> That motor can produce rated torque down to near zero > speed. But, a belt reduction INCREASES torque as you lower > spindle speed. In some cases like heavy fly cutting, face > mills, boring, and drilling with large diameter drills, you > need that extra torque. When I put my Bridgeport in the > lowest speed range, > the torque is increased by a factor of 22! > > Jon That's true. Since I was wanting to also go up to 6000 for small cutter aluminium there's no reason to not keep the spindle pulled and a motor pulley and do away with the intermediate pulley. I haven't looked yet but it's quite possible the spindle pulley has the internal splines for driving the spindle. Wouldn't surprise me.
On my South Bend Heavy 10L I have a 1HP 3phase with an Automation Direct GS1 VFD. I still switch belts and use the VFD in the mid range area. But flipping the belts to different speeds on the SB is much easier than it is on the mill. So I'd like a much better dynamic range with one motor. John ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
