[Rekd]

Originally posted by Scott_bob ref: Posted by Rekd on 12-09-2003 07:47 PM: -------------------------------------------------------------------------------- Using a .187 dia. Carbide End Mill. How fast can your Fadal mill a slot .250" x 1.000" and hold +/-.001 in 6061-T6 Aluminum say .2 dp? -------------------------------------------------------------------------------- On the Fadals I've run... about 15 IPM, and even then I wouldn't guarantee +-.001 *************************************************** That sounds just about right... On a Fadal the slot width could be held +/-.001 going NO faster than F15. -------------------------------------------------------------------------------- I should have described the end of the slot for this discussion better, it would have R.125 on both ends, so it would be oval, (G03 at both ends)... -------------------------------------------------------------------------------- This Slot length would NOT be +/-.001 Why? Because the Fadal Control is not accurate within +/-.001 in circular interpolation at feeds higher than F40. Not even the New Augusta or 104d... A CNC machine uses what is called the "feedback loop" to control the current position in a move as constantly as it is capable of processing. The CNC with the tightest feedback loop will be the most accurate; the loosest feedback loop will be the least accurate. Let’s face the facts here; we all get what we pay for, right? The low end priced CNC will not be as tight as the high end priced CNC. Would any of the Lower priced CNC users out there disagree with this observation: Accuracy of +/-.001 interpolated circles smaller than .500 in diameter or R.250 Feed NO faster than F15. Accuracy of +/-.001 interpolated circles bigger than 1.000 diameter or R.500 Feed NO faster than F40. Anyone perform Renishaw Ball Bar tests on your CNC to see why? Renishaw identifies and rates the factors as to their affect on circularity… By the way Rekd, what was that “other” contributing factor that you wanted to include in the poll? Scott

You're absolutely right, Scott. To do a circle THAT small with a Fadal would take an act of congress..

Have another look at the poll, in which I have now voted.. (WoW, I tied it up!) My second choice would be the programmed tool path, as it would directly affect the functionality via Feeds.

'Rekd