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Limit switches
« on: January 16, 2016, 03:38:44 PM »
Hi
I have just rewired all my limit switches with shielded cable, in series NC. I have tried a few times to set them up in MACH 3 ports and pins input signals but Mach 3  doesn't see them, I have checked the wiring with meter they are all working, they worked before i rewired but I was getting false tripping. Do I need to reset Mach 3 to set them up or is there something else I might check.
Thanks Bill

Offline Hood

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Re: Limit switches
« Reply #1 on: January 17, 2016, 05:36:31 AM »
If the Limit LEDs do not show when you trip them then the signal is not getting to Mach.
Could be wrong inputs and port set in Ports and Pins, Inputs.
Coule be a problem with the breakout board.


Test at the port with a multimeter if you can, to see if the signals get as far as the port.
Hood
Re: Limit switches
« Reply #2 on: January 17, 2016, 03:39:02 PM »
Hi
I figured out my problem, I had emailed the company that makes the machine to find out were to hook up th-5v because there was not a -5v shown on the breakout board they said to use -5v off the power supply, there was not a terminal on the cpu power unit so I used the -5v on the driver power unit. as I learned since that will not work, a friend helped me find a -5v on the breakout board and now works fine. I am learning slowly. I have the limits working now but my orientation for my display is not right . it homes out side the table perimeter display and moves away from it instead of into it. the same happens when I load the roadrunner it displays just out side of the home coordinates.
Bill
Re: Limit switches
« Reply #3 on: January 17, 2016, 03:48:46 PM »
One other thing I don't understand as I said in the last post I rewired my limits with shielded cable because when I set up the first time I was having trouble with the limits tripping. I had used the -5v from the driver power supply. The switches did work but when my friend helped me trouble shoot to fix this new problem he said that can't work because the power from the breakout board for the pins  is coming from the cpu power unit, he used the example that if you had two 12v car batteries and connected the positive to one and the negative to the other that the electrical would not work, there is no return. I don't know why it worked the first time for me.

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Re: Limit switches
« Reply #4 on: January 17, 2016, 03:52:07 PM »
Table display is controlled by the soft limit values.
Sounds like you may be homing top right and if that is the case you can do one of two things.
1. you can set a Home Off value equal to the axes lengths so that when you home instead of the machine coords going to zero they will go to the max value that axis can travel.
Example, you have X travel of 500mm, you home to the right so you set a Home Off value of 500 in Homing and Limits page. When you now home the machine coords will show 500 and Mach will know the X zero in machine coords is 500mm in the negative direction. The same would be done for Y if you are homing to the top corner.
Then you would just set the soft limit values of X and Y min to zero and X and Y Max to the axes length.


The other option would be to  put negative values equal to the axes lengths in the Soft Limits page for X and Y Min.

Personally I would do option 1 .

Hood
Re: Limit switches
« Reply #5 on: January 17, 2016, 04:11:41 PM »
Hi
My working size is 96" x and 24" y I want to home to the bottom right hand corner. I will adjust what you have recommended and see if that works.
Thanks for your interest
Bill
Re: Limit switches
« Reply #6 on: January 17, 2016, 05:17:38 PM »
Hi
Couple of questions . when I closed Mach 3 the last time after setting up my limits switches it asked me in a box"fixture save" I clicked yes . when I reopened to see if I could reset my soft limits I played around with the X and Y entries in the soft limit section and looked at the display to see if the orientation of the work area changed it did not show at all, the roadrunner came up and this time it was the full area of the display box not small like before in relation to my work area. I reset to the old numbers but it still doesn't show the work area. When I tried to reference home the Z went way out of the soft limits. this is all in the program I did not have the machine turned on. did that fixture save do something to my settings
Bill

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Re: Limit switches
« Reply #7 on: January 18, 2016, 04:28:55 AM »
Ok there are two views you cn see the toolpath as, table view and prt view. If you have it in table view you will see the working area outline as defined by your soft limits. If you have it in Part view then it will show the part only.
  If you have the work coords  way off from the part it may still look small even in part view, if however the work coords correspond to the parts coords then it will show full screen.


To change between views you press the display button then press Regen button.

Hood