Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: cesser85 on May 28, 2014, 12:06:26 AM
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Hello,
I am setting up a new build and am having trouble with Homing the Z-Axis.
I am using 1 pair of limit switches per axis (X, Y, Z), with the two switches wired in parallel. I also use these limit switches for homing all my axes. The X and Y axes home just fine, exactly like you would expect, however the Z axis will not home. As soon as I hit 'Ref All', The Z-Axis indicator will flash RED for about half a second and then show GREEN, for being homed. The other axes will then move through their homing cycle. I have checked that the Z-Axis limit switches aren't being tripped in the starting Z position and that they are being read by Mach3, as seen in the Diagnostics Screen. The Z-Axis Limit switch will also stop motion if it is triggered.
Any ideas why X and Y will home properly, but the Z-axis is being skipped over?
Thanks,
Chris
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Hello,
I'm new here. I too am having Z-Axis problems. I figured I'd post is this forum as opposed to starting a new one. Hopefully it will help the next person. My issue is that I can't figure out how to position my bit. Meaning, when I want to go from a 1 inch thick board to a 2 inch thick board how do I change the settings so that it starts an stay above 2 inches and vice versa. I have a CNC 3020.
Thank you for your help
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Hello,
Any ideas why X and Y will home properly, but the Z-axis is being skipped over?
Thanks,
Chris
Double check that the Z HOME is enabled and assigned correctly.
Russ
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Russ,
Yes I do have the Z-Axis homing assigned and enabled. Please see the attached pictures.
The same Z-Axis Limit switch I want to use for homing is also my limit switch, and it does work correctly for that function.
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I think your pin number maybe incorrect. input pin can only be 10-13 and 15, the y is also wrong.
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I'm not using a parallel port for my IO, I'm using a USB Motion Card, the AKZ250, so there are more IO pins available. I do know that my limit switches are configured correctly, they activate correctly when looking at the Diagnostics screen and it works to stop machine motion when it is triggered.
Here is a link to my motion card.
http://www.automationtechnologiesinc.com/products-page/breakout-boards/3-axis-cnc-usb-card-mach3-200khz-breakout-board (http://www.automationtechnologiesinc.com/products-page/breakout-boards/3-axis-cnc-usb-card-mach3-200khz-breakout-board)
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To make sure I am reading your post corrector. The Z homes and reset to 0 without hitting limit switch.( home in the incorrect position) That sound like you have noise on the Z switch wiring. To trouble shoot try moving the Z limit wires away from any other wires. You mite play around with the debounce controls in the General Config.
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Yes, that is correct. Both X and Y home just fine, but Z just takes its current position as home. Here is the sequence of events. I've attached screen shots
1) Start up (All axes show up as RED, so not referenced)
2) Click 'Ref All'. Z immediately shows GREEN and takes its current position as its machine coordinate
3) Y homes normally
4) X homes normally. This is where it finishes
The Z-axis never actually moves at all. It is just being skipped in the Homing sequence, as if the axis wasn't enabled. To me it seems like I have a setting somewhere that is telling Mach3 to only home X and Y, and skip Z.
I have checked the wiring and know that it is correct. The limit switch I use for homing works just fine as a normal limit switch. I've attached the Diagnostics screen (next post) showing all three limit switches in a triggered position. I manually moved the machine to get them all to go. One inconsistent thing is that all the M3 (Z-Axis) values are a larger font than the other 2 (X and Y). I have no idea if this means something or is just random.
Thanks for your help!
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Here is my diagnostic screen and settings screen.
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I did not think you had a miss wire but some wire were induction ele noise into the Z lines but I was also thinking the system was zeroing the Z and I see that is not the case. So forget the noise idea.
I am at a lost.
Does the z ever move/run, jog or step?
Stepper or servo motors?
I would probably swap pin 1 and 2 in the Engine Config Port and Pins and then change in the Motor Home and Soft Limits, Home neg on Y and Z. To see if problem tracks.
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Thanks again for your help.
Yes, the Z-Axis works just fine, with the exception of this homing issue. I am using Stepper motors + Gecko Drives.
I did as you suggested and swapped Pins 1 and 2, effectively swapping the limit switches for Y and Z. The problem did not track the limit switch, but stayed with the Z-Axis. Again it homed just fine (expect that I had to manually trip the switches, since the axis was looking for the wrong switch), but the Z-Axis was skipped.
Any other ideas? Is there another level of homing settings past the 'Motor Home/Soft Limits' page? Somehow the Z-Axis is set to just take its current position instead of looking for a switch?
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Did a search on this and came up with this
http://www.machsupport.com/forum/index.php/topic,26997.0.html
also looking thru the manual found
Engine Config - Mill Option - Z-Inhibit not checked. General Option not checked. not sure either has anything to do with your problem. You know I have run out of Idea when I start reading the manual.
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Hi. I tried that, it didn't have any effect.
I've also tried creating a brand new Milling profile, but that still didn't work.
What I'm trying now is installing Mach3 on a totally different computer and starting from scratch. Hopefully that will work.
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So I just tried doing a fresh install on a brand new laptop with the most recent version of Mach3 and I am having the exact same issue. I am using the Demo version of Mach3 right now, could that have an effect on it? Is that one somehow limited to only 2 axes for homing? All three axes work just for motion, so that would be an odd limitation.
There must be a setting somewhere that I'm missing. Or maybe it has something to do with my motion card? But since all the limit switches work and the axes move correctly, I don't see how that would affect the homing cycle.
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After doing a clean install is the M3 font still different then the rest?
Ray