cnc cut from bottom going up

[laughin4u]

hi, I need help, I am new with vcarve version 12 and I have a AXYZ 4008 cnc. When I design my project, my toolpath shows all the right move and I transfer it to toolpath for AXYZ. I am using a 3/4 inch board. When I start the cnc, it will cut the lower pass first(3/4" from top), then the second one in the middle(1/2" from top) and the final on top of the board(1/4" from top). Can someone tell me what I am doing wrong. Thanks

[Rcnewcomb]

What post processor are you using when you save the toolpaths?

[4DThinker]

Sounds like your Z axis is swapping minus for plus. Did you zero Z on the bed surface or the top of the board? If on the surface is that what you set when you started the project in VCarve? Whatever you told VCarve is what you should do when setting up on the CNC. If all is correct then check the post processor as @Rcnewcomb mentioned.

[adze_cnc]

Last night on the SeaBus I was trying to wrap my brain about how this could happen. I have never, ever, ever, had our machine do that.

First off, though, have you done previous cuts with the machine that were fine?

If the wiring is OK and not flipped as 4D mentions then the only way I could see this happening is:

• VCarve z-zero set to material surface
• 4008 z-zero set to spoilboard
• post processor throws away the minus sign so that Z-0.2500 becomes Z0.2500

A very unlikely combination of events really.

Can you post the failing NC file? You'll probably need to compress it to a ZIP file to post here or if you are unsure you can rename it from filename.nc to filename.txt and post that. Your CRV file would help too.