Need Help!- Mach is rounding corners on a Square?

[RedCNC3]

I am using Mach3 with a CandCNC MP3000 torch height control on a plasma cutting machine. The machine has been running fine for several months, but now it will cut inside corners of a perfect square with a radius, and cut the outside square fine. It will only cut square in exact stop mode, but this is not ideal for plasma cutting. I have not be able to adjust the CV settings to fix this problem and it still does not explain why the same program would cut corners differently. On the display screen when scrolling through the code it displays all movements properly, but when it is cutting it displays the movement of the inside square with rounding the corners on the screen? I am stumped to why this is happening, and am losing a lot of time and material every time it happens… some one help, please!

I have attached several pictures of the problem, G-code and the Mach configuration.

[jharvey407]

Originally Posted by RedCNC3 I am using Mach3 with a CandCNC MP3000 torch height control on a plasma cutting machine. The machine has been running fine for several months, but now it will cut inside corners of a perfect square with a radius, and cut the outside square fine. It will only cut square in exact stop mode, but this is not ideal for plasma cutting. I have not be able to adjust the CV settings to fix this problem and it still does not explain why the same program would cut corners differently. On the display screen when scrolling through the code it displays all movements properly, but when it is cutting it displays the movement of the inside square with rounding the corners on the screen? I am stumped to why this is happening, and am losing a lot of time and material every time it happens… some one help, please! I have attached several pictures of the problem, G-code and the Mach configuration.

I'm not a Gcode expert, but I have had this problem myself.

I took a quick look at you TAP file. It look like the inner square is cut in lines N0390 to N0440. I see that some of the moves are G02 commands, which are ARC commands.

I think the problem is your CAM software, not Mach3. It looks like the CAM software is putting ARCs in the corners.

I would take a close look at the settings of your CAM software. Maybe that is where you need to address the CV settings. Or perhaps slowing your feed rate would eliminate the ARCs.

I hope this helps.

[holbieone]

looking at your code the center cut out has 90 degree corners

and the corners of the out side have a .0305 radius

[RedCNC3]

Thank you for the input on this problem, but after looking at the code, I do agree the inner square has no radius on the corners. Although the outer square does have a slight radius, it is nothing like the inner square. The thing I am confused with, is if it is a setting, why would the inner and outer square cut differently on the same program? This problem stumps me :s I was hopping some one had the same problem with mach3 would be able to shed some light on this.

[RedCNC3]

I re-loaded the config from several months ago when it was not having this problem, but the machine still is rounding over the corners on all the files it cuts

[ger21]

Try using the CV angle setting, and set it to 89°, in general config. Make sure CV is turned on.