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mach4 homing
« on: May 27, 2020, 11:09:39 AM »
I am newbie at mach4 I am trying to homed all axis, but i do not see a button for homed, the only button i see is reference all axis (home), but i can inter a g code g28 x0.0 y0.0 and z0.0 it will go homed. please help.. My  Ver Thanks :o

Offline Bill_O

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Re: mach4 homing
« Reply #1 on: May 27, 2020, 12:46:33 PM »

Reference All is the Home function.
Just different name.
Depending on what is programed in the button it should work just like the G28

Re: mach4 homing
« Reply #2 on: May 27, 2020, 11:37:10 PM »
I am not sure you talking about (Depending on what is programed) i am running latest ver of mach4 but its what i am trying to do is do a homed command , what i have done is setup in soft limit . what i have done is put my axis at my position and hit Reference all axis and it will go to 0.0000 on x x and z with no movement but at 0.0000... then i move my all axis and reboot the mill when then i hit the reference all axis noting happen.. but axis said 0.0000 with no movement .. I have watch some videos with no success.. ya am a 60 year old newbie. please help Thanks   
Re: mach4 homing
« Reply #3 on: May 27, 2020, 11:54:54 PM »
do you have Home switches assigned and working?

I notice you say you have set up SoftLimits. SoftLimits only make any sense if you have Home switches and you reference (or home) your machine at start-up.

In absence of Home switches Mach will 'Home In Place' that is, the machine coordinate DRO's will reset to zero but without movement. If you have
home switches then the machine will move until it detects switch activation.

The 'depending on whats programmed' that Bill_O refers to is the small script within the ScreenLoad Script that determines the behaviour
of the <RefAllHome> button.

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Re: mach4 homing
« Reply #4 on: May 28, 2020, 02:58:00 PM »
So i do have to put  an actual limit switch? i thought you could use soft limits but i guess i was mistaken. where can i get the script if i decide to stay with soft limits? thanks for the help.   

Re: mach4 homing
« Reply #5 on: May 28, 2020, 03:22:03 PM »
you are confusing home and limit switches.

When you use SoftLimits you are declaring to Mach that the extents of the machine are so many inches in the X
direction, so many inches in the Y direction etc from your Home point.

So how do you deterime your Home point? Today when you started your machine and pressed <RefAllHome>
you were 4 inches from the lefthand end of the X axis and 3 inches from the end of the Y axis.
Tomorrow when you start your machine but this time when you press <RefAllHome> you are six inches from
the lefthand end of the X axis and 6 inches from the end oy the Y axis.  Thus the data that Mach was using to determine
the 'SoftLimits' was correct on day one, but now your Home point has shifted on day two its incorrect.

The only way for SoftLimits to work properly is for the Home point to be a uniquley defined and REPEATABLE place
on your machine. That is what home switches are for.

You could use three of your limit switches to determine one 'corner' of your machine and call that Home. My preference
is to have separate home switches as you can determine the design, mounting and location of the switches to give
the best possible repeatability of the home loaction.

My wife left with my best friend...
     and I miss him!
Re: mach4 homing
« Reply #6 on: May 29, 2020, 02:20:08 AM »
OK i under stand now so the RefAllHome is for a place like a spot on my table, well thanks for the information ,but i am now installing limit switch on it this weekend Thanks for your help Craig  8)