<p>Mine is doing the exact same thing on the latest Marlin Bug Fix, Ender 3 Pro, 4.2.7 board and CR Touch. On the 7th point it pushes super far into the bed and engages the springs. There must be a bug, I am going to compile the standard release and see if the same thing happens.</p>

CC BY-SA 4.0
2023-01-25T13:45:40.843Z
Hi and welcome. This answer seems to be a cross between a "me too" type comment and a speculative fix (which, again, would serve better as a comment). Please [edit] and update your answer with a definitive solution as soon as you are able, otherwise this answer *may* be converted to a comment under the question... Also, please take the [tour].
Greenonline
CC BY-SA 4.0
2023-01-25T04:30:46.380Z
2023-01-25T04:31:41.470Z
2023-01-25T04:31:41.470Z
Y2J
<p>Your CR Touch is either installed wrong or broken.</p>
<p>Auto home checks for the X and Y limit switches then goes to the center of the bed and drops the CR probe tip. The probe color should be total blue and the tip of the probe should drop about 5-6 mm, going well past the end of the nozzle.</p>
<p>The Z moves down, the probe tip touches, the probe is pushed into the assembly, and the light turns red. When the light goes red, the nozzle tip should still be somewhere around 1.8 to 2.0 mm above the plate. This is the Z-offset, it’s entered as a negative because that much further the nozzle must move in Z to reach the bed.</p>
<p>Repeat the measurement, retract the tip, move Z +10 mm, and stop. The probe tip when retracted should be above the nozzle tip maybe 1-2 mm.</p>
<p>If Auto home works as described above, the CR Touch is set up and working ok.</p>
<p>The problem is your Z-offset.</p>
<p>Set Z-offset to -5.0 mm. Run Auto Leveling, it should complete without the nozzle hitting the bed.</p>
<p>Run this procedure to set a reasonable Z-offset.</p>
<p>Set Z-offset to -1.72 mm on the display. Run a test print of anything. If you see string coming out of the nozzle and not sticking to the bed at all stop the print. Set Z-offset to -1.74 mm. Repeat.</p>
<p>Continue to move down this way in -0.02 mm steps until something starts to stick, then once or twice more until you can run the test print successfully to the end.</p>
<p>Run Auto Leveling it will work.</p>
<p>Alternatively, the nozzle is not installed or tightened correctly so it extends too low.
Lastly, gross mechanical misalignment.</p>

