On Friday 25 September 2015 08:07:55 andy pugh wrote: > On 25 September 2015 at 05:35, Gene Heskett <ghesk...@wdtv.com> wrote: > > This means I have to pre-position it above the switch or it runs the > > wrong direction looking for it. > > > > Is there some way to make that initial search direction automatic? > > You can make the search velocity negative to search upwards. > You would need to make the switch actuator longer to stop it searching > upwards if it was already above the switch. > (ie, you can tell it which way to search, but it can't know that it is > already bast the switch) Teeny roller tiped microswitches. The pointer/cam that actuates it can roll right on by with no damage to the switch. I had installed the pointer, then the switch but due to the lay of the casting at the top of the post, I was forced to put the switch at about 45mm's below the top of the post. Mechanically, the nut holder shank for the ball nut hits the top of the slot when the sled is still about 2mm down from flush with the post top.
So, to get the pointer in a position where the limits would keep it from ever going on by the switch, I'd need to move the pointer down on the edge of the sled by 40+ mm's. I should make a new pointer with a wider base and slots so I could adjust it I guess, drilling and tapping 2 new holes in the sled. My switches are all on one wire, so the homing is sequential, Z first for obvious reasons. What I was hoping for, without hacking up some hal memory, was that motion was aware of a switch closing and opening if it went by them in normal programmed motions, and was recording which direction the machine was moving the last time the switches opened. That could then be consulted when the home all command was issued, to determine which side of the switch it was on, and that to find it, it needed to move toward it, then once found, the normal 2nd & slower phase of fine tuning the home would then be resumed. All that would take is the sign of the motion, which could then be used to diddle the sign of the HOME_SEARCH_VELOCITY. Not impossible IF the HOME_SEARCH_VELOCITY's were routed to motion by way of the hal engine. Or even by the interpreter, which can invert the sign of a #<var> by the -#<var> syntax. I may do some "motion" detective work. I see output signals aplenty, but not all the inputs seem to be listed. I was TBT, hoping I didn't have to re-invent the wheel. Sometimes mine don't roll so well until well past version 0.5. :( In the meantime, I'll go see about moving the pointer. Thanks Andy. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
