Editing Broach G-code

[BradyCNC]

Title say it all i need to edit this program to run smaller for a different job, the guy who wrote it doesnt work here anymore and nobody here knows how.  Finish sixe for the broach needs to be 3.925-3.930. This is a fix for a competitors part so i need to not screw this up haha i just havent messed with writing broaches before so im at a loss

O0031.NC

[JParis]

I have NO idea what this is even doing...it's a bunch of G81 cycles with no way to relate what it's doing besides punching into a position

[BradyCNC]

yeah basically, like i said my knowledge of this is SO limited, Its a .375 rectangular broach that puts keys into a bore, its one of those programs that "just works" at my shop but now i need to figure out how to alter it to fit a smaller bore and im at a loss

or i need to figure out how to write new code 

 

[JParis]

OK, let m e see how much of this I can explain

G00G55G90X1.245Y-1.245(POSITION TO CENTER & ORIENT SPINDLE)  <-----This is the starting position
M150S3000  <------- I "think" this is the spindle clocking an orientation
(S3000, S2100, S1200, S300)
G43Z0.1H3
M184 <-------another guess this is locking the spindle
G91G99G81X.001Y-.001Z-3.65R-4.5F250.K77  <----This is stepping over in X&Y 77 times at an increment of .001" 
G00G90Z5.
G00G28G91Z0
G90
M185  <-------unlocking the spindle 
M00

Your starting position is what will need to change....whatever the distance is between the depth you currently get and the depth you want to have.

If you're going to go deeper, you'll likely want to increase the K # number repeats

If it'll be shallow, you may be able to reduce the number of repeats....

You'll then have to figure(add/subtract, the K values to make sure the distance achieved by the number of repeats gets you to your desired depth...

[Minkash]

Check this program generator,  Broach Gcode Program Generator - CNC Broach Tools™.

[BradyCNC]

17 minutes ago, JParis said:

OK, let m e see how much of this I can explain

G00G55G90X1.245Y-1.245(POSITION TO CENTER & ORIENT SPINDLE)  <-----This is the starting position
M150S3000  <------- I "think" this is the spindle clocking an orientation
(S3000, S2100, S1200, S300)
G43Z0.1H3
M184 <-------another guess this is locking the spindle
G91G99G81X.001Y-.001Z-3.65R-4.5F250.K77  <----This is stepping over in X&Y 77 times at an increment of .001" 
G00G90Z5.
G00G28G91Z0
G90
M185  <-------unlocking the spindle 
M00

Your starting position is what will need to change....whatever the distance is between the depth you currently get and the depth you want to have.

If you're going to go deeper, you'll likely want to increase the K # number repeats

If it'll be shallow, you may be able to reduce the number of repeats....

You'll then have to figure(add/subtract, the K values to make sure the distance achieved by the number of repeats gets you to your desired depth...

This is EXACTLY what i needed to know and im happy i was right about most of it. With this i can make it. Thanks so much. Wish me luck haha