Re: [Emc-users] Soft/hard limits & homing (was: Re: emc2.3.0beta2)
On 29 Mar 2009 at 9:43, Rob Jansen wrote: > > All I want is to simply tell it where X0 Y0 Z0 are in relation to > mill > > stock, > Don't confuse limit and home switches. Limit switches prevent damage > to > the machine (but should never be hit in real life). > Home switches determine where your machine's zero location is. I "trip" my Z limit switch every time I turn my mill on. The I set my Z. I don't have home switches on my mill. I guess the use of home and limit switches varies with the design of the machine and the intended use. John -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Soft/hard limits & homing (was: Re: emc2.3.0beta2)
On Sun, 29 Mar 2009 09:43:48 +0200, you wrote: >Steve Blackmore wrote: >> Softlimits? I don't use them. I have limit switches, I don't use them >> either, I think since the eighties I've hit them twice. They are simply >> there to stop the machine ramming the end of the ballscrews ;) >Don't confuse limit and home switches. Limit switches prevent damage to >the machine (but should never be hit in real life). >Home switches determine where your machine's zero location is. I'm not :) Why should "home switches" necessarily define where your machines zero location is? They should be able to be set at any arbitrary numbers you like, as long as the controller knows where they are and can make the relationship between them, the work coordinates and the machine limits. It doesn't matter a jot what the figures are, as long as the machine can go there ;) For all intents and purposes, machine coordinates are irrelevant to an operator. They are a machine setup value that work in the background, in most commercial shops the only person who ever needs to access them is the repair man. Steve Blackmore -- -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Soft/hard limits & homing (was: Re: emc2.3.0beta2)
Steve Blackmore wrote: > Softlimits? I don't use them. I have limit switches, I don't use them > either, I think since the eighties I've hit them twice. They are simply > there to stop the machine ramming the end of the ballscrews ;) > > I don't directly use "machine coordinates" either, they are meaningless > to me as an operator. I, and many others, are only interested in work > coordinates. What the Controller thinks they are is irrelevant to me, as > long as I've told it where the work zero's are that should be > sufficient. > > All I want is to simply tell it where X0 Y0 Z0 are in relation to mill > stock, Don't confuse limit and home switches. Limit switches prevent damage to the machine (but should never be hit in real life). Home switches determine where your machine's zero location is. Machine coordinates are very useful for me. From my machine's zero I know exactly where the top-left position of my mill stock is, the center of my 4th axis and the left bottom position of the bottom left stop for large foam/wood blocks. And machine coordinates also determine where the tool changer is located. I plan to add more mill stocks so I can link multiple programs to make multiple parts without having to stop in between to insert a new blank (and do homing). So machine coordinates are very useful. One company I know does a lot of production of the same parts and the rely fully on machine coordinates in order to know where the blanks are located on their palleting system. They start of with a large block of aluminum in which a number of plugs for the palleting system are mounted, then they mill one side of the block, mount the half finished workpiece in a countermold (which is placed on the palleting system) and mill the other side. Here the zero point of the workpiece is solely determined by using machine coordinates and making multiple of the same parts would be hardly possible without it. Regards, Rob -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
