Rough and finish pass origins cha

[Edsamour]

I am new in the forum, but have a problem and maybe someone can help me. I use a 48” x 48” CNC form Avid cnc. I purchased a 3D model from Etsy to create a carved mirror frame. I set the project up in vcrave pro 10. The preview of the tool paths shows perfect machining of both toolpaths. I use Mach3 to connect to my cnc and use a zero z and corner finding plate. I ran my rough pass with a 1/4” en mill, then I used a 1/8” bullnose tool bit and of course adjusted zero and point of origin with the correct size tool. But the finish pass started displaced and ruin my project. Has anyone had the same problem? I can send the vcarve file if that would help me identify my problem. Thanks in advance for your help.

Ed

[TReischl]

Nope, never had that problem. Sounds like the XY zero did not get set to the proper position. I do not use a corner finding thingy but I would surmise that at some point you have to tell it what diameter the tool actually is? Maybe you did not do that.

[Edsamour]

Thanks for the reply. The difference in the origin was considerable I would say at least 1/2 inch. The tool it I used for rough pass was a 1/4” end mill and finish pass I used a 1/8” bullnose.
Well, I will try again with a cheaper material, I ruined the mahogany frame I had prepared.
Thanks again

[TReischl]

Hold it! Just occurred to me, you should NOT be resetting your XY zero at all when changing tools. Just the Z.

[martin54]

Like Ted I have never had any problems, how are you setting your zero position? I know you said you used a touch plate & corner finder BUT are you setting an X Y Z zero position for each Bit?? Seemed to me from your post that you were but I could be wrong

Only set your X Y zero position for the first bit (roughing pass) When you do your tool change use the same X Y zero & just set your new Z Zero position.

If the file is copyright then you can't share on the forum

[Edsamour]

Thanks for the replies. Yes I have reset the xy when I change bits, I thought I had to because the bits are different size rough pass with 1/4 and finish pass with 1/8.
Thanks again, I will try again resetting only z with a smaller job.