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        <title>Z axes do not home correctly anymore</title>
        <description> Hi!

I have totally no idea where best to post this, but I thought it might have something to do with the RAMPS 1.4 microprocessor that I use.

I have been quite happily printing for a while now. Today, I printed a big part (about 8 hrs printing), but I had to stop it prematurily (emergency shutdown). I did this using the emergency shutdown of the Repetier software. However, after that, I hit the Z axis home button. While this should have homed the Z axis (to the top), the axis only moved for a small distance down?... Then it stopped. I can keep on doing this, and always the same happened. 

BTW: I use 2 Z axes, so the motors themselves shouldn&#039;t be to blame (would be strange if both be broken)?

I did the following:
 Reboot RAMPS 1.4 Reboot controlling PC Reinstall the firmware (marlin) Replace the motor driver for my two motors of the 2 Z axes Try to print something

Always the same problem... For now, printing is out of the question :-(

Did anyone have such a problem? Could it be that my RAMPS board is fried for some reason? Maybe using the &quot;emergency shutdown&quot; function of the Repetier Software is extremely unhealthy?

Thanks for any ideas!</description>
        <link>https://reprap.org/forum/read.php?219,448824,448824#msg-448824</link>
        <lastBuildDate>Sun, 13 Sep 2026 10:49:21 -0400</lastBuildDate>
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        <item>
            <guid>https://reprap.org/forum/read.php?219,448824,448959#msg-448959</guid>
            <title>Re: Z axes do not home correctly anymore</title>
            <link>https://reprap.org/forum/read.php?219,448824,448959#msg-448959</link>
            <description><![CDATA[ BTW: I exchanged the optical switch for the Z axis by a mechanical switch now. Hope that'll prove to be more reliable (and easier to notice if it is broken)!<br />
<br />
Thanks all!!]]></description>
            <dc:creator>Stephanel</dc:creator>
            <category>RAMPS Electronics</category>
            <pubDate>Mon, 29 Dec 2014 20:27:09 -0500</pubDate>
        </item>
        <item>
            <guid>https://reprap.org/forum/read.php?219,448824,448958#msg-448958</guid>
            <title>Re: Z axes do not home correctly anymore</title>
            <link>https://reprap.org/forum/read.php?219,448824,448958#msg-448958</link>
            <description><![CDATA[ I couldn't sleep so I did some more testing. I found another optical switch laying around, and exchanged that with the old one. And miraculously, it works again!<br />
<br />
I switched back to the old one, and things go wrong again...<br />
<br />
So it seems like the optical switch itself is broken. However, the light still goes on and off when I wave something in front of it, but it seems for some reason the info is not sent to the RAMPS board.<br />
<br />
Do you guys have experience with the reliability of such optical switches (<a href="http://www.aliexpress.com/item/Photoelectric-Optical-Stop-Switch-End-Stop-for-3D-Printer/32227648132.html" target="_blank"  rel="nofollow">like this one</a>)? The reliability of this one is crap (only a few months), and the fail mechanism is strange to say the least...<br />
<br />
I will perform more tests on it tomorrow to try and find more about the fail mechanism. Hope it'll help another guy having these issues!<br />
<br />
Steph]]></description>
            <dc:creator>Stephanel</dc:creator>
            <category>RAMPS Electronics</category>
            <pubDate>Mon, 29 Dec 2014 20:25:24 -0500</pubDate>
        </item>
        <item>
            <guid>https://reprap.org/forum/read.php?219,448824,448955#msg-448955</guid>
            <title>Re: Z axes do not home correctly anymore</title>
            <link>https://reprap.org/forum/read.php?219,448824,448955#msg-448955</link>
            <description><![CDATA[ Maybe try M503 to see if a Z offset has been set in EEPROM, or send M206 Z0 to set 0 Z offset?]]></description>
            <dc:creator>Anonymous User</dc:creator>
            <category>RAMPS Electronics</category>
            <pubDate>Mon, 29 Dec 2014 20:03:42 -0500</pubDate>
        </item>
        <item>
