Z-Axis interpolation is slow

Hi All,

I have a gantry router system that is capable of feeds of 60" and rapids of 200", My problem occurs when I am machining a 3D piece at say 40"/min and a Z move is require the whole process slows to a crawl about 2"/min and when back on XY only it ramps back up to 40" It doing 3D interpolation at this point and it slows down. Any thoughts?

Thanks

Keith

How did you make your config?
Please post your HAL INI file

Also do you use the g64 option ?