[hawkeyeammo]

I'm doing a simple thread milling operation and can't seem to get BobCam to post any Z values in the G02 posting routines.

This is a simple 1.2" deep 1/2-13 thread operation. I don't get it. There should be a Z offset for each of the arc operations. What am I doing wrong.

It even shows the z helical interpolation in the graphic on the screen and in the on screen simulation but the posted G Code has no Z offsets in it so the threadmill goes toward the top of the hole and just spins around there! Pulling hair out! Help.

BobCam settings.

Feature: Mill Thread
Diameter: .50
Top of Feature: 1.2
Total Depth: 1.2

Posting
Arc Moves

Thread Mill
Diameter: 0.3720
Protrusion Length: 1.5

Patterns
Top Down
Inside

Parameters
Right Hand
Thread Diameter: 0.5000
Thread Height: 0.0666
Thread Pitch: 0.0769
Threads Per Revolution: 1
Threads Start Angle: 0
Depth: 1.2000

Leads
Lead-In/Lead-Out
Circular
Radius: 0.0500

Resulting GCode



(Machine Setup - 1 Mill Thread)
(FEATURE MILL HOLE - 0.5000)


N18898 T17
N18899 S5140 M03
N18900 G90 G54 X-2.5938 Y-2.625
N18901 G43 H17 D17 Z2.2 M08
N18902 G00 Z1.4
N18903 Z1.3
N18904 G01 Z1.2 F59.11
N18905 X-2.5798 Y-2.575
N18906 G17 G02 X-2.5298 Y-2.625 I0. J-0.05
N18907 X-2.6578 Y-2.625 I-0.064 J0.
N18908 X-2.5298 Y-2.625 I0.064 J0.
N18909 X-2.6578 Y-2.625 I-0.064 J0.
N18910 X-2.5298 Y-2.625 I0.064 J0.
N18911 X-2.6578 Y-2.625 I-0.064 J0.
N18912 X-2.5298 Y-2.625 I0.064 J0.
N18913 X-2.6578 Y-2.625 I-0.064 J0.
N18914 X-2.5298 Y-2.625 I0.064 J0.
N18915 X-2.6578 Y-2.625 I-0.064 J0.
N18916 X-2.5298 Y-2.625 I0.064 J0.
N18917 X-2.6578 Y-2.625 I-0.064 J0.
N18918 X-2.5298 Y-2.625 I0.064 J0.
N18919 X-2.6578 Y-2.625 I-0.064 J0.
N18920 X-2.5298 Y-2.625 I0.064 J0.
N18921 X-2.6578 Y-2.625 I-0.064 J0.
N18922 X-2.5298 Y-2.625 I0.064 J0.
N18923 X-2.6578 Y-2.625 I-0.064 J0.
N18924 X-2.5298 Y-2.625 I0.064 J0.
N18925 X-2.6578 Y-2.625 I-0.064 J0.
N18926 X-2.5298 Y-2.625 I0.064 J0.
N18927 X-2.6578 Y-2.625 I-0.064 J0.
N18928 X-2.5298 Y-2.625 I0.064 J0.
N18929 X-2.6578 Y-2.625 I-0.064 J0.
N18930 X-2.5298 Y-2.625 I0.064 J0.
N18931 X-2.6578 Y-2.625 I-0.064 J0.
N18932 X-2.5298 Y-2.625 I0.064 J0.
N18933 X-2.6578 Y-2.625 I-0.064 J0.
N18934 X-2.5298 Y-2.625 I0.064 J0.
N18935 X-2.6578 Y-2.625 I-0.064 J0.
N18936 X-2.5298 Y-2.625 I0.064 J0.
N18937 X-2.6444 Y-2.5859 I-0.064 J0.
N18938 X-2.5743 Y-2.5769 I0.0396 J-0.0306
N18939 G01 X-2.5938 Y-2.625
N18940 G00 Z1.4
N20274 Z2.2
N20275 M09
N20276 M05
N20277 G91 G28 Z0.
N20278 G91 G28 X0. Y0.
N20279 M02

[MikeC8]

Under the posting tab, change countour ramping output to line moves, default is arc moves.

[hawkeyeammo]

Yuck! That's not helical interpolation. That's doing it by hand. That's what you do when you have a mill that doesn't support G02 or G03. Is there a bug that keeps bobcad from putting the appropriate Z moves when you use G02 and G03?

[hawkeyeammo]

I think I figured it out guys. There seems to be a bug in the post processor downloaded from Bob Cad's website. I replaced this line...

64. Arc move XY.
n,g_arc_plane,g_arc_move,x_f,y_f,arc_center,feed_r ate

with this line...

64. Arc move XY.
n,g_arc_plane,g_arc_move,x_f,y_f,z_f,arc_center,fe ed_rate

and voila the Z interpolations are there! Hope this helps some other people.

[The Engine Guy]

You are correct, that is the reason

Here is the code I get using the standard BCx3x.MillPst, seems spot on to me


(FIRST MACHINE SETUP - Machine Setup - 1)

N01 G00 X0. Y0.
N02 Z5.
N03 Z1.
N04 G01 Z0.375 F53.821
N05 X5. Y5.
N06 G17 G02 X10. Y0. Z0. I0. J-5.
N07 X-10. Y0. Z-0.75 I-10. J0.
N08 X10. Y0. Z-1.5 I10. J0.
N09 X-10. Y0. Z-2.25 I-10. J0.
N10 X10. Y0. Z-3. I10. J0.
N11 X-10. Y0. Z-3.75 I-10. J0.
N12 X10. Y0. Z-4.5 I10. J0.
N13 X-10. Y0. Z-5.25 I-10. J0.
N14 X10. Y0. Z-6. I10. J0.
N15 X-10. Y0. Z-6.75 I-10. J0.
N16 X10. Y0. Z-7.5 I10. J0.
N17 X-10. Y0. Z-8.25 I-10. J0.
N18 X10. Y0. Z-9. I10. J0.
N31 M05
N32 G91 G28 Z0.
N33 G91 G28 Y0.
N34 G90
N35 T1 M06

(END OF FILE)
N36 M30

(END OF PROGRAM)
%

Regards
Rob
:rainfro: :rainfro::rainfro:

[hawkeyeammo]

Dang Rob, those are some big ass threads.

[The Engine Guy]

Dang Rob, those are some big ass threads.

Errr, not really, it`s a 30mm dia hole with an internal thread of 1.5mm pitch 10mm dia thread mill, pretty normal sort of job for the boys on the shop floor to attack

Not much to "screw" up there if you pardon the pun

We all got "metricised" back in `72 and yes it hurt

Regards
Rob
:rainfro: :rainfro: :rainfro:

[jrmach]

Errr, not really, it`s a 30mm dia hole with an internal thread of 1.5mm pitch 10mm dia thread mill, pretty normal sort of job for the boys on the shop floor to attack

Not much to "screw" up there if you pardon the pun

We all got "metricised" back in `72 and yes it hurt

Regards
Rob
:rainfro: :rainfro: :rainfro:

Metric Suks