On 3/20/2010 2:12 PM, Gene Heskett wrote: > On Saturday 20 March 2010, Paul Keeton wrote: > >> Gene, >> >> Do you (or anyone else) see any any issue with using a separate >> encoder and leaving the tach on the motor alone? I have seen this done on >> other servo systems with great reliability. Normally backlash is not an >> issue unless it is an excessive amount on those systems. You simply don't >> use backlash comp if there is a scale on the machine. You may have to if >> your encoder is on the screw. Almost definitely if your encoder is on the >> motor and you have a gear box. I would have to agree about the lag time. >> What would you suggest? And by the way, I sensed no disrespect, I asked a >> question and you respectfully responded with an intelligent answer, and I >> thank you for that. >> >> Dave >> > I believe there are several here who are using the tach signal back to the > motors controller, and the encoder output then going back to emc, and it > apparently works quite well. But I should let those who are do the > testifying that it works well. > > I can't personally testify to that as my only machine is a thoroughly hacked, > all new Z axis saig x1, with 262 or 425 oz steppers on it, aka the smallest > HF they sell, with bigger tables and the rebuilt z, it does pretty well if I > can keep the damned typos under control. > > It missed the first 0 after the decimal point yesterday and carved a hole in > the side of the barrel channel of a gunstock I first carved by hand 40 some > years ago. So now I have some thin strips of walnut being glued up to make a > plug for it after I squared up the hole, the original blank was about $130 in > 1969. With a little luck, it won't be too noticeable once its fully > refinished. That is basically what I was doing anyway as I'd pulled the Rem > 788 action and its 2nd shot out Shilen 22-250 Barrel and have refitted it for > a heavy SS Howa 1500 in 22-250. > > [...] > > Yikes. That was probably painful to look at after it happened. Sometimes you just can't to the Estop fast enough. :-(
Dave ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
