Cast iron is cheap (in quantity), and it wears well. Good features for machine tool applications.
----- Original Message ----- From: "Jon Elson" <el...@pico-systems.com> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Friday, August 20, 2010 22:39 Subject: Re: [Emc-users] 4th Axis. > Speaker To-Dirt wrote: >> >> >>> Cast Iron is easy to machine, but a bit messy, black dust >>> flying all >>> over. I don't understand your reference to Al and >>> gear cutting loads. >>> >> >> I meant I would not trust the structure of the 4th stage being made >> from Al. Al creeps, thus never really returns to it's orig shape when >> placed under load. If I have to make my own 4th stage, I'm deciding which >> material to use. I can get steel, but I was told to avoid steel as a >> machine tool body because it's easy to establish acoustic standing waves >> in that material while iron damps them out. Which was the reason I >> understood machine tools are made from iron. >> > Small steel structures are usually fine. No question that large machine > structures should be made of cast iron, as it does provide a good bit of > damping. Heavy structures won't vibrate much under reasonable loads. > You can calculate the deflection of a particular structure with fairly > simple formulas. Cast Iron also creeps under load, but generally that > is a VERY slow process, and it takes years to measure the effect. > Probably the larger effect is simple thermal expansion, aluminum is > about 6 X greater than steel. > > Jon > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by > > Make an app they can't live without > Enter the BlackBerry Developer Challenge > http://p.sf.net/sfu/RIM-dev2dev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
