their advantages and disadvantages. What does everybody else do? John

Can you expand on the advantages/disadvantages? In my shop the tool geometry offsets are always entered by touching off the tool to the workpiece.

[John3]

Originally Posted by Geof Can you expand on the advantages/disadvantages? In my shop the tool geometry offsets are always entered by touching off the tool to the workpiece.

We also initially find the Geometry offsets by touching off the tool to the work piece. Its what we do with those numbers that varies.

We run the the same jobs on the same machine about once every six months. With that in mind, we save tool lists so we can use the same holders and tooling each time. Only the inserts change.

If the holders and tooling are the same, the geometry offsets will be the same, so we just program that into the header of the program using G10 on our Fanuc Controls.

The advantages;

1. We only have the find the geometry offsets once.

2, Its quicker to come up to speed making parts, only tweeks are needed and those are done with the wear offsets.

3. No chance of crashing something because an offset typo during entry, or subtle problems from the wrong tool nose radius values.

4. Less likely an operator can screw with the geometry offsets.

The disadvantages;

1. The programmer must get the offset values and enter them into the program before the program can be used.

2. Occasional simple tool substitutions require a program change and not just offset page changes.

3. The wear offsets don't reflect real "wear" they are have tweek amounts added to them of about 100 mills for tool holder length variations etc.

-John

[Geof]

Okay, we do more or less the same, I did wonder if you were using some form of justified tooling that was preset off the machine so when a tool was installed the offsets for it were entered.

Many of our programs do have work offsets entered by G10; these are when we are machining multiple parts off a length of bar. The first part is done with G54 then the next uses G55 which moves Z negative by the length of the piece plus the parting tool thickness plus a parting allowance.

[M-man]

We uses quicksetter sensor, touch off tool and geometry goes in to offset reg.. Can also be used during Cycle start to check tool...(automatic tool offset)..