Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Naijin on April 27, 2014, 06:48:45 AM
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Hi there, to-day I tried to set the limit switches on my 3 axis mill, they seem to work o.k. except when the switch is activated the machine stops and winds back,BUT it does not wind back far enough to de-activate the switches, is there a setting somewhere to have the software to take a few more steps to clear the switches?
Regards
Nick
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Hi Nick,
Mach3 will back off until the switch de-activates.
You are probably, dependant on the quality of your switches, seeing 'switch bounce' which is confusing the issue. This problem can usually be resolved by fitting miniature 0.1uF capacitors between each switch input and GND at your breakout board (or where you have connected the switch wiring to your controller). A secondary solution is to increase the Debounce Interval in Config / General Config.
Hope this helps,
Tweakie.
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Thanks for the info Tweekie, I have solved the problem by adjusting the position of the limit switches and it works fine, All I need now is a step by step instruction on how to set them all up for homing and limits etc.
Regards
Nick
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Very short answer is: RTFM
Everything that you need is explained in written form.
Vision impaired people are "guided" across the street, ...
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Thanks Zasto, I have read the manual, watched the videos, and yet I have difficulty understanding how the whole process works. I have referenced all the axis as per instructions but it still won't cut in the right direction e.g I will jog it to where I want it to cut, zero the axis, instead of going in the x+ and y+ direction to cut it will actually move to the x- and y- an then start to cut. It is not the lack of reading the manual, but probably lack of understanding how it works.
Nick
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In the config screens, possibly ports & pins, there is an option to reverse direction, try flipping that on or off.
I am not in front of Mach at present so I am guessing, but it is there.
Have you got limit switches at both ends of the X & Y axes?
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If it is homing in the right direction - bottom left corner, then flipping the reverse flag will likely change this. there is another box for homing direction that will likely need doing as well.
Once it is jogging and homing correctly then move on.
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Hi Davek0974, Yes I have switches at bot ends of the x and y axis, it is actually homing in the right direction e.g bottom left hand corner, it is jogging in all the right directions, but when I move it for example: the work is located at Y=50, X=100, that is the position I want the program to start cutting at, when I hit the cycle run switch it will move in the X and Y negative position and then start to cut, I should have mentioned that I am running Mach3 2010 screen set.
Nick
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Hmmm, what does the G-code say?
Does it look logical?
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The G-code is good, I have run the same code before I changed screen sets, and had no problems with it, it ran from where it was told to run from, and in the right direction too!
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Thanks Zasto, I have read the manual, watched the videos, and yet I have difficulty understanding how the whole process works. I have referenced all the axis as per instructions but it still won't cut in the right direction e.g I will jog it to where I want it to cut, zero the axis, instead of going in the x+ and y+ direction to cut it will actually move to the x- and y- an then start to cut. It is not the lack of reading the manual, but probably lack of understanding how it works.
Nick
You messed something with settings.
Here are settings for a router that I'm using.
Machine is homing to the lower/left, jogs in the right directions, executes G Code in right directions.
As you will notice, I'm using same switch for Home/-- limit and Soft Limits.
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Ok thats good.
If you press tab to get jog control up, then press the up arrow on the keyboard, does the the gantry move away from zero/home position i.e does it move in a positive direction??
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Thanks Zasto, I have read the manual, watched the videos, and yet I have difficulty understanding how the whole process works. I have referenced all the axis as per instructions but it still won't cut in the right direction e.g I will jog it to where I want it to cut, zero the axis, instead of going in the x+ and y+ direction to cut it will actually move to the x- and y- an then start to cut. It is not the lack of reading the manual, but probably lack of understanding how it works.
Nick
You messed something with settings.
Here are settings for a router that I'm using.
Machine is homing to the lower/left, jogs in the right directions, executes G Code in right directions.
As you will notice, I'm using same switch for Home/-- limit and Soft Limits.
Thanks for the pics Zasto, I have some of the settings different, but after changing them to look very similar to yours, it worked, I still not sure if I understand the X++ and Y++ etc, what they actually do if the whole lot of them were enabled like mine were, I could not find it in the manual, where it says you either enable one or the other or both, e.g Y++, X++, Y-, and X-, I may have overlooked it or didn't understand the explanation, OR maybe ALZHEIMERS is starting to kick in!!
Cheers
Nick
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Ok thats good.
If you press tab to get jog control up, then press the up arrow on the keyboard, does the the gantry move away from zero/home position i.e does it move in a positive direction??
Yes Davek0974, all the jog keys work in the right direction, my settings in the ports and pins setting were a little bit out
Cheers
Nick
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X++, Y++ and Z++ limit switches are at the opposite sides of their "--/Home" counterparts :)
I don't have "++" switches on my Chinese router, so I have Soft Limits active. Soft Limits are in Machine Coordinates.
Note that the axes in Home/SoftLimits settings are reversed, that means that during RefAllHome Z will travel in positive direction and X and Y axes will travel in negative direction, i.e. towards Home ("--") switches/sensors.
HTH
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X++, Y++ and Z++ limit switches are at the opposite sides of their "--/Home" counterparts :)
I don't have "++" switches on my Chinese router, so I have Soft Limits active. Soft Limits are in Machine Coordinates.
Note that the axes in Home/SoftLimits settings are reversed, that means that during RefAllHome Z will travel in positive direction and X and Y axes will travel in negative direction, i.e. towards Home ("--") switches/sensors.
HTH
Thanks very much ZASto, that really helped to explain it
Cheers
Nick
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You are welcome.