            <guid>https://reprap.org/forum/read.php?219,448824,448946#msg-448946</guid>
            <title>Re: Z axes do not home correctly anymore</title>
            <link>https://reprap.org/forum/read.php?219,448824,448946#msg-448946</link>
            <description><![CDATA[ That's correct. I did also check the wiring, but didn't do the M119 command. After checking the wiring again, I still get the same problem. This is what I get when I execute the M119 command:<br />
<br />
00:55:19.201 : Reporting endstop status<br />
00:55:19.201 : x_min: TRIGGERED<br />
00:55:19.201 : x_max: open<br />
00:55:19.201 : y_min: TRIGGERED<br />
00:55:19.201 : y_max: open<br />
00:55:19.201 : z_min: open<br />
00:55:19.201 : z_max: open<br />
<br />
Both X and Y axes actually are at home position. Z axis is not yet at home position, however it still moves down about 2mm when I do "G28 Z". Note that it does not perform the home positioning (slowing down and then moving down and up) but only moves down 2mm. Also, I now notice that if I do the homing, the Z axis cannot move down below that point. It seems as if the 0 point of the Z axis has been changed...<br />
<br />
Note that this all started without any changes to firmware or any hardware...<br />
<br />
I have manually moved up the Z axis to the end trigger and it seems to work correctly:<br />
<br />
01:00:06.680 : Reporting endstop status<br />
01:00:06.680 : x_min: TRIGGERED<br />
01:00:06.680 : x_max: open<br />
01:00:06.680 : y_min: TRIGGERED<br />
01:00:06.680 : y_max: open<br />
01:00:06.680 : z_min: open<br />
<b>01:00:06.680 : z_max: TRIGGERED</b><br />
<br />
Could there be another reason for the malfunctioning?<br />
<br />
Thanks!]]></description>
            <dc:creator>Stephanel</dc:creator>
            <category>RAMPS Electronics</category>
            <pubDate>Mon, 29 Dec 2014 19:21:33 -0500</pubDate>
        </item>
        <item>
            <guid>https://reprap.org/forum/read.php?219,448824,448872#msg-448872</guid>
            <title>Re: Z axes do not home correctly anymore</title>
            <link>https://reprap.org/forum/read.php?219,448824,448872#msg-448872</link>
            <description><![CDATA[ Normally happens when your Z axis end stop has become disconnected.  Check the wiring and send M119 to the printer to see end stop status.]]></description>
            <dc:creator>Anonymous User</dc:creator>
            <category>RAMPS Electronics</category>
            <pubDate>Mon, 29 Dec 2014 16:26:58 -0500</pubDate>
        </item>
        <item>
            <guid>https://reprap.org/forum/read.php?219,448824,448824#msg-448824</guid>
            <title>Z axes do not home correctly anymore</title>
            <link>https://reprap.org/forum/read.php?219,448824,448824#msg-448824</link>
            <description><![CDATA[ Hi!<br />
<br />
I have totally no idea where best to post this, but I thought it might have something to do with the RAMPS 1.4 microprocessor that I use.<br />
<br />
I have been quite happily printing for a while now. Today, I printed a big part (about 8 hrs printing), but I had to stop it prematurily (emergency shutdown). I did this using the emergency shutdown of the Repetier software. However, after that, I hit the Z axis home button. While this should have homed the Z axis (to the top), the axis only moved for a small distance down?... Then it stopped. I can keep on doing this, and always the same happened. <br />
<br />
BTW: I use 2 Z axes, so the motors themselves shouldn't be to blame (would be strange if both be broken)?<br />
<br />
I did the following:<br />
<ul><li> Reboot RAMPS 1.4</li><li> Reboot controlling PC</li><li> Reinstall the firmware (marlin)</li><li> Replace the motor driver for my two motors of the 2 Z axes</li><li> Try to print something</li></ul>
<br />
Always the same problem... For now, printing is out of the question :-(<br />
<br />
Did anyone have such a problem? Could it be that my RAMPS board is fried for some reason? Maybe using the "emergency shutdown" function of the Repetier Software is extremely unhealthy?<br />
<br />
Thanks for any ideas!]]></description>
            <dc:creator>Stephanel</dc:creator>
            <category>RAMPS Electronics</category>
            <pubDate>Mon, 29 Dec 2014 14:11:05 -0500</pubDate>
        </item>
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