Thomas Powderly wrote: > if there are many index signals during motion, then use a 'near home' > swx to identify which one and home in one direction > the 'near home' switch should reduce the velocity so the index is reliable. > i used a 90 to 1 gearing on a 3R Caxis with a prox switch and dog to > identify which of 90 indexes was the correct index. > the dog was simply a sheet metal flag on the rotating bit, the prox > was in a hole thru the outer casting > keep the index in center of any dog to dog cycle > We are talking about a spindle encoder here, and the special case where the actual spindle is pretty much inaccessible to mount an encoder. I solved this in my 1J Bridgeport head by putting 3 gear-tooth sensors inside the head to effectively turn the bull gear into an encoder disk. Some other Bridgeport heads make even this scheme hard to do. Igor has a way to access a shaft that is at the input to the back gear mechanism, so it is either 1:1 with the spindle or turning at a faster speed but with a fixed ratio. So, the original problem returns, that it would be hard to get a once/rev sensor directly on the spindle. If he was going to go to the trouble of doing that, he might as well put 3 in there and make it an encoder.
Jon ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