CC BY-SA 4.0
2023-01-01T11:21:37.890Z
After re-reading everything again. The reason you crash and the auto leveling stops is because of the Z-offset set near 0.0.
Robert Barnes
CC BY-SA 4.0
2023-01-01T11:39:45.853Z
The reason it stops at the 7th location is because that corner of your bed is high despite some sort of manual leveling. With a near 0.0 Z-offset the nozzle tip is barely floating above the bed the whole time and crashes on the high corner. The nozzle should be cruising easily 2 mm above the bed while the probe measures the delta z from the offset at various positions to make its correction map.
Robert Barnes
CC BY-SA 4.0
2023-01-02T11:15:51.690Z
@agarza I don´t think its a hardware or installation problem as it aligns with the screw holes for both the extruder and the br touch itself). It´s a thing of callibration or software issue.
Today I tested a print and the cr touch didnt stop for the first measurement at the center neither, but went down too far smashing the bed with the nozzle.
Also, I cannot calibrate the offset to negative values as 0.0 is the point where the paper is barely movable, so I cannot go any further.
Diego Manzanares
CC BY-SA 4.0
2023-01-02T19:54:34.427Z
You say you are new to this, but you’re doing a lot of significant upgrades to the machine. Is this a “new out the box” machine or an older machine restoration? Most of the videos on YouTube are new machine setup demos for newbies.
Robert Barnes
CC BY-SA 4.0
2023-01-02T20:19:01.653Z
In either case, the “gross misalignment” I mentioned applies but it’s probably not too bad. Overall, the whole of the bed is too high. Mark the front of each adjustment wheel and then turn each two full turns to tighten the springs and lower the bed. You should need to dial in a negative Z-offset to get the nozzle on the bed at this point. Try Auto home and leveling.
Robert Barnes
CC BY-SA 4.0
2023-01-03T21:05:16.737Z
If your machine is a straight Ender 3, did you remove the Z-limit switch and hard stop assembly when installing the CR Touch? You can’t really have both.
Robert Barnes
CC BY-SA 4.0
2023-01-03T21:47:33.343Z
These are both methods of signaling (through change of state) what the Z-axis zero point is.  The advantage of the CR Touch is the repeatability of this signal relative to the bed.  I hope this works for you, it explains all symptoms you have reported so far.
Robert Barnes
CC BY-SA 4.0
2023-01-05T07:46:56.603Z
I did remove the Z limit switch while installing and tried to lower the bed down, but the offset is still at zero. I´m going crazy now hahaha.
Diego Manzanares
CC BY-SA 4.0
2023-01-01T10:44:42.813Z
2023-01-01T14:11:24.017Z
2023-01-01T14:11:24.017Z
Robert Barnes
<p>Just came to the 3D printing world and after installing Marlin 2.1.2 firmware in my Ender 3, which took a while and was finally completed following this tutorial:
<div class="youtube-embed"><div>
                <iframe width="640px" height="395px" src="https://www.youtube.com/embed/EGyKCSWJYls?start=0"></iframe>
            </div></div></p>
<p>I cannot get the CR Touch correctly calibrated, but it is correctly installed (physically) and recognized in firmware. The steps I´m following are:</p>
<ul>
<li>Auto-homing. Which does a correct measurement from the center of the bed using CR Touch.</li>
<li>Probing the Z Offset. Which is strange because I got 0.1 mm instead of the -1.x mm or even -2 mm some people are getting in some tutorials I´ve seen so far.</li>
<li>Bed leveling. By default it takes 9 measurements and the first 6 are okay, but for the 7th the nozzle along with the CR Touch goes to low and pushes against the glass bed. Also, is there a way to make it work taking more measurements of the bed? Just for it to be more accurate and know more the bed it is working on.</li>
</ul>
<p>Once again, I´m new in this but I have seen many videos about it, not getting a valid configuration in any of them. Is there anything to try out for it to work well? Also, I´m using OctoPrint for it, in case this helps or there is a known plugin I can work with.</p>

CC BY-SA 4.0
2022-12-27T08:32:42.550Z
Hey, what exactly is your problem here, besides 3rd point(Bed leveling)?
kosteklvp
CC BY-SA 4.0
2022-12-27T09:05:46.290Z
@kosteklvp the issue is that I cannot manage to calibrate correctly the CR Touch. I do the probing in Z Offset and when measuring the bed levels, 6 out of 9 points register correctly but the 7th goes too low and smacks the bed until it stops with a message saying that the printer halted and needs to restart.
Diego Manzanares
CC BY-SA 4.0
2022-12-27T12:01:01.827Z
Nozzle goes down on 7th point? Did you level your bed manually, e.g. with a piece of paper? Can you share your firmware source code? I would like to take a look at it.
kosteklvp
CC BY-SA 4.0
2022-12-27T14:05:34.000Z
@kosteklvp yes, I did a manual leveling, but isn´t CR Touch supposed to avoid this? What I understood was that it measures the bed level and saves the 9 points of reference for future prints. Also, how can I upload the firmware?
Diego Manzanares
CC BY-SA 4.0
2022-12-27T14:08:22.983Z
@kosteklvp, the firmware I booted into the printer is the same as shown in the video. Can you please check it from there? I wont have access to the physical printer for a couple days. Thanks
Diego Manzanares
CC BY-SA 4.0
2022-12-27T14:22:16.430Z
This video shows how to compile firmware for Ender-5, so it won't work for you. You can also find precompiled firmwares from official Creality site. Source code can be uploaded to some code repository(e.g. GitHub) and I'll have a look at it.
kosteklvp
CC BY-SA 4.0
2022-12-27T14:46:40.523Z
@kosteklvp but will a precompiled single firmware from creality work with the CR Touch too? I´m a little messed, I dont know if I have to boot only one .bin firmware file or I have to include 2 .bin in the sd, one for the printer itself and another for the CR Touch to work with it
Diego Manzanares
CC BY-SA 4.0
2022-12-27T15:08:22.233Z
Found one in creality´s website: https://www.creality.com/pages/download-ender-3?spm=..page_1934481.products_display_1.1
Will the one for Ender-3 Marlin2.0.6 CR-touch or BLtouch firmware be valid for my Ender 3 (having a 4.2.2 board)
Diego Manzanares
CC BY-SA 4.0
2022-12-27T19:07:42.470Z
You should boot just from one firmware file. CR-Touch is just another sensor. Look for firmware, which supports CR-Touch (it should have BLTouch or CR-Touch in the name). This one, which you pointed, should work for you. You can find pretty good instructions in "BL Touch Introduction", that is available above on Creality page.
kosteklvp
CC BY-SA 4.0
2022-12-27T19:14:18.440Z
Ok, I will try this as soon as I get to the printer. Thanks.
Diego Manzanares
CC BY-SA 4.0
2023-01-01T17:30:03.930Z
Hey. Have you managed to solve this issue?
kosteklvp
<creality-ender-3><bltouch><octoprint>
CR Touch under Marlin for Ender 3
Diego Manzanares
# CR Touch under Marlin for Ender 3

