On Fri, 2008-06-13 at 13:17 -0500, Jon Elson wrote: > Ian W. Wright wrote: > > > One of the main reasons I want to try to generate gears and, > > particularly, pinions is the great problem I have in trying to make > > working pinion cutters small enough for the watches I work on. > It just seems to me that if you have a CNC machine of any type, > you should be able to cut a master tool for the form required. > Then, that tool could cut the gear teeth directly, and reduce a > 5 hour job to 15 minutes! Even if you only have a mill, you can > mount a disc on the spindle and a lathe-type tool in the vise, > and make a gear cutter by laboriously following the tooth profile. > Then, you could cut radial slots to form the cutting teeth, > harden it, and you'd have a pretty professional gear cutter for > any tooth profile you need. > > Jon
A full gear tooth profile cutter is only accurate for the particular involute gear you are cutting. If you change any parameter, you have a different profile. It's worse with cycloidal gears because the mating profile is different, even when all parameters match (or so I have read so far). The problem is that gear cutting seems to be like house painting, 80% of the work is in preparing the surface and the rest is painting, and preping one house doesn't make the next one any easier. It would be nice to have a system where it takes 10 or 20% of the project effort to make the tool, or 50%, and have a tool left over to use on the next project. The more I think about using face mill inserts and a CNC four axis surface grinder, the more I think you could have it both ways. It would be almost as easy to make a full tooth form cutter as it would be for a semi-generic cutter. It seems to depend on where you prefer to develop the g-code. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC/EMC CNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending Craftsman AA 109 restoration Shizuoka ST-N/EMC CNC) ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
