On Tue, 2013-02-12 at 13:59 -0600, sam sokolik wrote: > our big machine has 1 limit and 1 home machine for each axis - but a > cam on each end of travel. (so 1 switch is used for both ends of travel)
Nice idea ... why didn't I think of that? ;-) It does take a different arrangement of switches but... I've had a serious runaway when the coupler to the encoder breaks. 600 ipm with a ton or so of bed gets exciting in a hurry. Yes, I know for you big guys ... you say 'only' a ton of bed! I've also experienced runaway when testing a new controller. Never did get it to settle down. I had some control ... G1X0YO G1X29Y15. all went well mostly... for about 5 iterations and then it took off full bore for the upper right corner. E-stop really saved the day. I typically back off of hard limits or a bit more :-( by disconnecting the power leads to the servo motor and using a 12 battery charger to get will inside the limit switch. Peter: I've always assumed that the servo motor would take the power supply down faster than a decent resistor; and has better heat dissipation. I've not tested that but have cooked some fairly high wattage resistors. Of course plugging them with AC would really stop them but required hefty relays. a bit more than a tuppence! Dave > > (actually what I am using for the home switch was actually the tool > change location switches) > > sam > > On 2/12/2013 1:45 PM, Chris Radek wrote: > > On Tue, Feb 12, 2013 at 02:34:20PM -0500, Pete Matos wrote: > >> John, > >> That is about the clearest most logical response I could have asked > >> for. Quite honestly I am unsure if my machine has three switches per axis > >> as you described. I will have to check. It is definitely a PRO CLASS > >> commercial machine as you say but I am unaware of the actual limit design > >> of the original control. Lets assume for a minute tho that it does not > >> have a third switch for homing here. How would you say would be the best > >> limit setup in that case? > > > > Put the limit switches in the estop chain, and make yourself some > > reference marks and use index-only homing if you don't have home > > switches. Or, just add home switches. > > > > My real machine has a "limit override" momentary recessed button > > that routes the estop chain around the limit switches. If it's > > sitting on a limit you can hold it in, and come out of estop and jog > > carefully off the switch with the wheel. I feel pretty good about > > the setup, and it's mostly pre-retrofit wiring - that was the > > original control's scheme. > > > > ------------------------------------------------------------------------------ > > Free Next-Gen Firewall Hardware Offer > > Buy your Sophos next-gen firewall before the end March 2013 > > and get the hardware for free! Learn more. > > http://p.sf.net/sfu/sophos-d2d-feb > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > ------------------------------------------------------------------------------ > Free Next-Gen Firewall Hardware Offer > Buy your Sophos next-gen firewall before the end March 2013 > and get the hardware for free! Learn more. > http://p.sf.net/sfu/sophos-d2d-feb > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
