On Sat, 2009-06-06 at 23:48 -0500, Jon Elson wrote: ... snip > You pretty much need to have a big tombstone fixture around all the > time. Any small parts, vise, etc. are mounted to the back of the > tombstone. Visibility and access to the workpiece are a pain.
Sounds like there could be a down side to the idea. > > To move the knee, I was thinking of a ball screw with the same > > configuration as the present acme screw, except the bevel gear would > be > replaced with a custom disk motor directly mounted to the screw > end. You also need a brake I forgot about the brake, but if the knee is counter balanced, it may not be needed. > and an encoder in there, and it would be a ROYAL pain to work on this > stuff inside the knee! But once it's set up, I'll never need to work on it ever again :) When I did get into the knee to fit a Y axis ball screw, I found a lot of nasty casting burrs. It's like a coral reef in there. My Shizuoka looks almost as nice inside, as out. I'll try to deburr the inside of the BP knee before I work in it again. The inside of the knee also seems to collect a lot of chips. I'm a little surprised the bevel gears can live with a pile of chips on them. > I suggest you drill an oval hole in the side of the knee, put a > toothed belt pulley on the top of the knee screw and mount a motor to > the outside of the knee. Possibly an idler pulley could wrap the belt > around the motor pulley so that both sides of the belt are real close > together when they pass through the side of the knee. > > Jon I suspect that well placed, moderately sized holes would affect the knee strength and stiffness very little. The long belt bothers me. The screw could be rigidly mounted to the knee, then spin the nut and nut support column. You would need column sized bearings at the foot, though. It's hard to justify all the effort on a machine that was never intended to be a CNC. I just got another idea. Fit a worm gear to the screw end. A worm shaft bearing would be mounted to one knee side wall, and a hole just big enough for a motor shaft on the other side. Or a ball screw on each side of the knee, but then there would be twin screw issues, like on some routers. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ OpenSolaris 2009.06 is a cutting edge operating system for enterprises looking to deploy the next generation of Solaris that includes the latest innovations from Sun and the OpenSource community. Download a copy and enjoy capabilities such as Networking, Storage and Virtualization. Go to: http://p.sf.net/sfu/opensolaris-get _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
