On Thu, Dec 30, 2010 at 11:27 AM, Jon Elson <el...@pico-systems.com> wrote:
> 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. It would appear that the index count is only necessary if I want to re-tap an existing hole, so I do not really care too much for it. If I have the exact ratio of back gear, I would be just fine using the gearchange component, it appears. I am working on 4th axis right now, but once I am done, I will work on the back gear. 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
