Oh, and one more thing: the "index" signal on the encoder, does not mean a full turn in back gear. It means -1/8 of a turn. Will that be a problem?
On Wed, Dec 29, 2010 at 10:54 AM, Igor Chudov <[email protected]> wrote: > I have a Bridgeport Interact 2 CNC mill and it has a back gear. > > In back gear, the spindle turns at the -1/8 of the original speed, that is, > 8 times slower and in the opposite direction. > > I have an encoder on the driven pulley of the variable drive. Therefore, > when my mill is in straight gear, the angular position of the encoder is > exactly the same as the position of the tool in the spindle. > > However, in back gear the position of the tool in spindle, is MINUS 1/8 of > the position of the encoder. > > I would like to put a microswitch near the back gear lever, so that EMC2 > would sense whether the mill is in back gear. > > The motor runs off of a VFD, controlled by EMC2 (PPMC by Jon). > > If this back gear sensor microswitch is ON, I would like EMC to change its > behavior thus: > > 1) Spindle forward actually tells the VFD to rotate the motor backwards, so > that the actual spindle would spin clockwise, as intended. > Spindle reverse actually tells the VFD to rotate the motor forward, so > that the actual spindle would spin counterclockwise, as intended. > 2) Spindle position (spindle-pos) would be -1/8 of the output of the > encoder ppmc.0.encoder.03.position. > > My question is, what EMC elements I can use to accomplish these two > changes. Cases 1 and 2 seem to be somewhat different, but I think that > someone did this already. > > The hope that I have is that with this microswitch back gear sensor, the > machine would behave very nicely, going forward correctly when forward is > commanded, and able to rigid tap due to proper conversion of driven pulley > position into the spindle tool position. > > Any ideas (how to accomplish items 1 and 2 in EMC) will be most gratefully > received. > > One seems to be some sort of an "if" conditional to choose what output to > manipulate. Another seems to be an if conditional to choose a spindle-pos > multiplier, choosing between 1.0 and -0.125 depending on microswitch input. > > Thanks > > i > ------------------------------------------------------------------------------ Learn how Oracle Real Application Clusters (RAC) One Node allows customers to consolidate database storage, standardize their database environment, and, should the need arise, upgrade to a full multi-node Oracle RAC database without downtime or disruption http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
