beginer problem:how to make him cut outsidethe line?

[xaco]

hello every1,total beginer here,can some 1 help me and give me a hint how to make my cnc to cut object or shape to exact measures i want..let me explain this begginers problem...i have drawn exact square in corel...10x10 inches..but my my cnc that uses mach3 and lazy cam cuts exactli on center of outline so i get smailler surface of square..i ask this cos of more complicated tasks in 3d... how can i make my cnc cut "to the line" from outside or insisde or outside of 3d object? and 2. cuestion...i want to cut in layers...total depth is 0.5 inches and i want to cut it in 5 passes ,each 0.1 inch...how can i set that after 1. pass of 0.1 i dont have to start cycle again? thanx!!!

[Andre' B]

I am not sure about Mach and Lazy Cam but every CNC I have used has some form of cutter compensation, activated by G41 to the left of the programmed path, G42 to the right of the programmed path, and G40 to turn it off.

Your CAM program should have some way of adding these codes to the G code program it produces.
There are usually many options somthing like.

Computer: The offset is done in the CAM (the G code is the centerline of the end mill but offset from the part by the size of the end mill you tell the cam you are going to use) and does not use the above G codes.

Wear: The offset is done in the CAM like above but the G41,42 are put into the program and if the endmill you use is not exatly the size to told the cam you were going to use you put the difference into the machine controls tool offset table.

Edge: The cam programs the edge of the part and puts the G41,42 comands in the G code and you put the full size of the end mill into the machine controls tool offset table.

[ger21]

Offset your square in Corel by the tool radius. I think LazyCAM Pro can do the offset, but not the free version.

[tigran]

Lazy CAM PRO really can take into account tool diameter, but as said Ger 21 you easilly can do it in Corel Draw. I think it is the same for 3D drawings because you have to cut horizontal layers on one depth then on other depth. Im not sure that I'veunderstood the last question, but when you are using cut/per pass 0,1 inches Mach cuts the small figure for example in 5 cycles.. It begins from one point for same Z, then second time starts in the same point with other Z,,, If you don't like how it works you can each curve convert to small circles wich are overlaying and with same cut per/ pass order mach will drill the circles. Еach circle MAch will drill in 5 passes, at one point it will go to the depth 0,5 inches like punching machine... But this is not rational way!!!!

[Switcher]

Did you try the offsets in LazyCam?

In LazyCam you have to create a tool before you can change any offsets.

I don't think offsetting the drawing is very practical, it might be ok for a simple/single shape. If you get into multiple shapes in the same dxf, it's going to get messy.

[crob09]

Did you try the offsets in LazyCam?

In LazyCam you have to create a tool before you can change any offsets.

I don't think offsetting the drawing is very practical, it might be ok for a simple/single shape. If you get into multiple shapes in the same dxf, it's going to get messy.

Hi Switcher I stumbled across this thread after a search, this suggestion really helped me, it's a good feeling to move forward with a problem and actually see results. Thanks for the screen shot.

Anyway I'm having a bit of trouble posting to Mach3 now, when I try to a message shows in the text area stating the post had taken place but nothing loads to Mach3.

Any suggestions?

Thanks in advance, and thanks for getting me and others this far.

Rob