I liked the form tool example you recently did, it was rather informative on how to make the paramaters available useful in a way that wasnt initially apparent. I don't do alot of surfacing, so i've always been rather conservative when it comes around. Its somewhat difficult to define such an operation in the traditional way, effective diameter changes throughout the cut, as do depth and width of cut.. Any chance I could get you to do something similar, as I figure its right up your alley anyway? I'm curious how you arrive at optimal parameters on an operation where the cutting conditions change considerably throughout the toolpath. Thanks regardless, Rob Lockwood