Strange lathe issue - only when boring

[dmbgo]

Perhaps I'm doing something wrong, but I seem to have trouble on the lathe mainly when I'm boring a piece of stock.
Here is the procedure that I follow:
1/ Select T1111 in CNC12 Set Z 0 to the Z surface of the item to be bored
2/ Take a trial cut of the job, using the MPG and the boring bar that I intend to use and measure the hole size (say 16.0mm)
3/ Setup the X axis position to match the measured diameter (16.0mm)
4/ Tell CNC12 to take a small extra amount out of the hole in the job (16.5mm) and measure the hole size again (say 16.5mm)
5/ Embark upon a boring operation, using the same tool number (in this case 1111) starting at 16.5mm and ending at 20.0mm, with 0.1mm cuts
6/ Panic and stop job, because the tool is about to cut about 15mm from the X16 position, although the DROs on the screen show that CNC12 thinks the tool is in about the right place (see the second image)

I wonder if somehow CNC12 thinks it is Tool 101 that I'm using now?

[dmbgo]

report_0035FF8A7F34-0730203594_2024-03-22_14-36-57.zip

(844.41 KiB) Downloaded 3 times

Here is the system report that I always forget to post

[PhilipTrueman]

Did you set up tool 11 in the tool offsets page? And set up the Z part zero with tool number 1 and tell part Z zero that you have used tool number 1 to set the part zero to the end of your part then update the WCS.

[dmbgo]

Thanks Phillip,
Here's what I did:
In the past, I had setup tool 11 (12mm boring bar) in the tool table, with X and Z offsets based on the offset from tool 1 (If I move the boring bar in or out of the tool holder, I change the Z offset, after selecting tool 11).
I used the mdi to specify T11 (the display showed T1111), then the cam function to create the job, I specified T11 as the tool in the cam job as well.
While the display was showing T1111 as the selected tool, I set Z0 to the Z surface of the job.
Is there a better way? I don't understand how this would make the X position for the tool change.

[cnckeith]

page 69 shows the id tool measurement process, good to review this
https://www.centroidcnc.com/centroid_di ... manual.pdf

[dmbgo]

I had a quick look at this, thanks Keith, I will review it in more detail today. It will be good to understand what's happening.

[PhilipTrueman]

Thanks Phillip,
Here's what I did:
In the past, I had setup tool 11 (12mm boring bar) in the tool table, with X and Z offsets based on the offset from tool 1 (If I move the boring bar in or out of the tool holder, I change the Z offset, after selecting tool 11).
I used the mdi to specify T11 (the display showed T1111), then the cam function to create the job, I specified T11 as the tool in the cam job as well.
While the display was showing T1111 as the selected tool, I set Z0 to the Z surface of the job.
Is there a better way? I don't understand how this would make the X position for the tool change.

Did you set the part Z zero again with tool 1

[dmbgo]

No, I didn't use tool 1 again that session, only tool 11. In the end, I created a new tool (Tool 8) which had exactly the same offsets etc as tool 11. Then I did a test bore with tool 8, measured the hole diameter, set the x diameter and proceeded to bore the job successfully. I'm still unsure whether the issue is fixed however, without having a root cause of the initial problem.

[cncsnw]

You can set part Z zero using Tool 11.

However, it is not sufficient to just have T11 showing as the active tool number in the status window in the upper right. You must ensure that you have Tool Number 11 on the Part Setup screen, next to "Part position: 0.000", before you press F10/Set.

However, your problem appears to be related to X offsets or part zero setting.

With tool 11 in place and clear of the end of the part, where does it go when you MDI "T1111" then "G0 X0"?

With your tool 1 in place, where does it go when you MDI "T0101" then "G0 X0"?

[dmbgo]

Exactly what I was thinking CNCSW, the Z position remains correct for the tool (now tool 8) but the X position appears to have moved out by approx +15mm. It is still v early in the morning here, but when I finish my breakfast, I will go out to the lathe and replicate the issue, to get a clear answer to your questions. I will also have a look at the tool offsets in the X direction between tool 1 and tool 8, to see if they are coincidentally about 15mm.