Where is the retract height measured from?

[anotherpieceofwood (Ryan Suchy)]

Hi,

I am designing a tray with an engraving on the bottom. The file has the zero height set from the top of the workpiece, and the retract height is currently set at .20". My pocket tool path is set to cut to a depth of .60", and my advanced v-carve is set to start at a depth of .60". There are a couple of the rapids that cross the walls of the tray, and I’m concerned that if the retract height isn’t set properly the bit could plow through the tray wall.

My question is in order to avoid crashing through the side of the tray, do I need to set the retract height to .20", as is, or if I need to set the retract height from the bottom of the tray (0.60"). I would just hate to ruin my progress with the carve so far.

Thanks in advance!

[Ed.E (Ed)]

I believe retract height height is above workpiece zero. In you case it would be .200 above where you set Z zero. Check your gcode with NCViewer just to be sure.

[WillAdams (William Adams (Carbide 3D))]

Retract height should be measured from the (calculated) top of stock.

So, if using 1" thick stock, and a 1" retract height, the retract height will be 2" above the surface.