Tapping Feeds

[Fully_Defined]

This is a refresh of an earlier discussion.

I am using a stock Mitsubishi Meldas post processor, with the exception that I have changed the number of tool length and radius offsets from 99 to 200. It is otherwise the same stock post-processor that you also have installed in your computer.

I am getting weird results with tap feeds. It's becoming clear that the post processor is picking up the feed from the lead-in feedrate in the tool library, which itself is not available to edit when adding a tap.

It is basically a punch instead of a tap.

Here is a sample code, tapping one hole:

O99001 (PART 5)
(T158 D=8. CR=0. - ZMIN=-12. - RIGHT HAND TAP)
N10 G90 G94 G17
N15 G21
N20 G28 G91 Z0.
N25 G90
(DRILL15 2)
N30 M09
N35 T158 M06
N40 S200 M03
N45 G54
N50 M08
N60 G00 X18.375 Y-13.745
N65 G43 Z30. H158
N75 G00 Z20.
N80 G98 G84 X18.375 Y-13.745 Z-12. R18. P0 F250.
N85 G80
N90 Z30.
N100 M09
N105 G28 G91 Z0.
N110 G28 X0. Y0.
N115 M30
%

Can anyone make any sense of this? If I'm wrong to believe that the feed is driven incorrectly, then what can I do to correct this?

[Fully_Defined]

To add, I just read the following thread:

https://forums.autodesk.com/t5/hsm-post-processor-forum/mitsubishi-m700-tapping-post-problems/td-p/8...

And I did the same to the Meldas Post:

I replaced

feedOutput.format(F)

with

"F" + xyzFormat.format(tool.getThreadPitch())

But now instead of getting  a huge feed, I am getting a tiny one:

O99006 (PART 5)
(T158 D=8. CR=0. - ZMIN=-12. - RIGHT HAND TAP)
N10 G90 G94 G17
N15 G21
N20 G28 G91 Z0.
N25 G90
(DRILL15 2)
N30 M09
N35 T158 M06
N40 S200 M03
N45 G54
N50 M08
N60 G00 X18.375 Y-13.745
N65 G43 Z30. H158
N75 G00 Z20.
N80 G98 G84 X18.375 Y-13.745 Z-12. R18. P0 F0.125
N85 G80
N90 Z30.
N100 M09
N105 G28 G91 Z0.
N110 G28 X0. Y0.
N115 M30
%

This is an M8x1.25 tap.

Any ideas?

[Fully_Defined]

Changing to 100 RPM, I get the same feed as 200 RPM:

O99006 (PART 5)
(T158 D=8. CR=0. - ZMIN=-12. - RIGHT HAND TAP)
N10 G90 G94 G17
N15 G21
N20 G28 G91 Z0.
N25 G90
(DRILL15 2)
N30 M09
N35 T158 M06
N40 S100 M03
N45 G54
N50 M08
N60 G00 X18.375 Y-13.745
N65 G43 Z30. H158
N75 G00 Z20.
N80 G98 G84 X18.375 Y-13.745 Z-12. R18. P0 F0.125
N85 G80
N90 Z30.
N100 M09
N105 G28 G91 Z0.
N110 G28 X0. Y0.
N115 M30
%

So that's confusing.

[mark]

Let me know you you need some help on this..our company, NexGenCAM does this as a service for customers.  Prices are very economical and our developers are second to none for posts.  Mark Fischer 262-416-7994 or mark@nexgencam.com

[Fully_Defined · Accepted solution]

Success. I had to extensively edit the post processor, and I just taught myself script.

I did not edit this code (it's straight out of Fusion):

O99026 (PART 5)
(T158 D=8. CR=0. - ZMIN=-32. - RIGHT HAND TAP)
N10 G90 G94 G17
N15 G21
N20 G28 G91 Z0.
N25 G90
(DRILL15 2)
N30 M09
N35 T158 M06
N40 S200 M03
N45 G54
N50 M08
N60 G00 X18.375 Y-13.745
N65 G43 Z30. H158
N75 G00 Z20.
N80 G98 G84 G95 X18.375 Y-13.745 Z-32. R18. P0 F1.25
N85 G80 G94
N90 Z30.
N100 M09
N105 G28 G91 Z0.
N110 G28 X0. Y0.
N115 M30
%