Thanks for all your comments ..Some very good points to consider ..Prices ..Weight ..Limitation ..accuracy..availability of tooling and probably many more that i havent mentioned
Heres that link to how its explained..Open / closed
http://www.kanabco.com/vms/cnc_contr...ontrol_03.html
There is also some of this topic on CNC zone ..From what ive found so far is that The closed loop is preffered and more accurate up to a point ..Depending on backlash ..If your machine is quite sloppy the work has a tendency to get pulled into the work .
Most hobby mills were made with the open loop on account of afordablity . earlier closed loops were very expensive ..Now with the prices going down Sheline /Taig /and Maxnc offer the turn key models with Closed loop at very affordable prices
http://www.sherline.com/8540pg.htm
http://www.maxnc.net/product_p/maxnc15.htm
http://www.microproto.com/MMDSLS.htm
http://www.taigtools.com/cmill.html
Heres another good link with a used buy and sell section and a good forum
http://www.cnczone.com/forums/classi...cat.php?cat=14
Question for you hobby machinest...How much of your X - Y - Z travel do you use when making the most of your hobby parts ..Do you find you have not enough with your make and model