Scout Emblem - Router Cutting Into Piece Immediately

[davew215]

Hi All,

I would like to cut a profile of the scout emblem, but I can't figure out an issue that I'm having.
When I run my gcode, the router immediately plunges into the piece about 0.01" and then moves to the correct position to start (image attached).
I have my coordinate system at the bottom left of the piece, and I zero the mill at this coordinate system before starting. I then raise the mill about 3mm and turn on the router.
I am using SolidWorks with a HSMWorks add in. I believe that the retract height is set correctly (image attached), and the router appears to follow the simulation (attached) once it is in the right position. The job is set to work from the bottom left coordinate system.
When powered down, everything feels like it moves smoothly.

Below is how the gcode starts off. If anyone has advice, please let me know. It would be greatly appreciated, as I am stumped right now!!!

%

(scout emblem 1-21)

(T2 D=0.125 CR=0 - ZMIN=-0.8461 - flat end mill)

G90 G94

G17

G20

G28 G91 Z0

G90



(2D Pocket1)

M9

T2 M6

S8000 M3

G54

M9

G0 X4.763 Y10.3524

Z0.64

Z0.2794

G1 Z0.1525 F24

G3 X4.7635 Y10.3531 Z0.1478 I-0.0451 J0.0387

X4.7652 Y10.3551 Z0.1438 I-0.0457 J0.038

X4.7674 Y10.3583 Z0.1411 I-0.0473 J0.0359

X4.7698 Y10.3623 Z0.14 I-0.0495 J0.0327

X4.6659 Y10.4198 Z0.1335 I-0.0519 J0.0288

X4.7698 Y10.3623 Z0.127 I0.0519 J-0.0288

X4.6659 Y10.4198 Z0.1205 I-0.0519 J0.0288

X4.7698 Y10.3623 Z0.1139 I0.0519 J-0.0288

X4.6659 Y10.4198 Z0.1074 I-0.0519 J0.0288

X4.7698 Y10.3623 Z0.1009 I0.0519 J-0.0288

X4.6659 Y10.4198 Z0.0944 I-0.0519 J0.0288

X4.7698 Y10.3623 Z0.0879 I0.0519 J-0.0288

X4.6659 Y10.4198 Z0.0814 I-0.0519 J0.0288

[aforww]

I'm real shaky at reading code but I think the issue is that Z0 before the G90. I had the exact same problem with a version of UGS I was having. It was dropping Z then traversing to x/y zero when I would issue return to zero command.

[aforww]

Also, anytime you save your gcode file, change the G54 to G0 Z10. That will move the Zaxis up before milling just in case.

[Derek the Admin]

It is the G28 that is getting you. I usually suppress that in the post processor options. You can set it to a desired position with G28.1 though. As Aforww said I often like to delete the G54 because sometimes I'm in a different coordinate system (G56 for instance) depending on where I am working from.

Here is an outstanding writeup over on the Inventables forum that will each you all about G28:
discuss.inventables.com/t/learning-about-g28/12205

Good luck.

[aforww]

Jan 22, 2017 2:17:25 GMT Derek the Admin said:

It is the G28 that is getting you. I usually suppress that in the post processor options. You can set it to a desired position with G28.1 though. As Aforww said I often like to delete the G54 because sometimes I'm in a different coordinate system (G56 for instance) depending on where I am working from.

Here is an outstanding writeup over on the Inventables forum that will each you all about G28:
discuss.inventables.com/t/learning-about-g28/12205

Good luck.

Glad you provided the correct answer lol.

[davew215]

Thanks for both of your help! That inventables page and video were very informative.

I was just test practicing on scrap MDF, but now I feel comfortable to tackle it again with some pretty wood.

Thanks again!

--Dave

Attachments:

[mikedpp]

Dave, Just out of curiosity, how long did it take to cut that emblem in MDF? Thanks, Mike

[davew215]

Hi Mike, it took me 30 minutes using a 1/8" flat endmill. It probably could be faster, but after the MDF I switched to a hard wood. I'm also new to all of this, and I've been leaning on the side of caution. Attached is what I ended up with after routing the edges, sanding, and staining.

Attachments:

[mikedpp]

Dave, I don't think 30 minutes is bad to go all the way through the material. Thanks for the info. Mike