> > I have extensively used a (non-EMC) machine that requires a rehome > after estop. In at least one case I can remember, I had a crazy setup > that was in the way of homing. If I had estopped during that job, it > would have been a very big pain, involving cranking the knee down > out of the way and losing my origin. > > Even when it is possible to rehome, it is an unwelcome distraction. > The result was that it made me think twice or three times before > hitting estop. I went for feed hold instead - a much harder little > button to hit on this machine -- and it doesn't stop the spindle. > > So I recommend that you fix your machine so the encoders don't ever > lose power. It is such a luxury on my EMC machines to not worry about > hitting estop. On both my servo EMC machines the encoders are run by > the PC power supply so no matter what, if EMC stays running, the > encoders do too. > > Now that I have written this, I notice you don't say it's a servo > system. If you disable stepper amps, I guess you don't have much > choice but to rehome... If this is your situation, I'll say this > is just food for thought (for others) and you should ignore me :-) > > Chris >
Hi Chris, In general, I agree with you on the fact that re homing a machine after e-stop is quite annoying. I had to deal with that on a sharp machining center and found it to be a pain. Most of what I do is one-off work, and I also find the process to be distracting. That being said, I think it's a matter of context. In the context to of me, a person who can claim at least a little proficiency in the subject, doing one off stuff, I don't want to enable that feature. However, in a different context, the one which drove the request, the machine is in use by essentially an operator, that has only basic knowledge of dealing with such machines, and in that case, were looking for predictability, determinism and consistency far more then anything else. In the context that it's being used, I's suspect that they will only encounter this case a couple times a year, as they will be running the same set of tested programs many times over. You are correct, we are running in open-loop on this version of the machine, and as a policy we remove power from most components of the system in an e-stop state (independent of software), which is why we risk loosing position in an e-stop scenario. We are planning on adding encoders to close the loop, but that will be a bit later on... Anyway, my main comment is that it depends on context, and in my opinion it's a valuable feature... Best Regards, -Dave ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
