The Hurco KM3P has a setup somewhat like Igor's. In the KM3P (P denotes programmable spindle speed) there is a small 3ph motor with a worm gear which drives the shaft where the crank handle would be on your average BP type mill.
There is a Voltac card which reads a single prox switch which counts the back gear teeth - much like Jon E.'s home built integrated encoder to determine actual speed (but not direction). The Voltac card outputs to two separate contactor units which drive the speed adjustment motor fwd or rev. The Hurco software tests spindle speed after an Sxxxx change or tool change and it is surprisingly accurate for a control originally based on a 8086/8087 dual bus system. (I have the Max32 upgraded boards with the awesome power of Intel 80386/80387 processors!) Mine will set the no load RPM to within +/- 7rpm but usually the error is under 2rpm. This tach setup allows the machine to near rigid tap. The tension/compression holders I have only have about .050" range of movement. The fact that the KM3P uses such a strange control scheme was one reason I have not considered changing to EMC2 for that machine. If I got my hands on a regular KM3 I would definitely to the "upgrade" to EMC2 because it allows easy expansion for adding a 4th axis. Greg in CO ------------------------------------------------------------------------------ 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
