Incorrect machine movement

[So not a Guru]

Our head-head Onsrud router, with a Fanuc 31i B5 control, is retracting incorrectly when drilling in 3+2.

When running this code:

N5(RELOCATION HOLES IN PANEL)
G00 G91 G28 Z0.
G00 G91 G28 A0. C0.
G17 G20 G40 G49
G64 G69 G80 G90 G94
M06 T39 (1/4 DRILL)
G56 G17 G90
G90 G43 H39
G00 A-18.435 C0. X3.75 Y18.3259 Z15.0829 M03 S3500
G49
G68.2 X0. Y0. Z0. I180. J18.435 K0.
G53.1
G43 H39
G94
G98 G81 Z15.2689 R17.104 F50.
X-43.25
G80
G49
G69
M05
G00 G91 G28 Z0. A0.
G00 G91 G28 A0. C0.
G90
M30

the head is withdrawing from the drilled holes at angle that, essentially, creates slots!

@cncappsjames

Could there be a Fanuc parameter that is incorrect causing this? Since getting the new post a year or so ago, we have always had trouble getting our holes to be in the exactly correct position, but we've only been drilling 3+2 holes in sheetmetal parts, so we hadn't noticed that this was happening. Today we needed to drill a 1/2" thick panel and things have taken a bad turn.

I also am wondering if this could have to do with the pivot distance in the post being incorrect.

[cncappsjames]

Yeah. This is parameter related. There isn't just one unfortunately. I'm working on a project at a customer this weekend but I'll see if I can put a few things together to check tomorrow. 

[crazy^millman]

On 3/9/2022 at 10:25 AM, So not a Guru said:

Our head-head Onsrud router, with a Fanuc 31i B5 control, is retracting incorrectly when drilling in 3+2.

When running this code:

N5(RELOCATION HOLES IN PANEL)
G00 G91 G28 Z0.
G00 G91 G28 A0. C0.
G17 G20 G40 G49
G64 G69 G80 G90 G94
M06 T39 (1/4 DRILL)
G56 G17 G90
G90 G43 H39
G00 A-18.435 C0. X3.75 Y18.3259 Z15.0829 M03 S3500
G49
G68.2 X0. Y0. Z0. I180. J18.435 K0.
G53.1
G43 H39
G94
G98 G81 Z15.2689 R17.104 F50.
X-43.25
G80
G49
G69
M05
G00 G91 G28 Z0. A0.
G00 G91 G28 A0. C0.
G90
M30

the head is withdrawing from the drilled holes at angle that, essentially, creates slots!

@cncappsjames

Could there be a Fanuc parameter that is incorrect causing this? Since getting the new post a year or so ago, we have always had trouble getting our holes to be in the exactly correct position, but we've only been drilling 3+2 holes in sheetmetal parts, so we hadn't noticed that this was happening. Today we needed to drill a 1/2" thick panel and things have taken a bad turn.

I also am wondering if this could have to do with the pivot distance in the post being incorrect.

There shouldn't be a pivot distance in the post. You are using G68.2 and G43.4 and from Mastercam there is normal output. We chased this down on Head-Table 5 Axis about 4 years ago and once Fanuc helped the builder dial in the correct parameters life was good again. You can use the best way to get around the issue for now is to not use any drilling that is rapiding the drill out of the hole use a G85 cycle. I would try the long code process by disabling the canned drilling in the MCD. If you are getting G0 in the long hand code then it needs to be changed to all Feed Moves. Will not be able to tap, but I wouldn't be tapping on that machine anyway. We had a customer that made a part that past FAI, but in the prove out they never ran the Rapid above 5%. When they started running the Rapid at 100% they broke some drills and holes started getting egg shaped. Tried to pin it back on bad programming, but I knew better. Took 3 months of back and forth and almost a lawsuit before we got it sorted out.