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How to over ride limit switches?
« on: May 26, 2009, 12:26:22 PM »
I just installed limit switches on my gantry router.   I am using a Gecko G540.   The limit switches work great but once they are tripped I don't know how to disable them to start the machine again.  Where is the override button in Mach3 ???

Thanks for any assistance you might offer!!!

Jack

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Re: How to over ride limit switches?
« Reply #1 on: May 26, 2009, 01:26:14 PM »
You have two options and both on Settings page.
1. OverRide Limits, this will allow you to press the Reset and jog off the limit but will need pressed every time you hit a limit.

2. Auto Limit OverRide, this stays set and will allow you to just press the reset and jog off a limit right away without having to go to the settings page.

You should also look into setting the softlimits up, it will 99.99% of the time stop you actually hitting the physical limits.

Hood
Re: How to over ride limit switches?
« Reply #2 on: May 26, 2009, 02:05:46 PM »
Hood,

Thanks, got the auto limit override set up!   It seems to require me to reset try jog reset again and then jog works to get off the limit switch.  Is this correct? 

I will look into setting up the soft limits as it makes sense to use software rather than hardware when possible.   I like "belt and suspenders" approach when it comes to a dangerous machine.

I have to say that I like the Mach3-Gecko G540 system!

Again, thanks for your patience!

Jack

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Re: How to over ride limit switches?
« Reply #3 on: May 26, 2009, 02:11:41 PM »
It should allow you to Jog off after pressing the Reset once only. I suspect your switches are a bit bouncy and Mach is seeing them close as you start to jog off but then they open for a micro second and Mach reasserts the E-Stop condition. You could try increasing the debounce interval on the General Config page, try 2000, if it helps then work your way down to the lowest number you can.

Yes I agree, I wouldnt have a machine that does not have physical limit switches either.

Hood
Re: How to over ride limit switches?
« Reply #4 on: May 26, 2009, 02:42:14 PM »
Hood,

Thanks, no more bounce at value of 10.   Very nice indeed.

I have been tinkering and am getting 200 ipm rapids.

Now all I have to figure out is how to configure Soft Limits and Home. 

Hope you don't mind more questions. I sure appreciate your help.   I think when this machine is properly configured I will have learned a bit and have a good machine.

Regards,

Jack

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Re: How to over ride limit switches?
« Reply #5 on: May 26, 2009, 02:48:43 PM »
If your Home switches (can be limits configured also as home) are at the normal positions, ie table fully right, fully towards column and Z fully up then set the SoftLimits as follows.
 X and Y min and Z max set to zero
 X and Y max  set to the travel of each axis
 Z Min set to travel of Axis but a negative number.

Enable Softlimits on main page and you should be set.

You will also need to set up a slow zone for each axis, this is machine dependant so you will have to experiment by jogging towards a limit at rapid speed then seeing if the softlimits can decelerate in time before a limit is hit, just keep messing until you find the minimum distance that will keep you from hitting the limits.

Hood
Re: How to over ride limit switches?
« Reply #6 on: May 27, 2009, 07:50:15 AM »
I get a "machine out of limits" message when I try to enable soft limits on the main page???

Jack

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Re: How to over ride limit switches?
« Reply #7 on: May 27, 2009, 07:58:01 AM »
Reference the machine then enable them, also make sure you have Auto Zero enabled on Homing and Limits page. If you still dont manage then I would guess your home switches may be at a position other than specified above. If they are at the other end (Table fully left or fully forward) then you will need to put a Home off value of the axis travel  for each axis that is set up that way.
Hood
Re: How to over ride limit switches?
« Reply #8 on: May 28, 2009, 09:51:32 AM »
Switches are at each end of travel on each axis.

X axis would have value of 0" and 42"
Y                                   0" and 16"
Z                                   0" and -6"

Jack

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Re: How to over ride limit switches?
« Reply #9 on: May 28, 2009, 11:06:04 AM »
Which end do you have set up as Home switches?
Hood