Why I get Double Cut Lines on McX5?

[kolias]

The attached pictures show an item I cut on 1/2" plywood (about 8” long by 3” wide). The cut finished and I realized that I made a mistake and had the endmill cutting on the inside instead of the of the outside of the perimeter. But I also realized that the cut was done in some places inside and outside. What I do wrong and I get the double cut lines? I only selected the perimeter chains once.

Also one of the pictures shows the end of the g-code lines. When I do my settings I ask for X0 Y0 Z1 so the tool will end at the starting point of the cut. The code finished at X0 Y0 Z1 as I wanted but before the program finished it went far away from the starting point.

Why the code produced lines N1724 and N1728? Can I delete them?

Thanks

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[joeavaerage]

Hi,
what CAM software are you using? Sounds like it is not correctly cutting to the outside of the part?

G91 is incremental mode, and G91 G0 X0 Y0 is very different to G90 G0 X0 Y0.

Craig

[Superman]

The N1724, N1726 lines are return to home position code for a Fanuc controlled machine.
You need to have a post modified, or use one specific to your control.

I assume you are new to Mastercam ?
You need more practice on how & what chains you select to place a toolpath to follow...
Even to what direction you select the chain determines what side the tool is to follow...
If the tool is on both sides, you have selected more than 1 chain ( or parts of a chain).

[kolias]

Thanks for taking the time Craig

I have access to mastercamX5 and have been using it for some time with no problems at all. Not that I’m an expert on it but I manage to do what I want. I think the problem is with this particular piece which it looks like the perimeter is made of several lines joined together and it all depends on how you select the chains. After the chains selection the CAM program selects G90/91 depending if lines are straight or circles

Now I have been able to select the chains properly and it looks good and later or tomorrow I will give it another try.

Thanks Superman for the tips and you are right since as mentioned the problem is how I do select the chains and now looks like I got it right

Nicolas

[kolias]

It looks like the problem now is with Mach3,

When I load the g-code in Mach3, the drawing in the screen is out of proportions and in the wrong quadrant and the g-code line N116 is highlighted. From the past I have a note on Mach3 which says “…if the geometry has a lot of circles/curves change in the General Config the IJ Mode from Inc to Absolute….”

I did that but it’s not enough, something else must be changed because nothing works on Mach3 without fixing the problem. I rebooted Mach3 but the same problem persists, line N116 is highlighted and the motors do not work.

Any ideas or I should ask the Mach3 forum?

[kolias]

Decided and posted my question to the Mach3 forum which seem more appropriate

[adidoro]

I loaded that line of g-code in my controller software and found the explanation.

[kolias]

I loaded that line of g-code in my controller software and found the explanation.

Thank you for your time,

I found the solution last night. The g-code for this cut includes 2 operations, one is the contour to cut the perimeter and the other is a drill operation to drill 4 holes 1/8" diameter each both operations using the same 1/8" endmill. When I deleted the drill operation then the code worked good and I did my cut.

Now I learned for next time not to combine operations. I'm not an experienced cnc user and perhaps there are operations which you can combine but for me I will not do it again.