Help with G-code, offset 2d adaptive hole on fusion 360.

_______________________________________________________














LOGIN below to POST your questions and comments on AjaxCNC products.

Moderator: cnckeith

Post Reply
DanielCA92563
Posts: 10
Joined: Fri Oct 13, 2017 1:23 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
System Serial Number: none

Help with G-code, offset 2d adaptive hole on fusion 360.

Post by DanielCA92563 » Sat Dec 09, 2017 5:46 pm

Hi all,
I was wondering if anyone had this problem or could help- I drilled a hole with a 5/16" drill bit (fusion 360), then 2D adaptive to counterbore it with 3/16" end-mill. The drilled hole was supposed to be centered in the counterbore as is seen in the pic of the Fusion360 simulation. But when I actually run the Gcode with the centroid post processor the drilled hole is not centered in the counterbore (2d adaptive on fusion 360). See pic.

I don't think I'm loosing steps in my open loop G0704 stepper CNC as when I rehome, all values are as expected and I even turned down the speeds and acceleration in all axis's but still no change. I've attached, the GCode, was wondering if someone with more knowledge than me can help. Thank you!

edit: oops, this should probably should have gone under CNC acorn board, not sure how to move.

second addendum:
Heres a video of hole the counterbore is not centered on previously drilled hole
https://youtu.be/ht1iUWc0cxg
Attachments
offset adaptive.JPG
IMG_2728.JPG
fusion capture.PNG
1001.txt
the gcode
(29.05 KiB) Downloaded 12 times

diycncscott
Posts: 660
Joined: Thu Mar 04, 2010 4:03 pm

Re: Help with G-code, offset 2d adaptive hole on fusion 360.

Post by diycncscott » Sun Dec 10, 2017 11:05 am

When I plot the Gcode, it plots them off center as well. Do you have a dimensional print? Or at the very least, can you tell us what the center * dia are supposed to be?


There are some bizarre things going on in this post.

1. There are NO arcs. Everything is broken down to tiny line segments (facets). It's no problem for us it's just a really poor way of doing things. The whole program would probably be about 50 lines long instead of 6000+.

2. All tool changes are posted with back to back, conflicting tool number calls. ie..

N30 T15 M6
N35 T14

?????

I removed the 2nd tool number in each case but it didn't help.

Either way, I don't trust this post. I'll guarantee that if you program this in Intercon it will come out perfect.

DanielCA92563
Posts: 10
Joined: Fri Oct 13, 2017 1:23 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
System Serial Number: none

Re: Help with G-code, offset 2d adaptive hole on fusion 360.

Post by DanielCA92563 » Sun Dec 10, 2017 10:58 pm

You should not have guaranteed :) I programmed it in intercon and it looks the same. Picture attached (top is with fusion 360 post and bottom is with intercon). intercon Gcode attached. I've also attached a drawing of the test drilled hole with counterbore (circular pocket) and measurements.

The tool changes was a setting in fusion360 post that allows to "preload" the next tool or in my case with manual tool changes it just gives me a heads up as to which tool is next. it doesn't seem to change the function of the gcode but I disabled it now.

I'm not sure what's going on??

When I load the fusion 360 post and/or the intercon post the drilled hole appears centered in the circular pocket when I graph it in CNC12 but in both cases that's not what happens when I mill it.

For both the fusion 360 and intercon posts, after completing the program I manually ran the 5/16" drill bit down the center coordinate (in my case x =0.350 ) to see if it still entered the originally drilled holed and it did perfectly , see video:
https://youtu.be/4PoseBJxzwk
making me again think that i'm not loosing steps.

And you were right, intercon completed task in about 50 gcode lines vs 6000 lines for fusion360

Any help is appreciated and thank you.
Attachments
cb test intercon.txt
Intercon G-code
(1.82 KiB) Downloaded 9 times
IMG_2738.JPG
top fusion360 botton intercon, neither drill centered.
drawing.JPG

cncsnw
Posts: 354
Joined: Wed Mar 24, 2010 5:48 pm

Re: Help with G-code, offset 2d adaptive hole on fusion 360.

Post by cncsnw » Mon Dec 11, 2017 1:15 am

Is this a bed-type mill?

If so, maybe the spindle head is out of tram (so that the spindle centerline is not parallel with Z movement). If the head is rotated left or right, for example, then there will be an X axis mismatch between long tools and short tools (e.g. between drills and end mills). If the head is leaning out or in, then there will be a Y axis mismatch.

Put an indicator in a mag base on the table. Put a piece of drill rod in a chuck in the spindle. Zero the indicator against the side or front of the drill rod. See what happens with the indicator reading as you jog Z down and up.

diycncscott
Posts: 660
Joined: Thu Mar 04, 2010 4:03 pm

Re: Help with G-code, offset 2d adaptive hole on fusion 360.

Post by diycncscott » Mon Dec 11, 2017 5:38 am

As I suspected, the difference between the 2 programs is that the Intercon generated program plots perfectly while the 360 program plots off center. Load both programs and hit backplot. You will see what I'm referring to.

Regardless of any other issues, the g code (and geometry) being generated by 360 is incorrect.

You should always use backplot to verify your program. 3rd party programs only show you an approximation. The backplot in our software is actually showing you the vectors the control is generating from the g code and sending to the motors.

cncsnw
Posts: 354
Joined: Wed Mar 24, 2010 5:48 pm

Re: Help with G-code, offset 2d adaptive hole on fusion 360.

Post by cncsnw » Mon Dec 11, 2017 2:13 pm

... the 360 program plots off center. Load both programs and hit backplot. You will see what I'm referring to.


I don't see that, at least using CNC11 v3.16. Maybe CNC12 for Acorn is different.

Judging center can be deceptive because of the spiral path.

Use F3/Set Range to plot just lines 1000 onward, and also look at the CNC file with F6/Edit. In the final circuit, the rightmost point is X+0.9351 (line 1058); leftmost point is X+0.5109 (line 1191); top is Y-0.4000 (line 1124); and bottom is Y-0.8240 (line 1259). That gives a center point of X+0.723 Y-0.612, which is the location of the two drilling operations at the top of the program.

I still think his head is out of tram.

DanielCA92563
Posts: 10
Joined: Fri Oct 13, 2017 1:23 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
System Serial Number: none

Re: Help with G-code, offset 2d adaptive hole on fusion 360.

Post by DanielCA92563 » Mon Dec 11, 2017 4:41 pm

Thank you both! You guys are great.
It is almost certainly the column out of tram. I had a small crash a few weeks ago and I remember thinking about how I did not us a torque wrench when I installed the column on my cnc conversion and maybe not tightening the column bolts as much as I should have.
I also discovered new backlash in my Y-axis, so I think I'm going to taker 'er apart then re-tram everything.
Thanks again,
Daniel

Addendum:
12/12/17: I ran a dial indicator down a square on the table, I didn't think this much tilt on the column was possible without it looking like the leaning tower of Pisa. A reminder to me to periodically check nod/tilt/'lash ect. Thanks again.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest