Setting XY zero with larger planning bits

I am having trouble figuring out how to set the XY zero when using larger bits like planning. I have tried setting the XY to the center of the bit and it misses a portion of the side and bottom edge I need to plan. I then tried to set XY where the edge of the bit is over the XY point and that did not work. Can some one please enlighten me on how to set this up. Thanks

Hi Randy, X,Y are set based on the center of the bit and if you’re using easel, than the front left corner if the origin would be the default origin where you’d align the center of the bit to.

Are you surfacing a workpiece or the wasteboard?

randy ,

this might help? (166) How to find XYZ - CNCnutz Episode 157 - YouTube

Use a smaller bit with a point if you don’t have a touch plate. If you do have a touch plate then use any smaller bit such as a 1/4 inch end mill. Set your X Y zero location with that bit and t hen change to the bit bit and zero your Z axis with it. Design your tool path with the big bit selected. The XY zero location will be the same regardless what bit you change to. Your design software that generates the tool paths will compensate for the diameter of the bit.

Like Randy said, XY Zero are located at the centerline of the bit or spindle. So when you use a more managable bit to find X Y zero, when you change to your big bit you XY zero hasn’t changed one iota. The Z will be the only thing you need to update.