Hi Gollo
The Bezier method of drawing is best explained by the following animation.
http://www.artafterscience.com/docs/bezier_tool.htm
and as a general drawing technique for straight lines and curves in a bit better detail at
http://www.creativepro.com/article/d...-drawing-tools
As far as I am aware and I am not an Autocad user there is a plug in that will give Bezier capability to create beautiful free fowing curves. However there are cheap options including 'DoubleCAD XT', a free AutoCAD LT Work-Alike. More info at the following
http://www10.aeccafe.com/nbc/article...ticleid=650966
Once you have the curves you want for instrument making save them in a format that AutoCad can under stand and reopen them in AutoCad - arrange with any other parts and present them to what ever you are using to convert then to code for driving your high speed wood working router.
I have done a quick search on Google for 'AutoCad Bezier tools' and it looks as if AutoCad is lacking support. If you want beautiful free flowing curves it looks as if you need to think about replacing AutoCad unless there is a workable plug in to give Bezier functionality to AutoCad. Also look at Rhino which I struggle with but is capable of very good curve generation - be warned these programmes are expensive so the free IMSI DoubleCAD XT might be of help. Check that it is really free not a cripled version of an expensive software package!
Hope this helps.
Pat