On Wed, 2008-04-30 at 23:29 +0300, Alex Joni wrote: > A machine (in my oppinion) would have a home switch (where it would home > consistently). Starting from that position you have software limits (you > are allowed to travel up to the soft limits, and never beyond). > Outside of the soft limits bounds, you have the hardware limits.
Having soft and hard limits seems redundant. Ops, (thought pop) like you say ahead, the soft limits keep you from having to to go through hoops when you trip a hard limit. What is a good term for the bumpers at an axis end. I was thinking soft, for the config file limit, firm for physical limit switches and hard for crashing bits of steel designed to take it. > Usually > these are wired as tripping faults which disable the motor amplifiers, > so crashing them is a serious problem. (One would need to move the axis > by hand back off the limit switch). > On some machines the hardware limits aren't as extreme, and are used > only as a fault input to the controller (emc2 in our case), so if it > trips emc2 errors out. You still have the option to push override limits > then, and jog the axis in the other direction back off the limit switch. > > But yeah, I agree with no home switch (homing by eye) software limits > move according to where you homed. Having limit switches but no home > switch seems like an odd setup to me. I would use one of the limit > switches as the home switch and properly define HOME position and HOME > OFFSET (this scenario is supported by emc2, and described in the docs). > > Regards, > Alex Because home has limited use, I have been forgetting to set it on my mill. With my HNC lathe home/limit is in hardware, so I rarely think about it. I just hit the home button so I can see the pretty cross hairs on the display. Touch off is the biggie. I just realized you need an accurate, consistent home so that you don't need to touch off for every start of EMC2 while running the same part. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC/EMC CNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending Craftsman AA 109 restoration Shizuoka ST-N/EMC CNC) ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