(Asked by: username_0 on 2022-12-27)

Just came to the 3D printing world and after installing Marlin 2.1.2 firmware in my Ender 3, which took a while and was finally completed following this tutorial:

I cannot get the CR Touch correctly calibrated, but it is correctly installed (physically) and recognized in firmware. The steps I´m following are:

* Auto-homing. Which does a correct measurement from the center of the bed using CR Touch.
* Probing the Z Offset. Which is strange because I got 0.1 mm instead of the -1.x mm or even -2 mm some people are getting in some tutorials I´ve seen so far.
* Bed leveling. By default it takes 9 measurements and the first 6 are okay, but for the 7th the nozzle along with the CR Touch goes to low and pushes against the glass bed. Also, is there a way to make it work taking more measurements of the bed? Just for it to be more accurate and know more the bed it is working on.

Once again, I´m new in this but I have seen many videos about it, not getting a valid configuration in any of them. Is there anything to try out for it to work well? Also, I´m using OctoPrint for it, in case this helps or there is a known plugin I can work with.

**Tags:** creality-ender-3, bltouch, octoprint
> **Comments:**
> **username_1**: Hey, what exactly is your problem here, besides 3rd point(Bed leveling)?  
> **username_0**: @kosteklvp the issue is that I cannot manage to calibrate correctly the CR Touch. I do the probing in Z Offset and when measuring the bed levels, 6 out of 9 points register correctly but the 7th goes too low and smacks the bed until it stops with a message saying that the printer halted and needs to restart.  
> **username_1**: Nozzle goes down on 7th point? Did you level your bed manually, e.g. with a piece of paper? Can you share your firmware source code? I would like to take a look at it.  
> **username_0**: @kosteklvp yes, I did a manual leveling, but isn´t CR Touch supposed to avoid this? What I understood was that it measures the bed level and saves the 9 points of reference for future prints. Also, how can I upload the firmware?  
> **username_0**: @kosteklvp, the firmware I booted into the printer is the same as shown in the video. Can you please check it from there? I wont have access to the physical printer for a couple days. Thanks  
> **username_1**: This video shows how to compile firmware for Ender-5, so it won't work for you. You can also find precompiled firmwares from official Creality site. Source code can be uploaded to some code repository(e.g. GitHub) and I'll have a look at it.  
> **username_0**: @kosteklvp but will a precompiled single firmware from creality work with the CR Touch too? I´m a little messed, I dont know if I have to boot only one .bin firmware file or I have to include 2 .bin in the sd, one for the printer itself and another for the CR Touch to work with it  
> **username_0**: Found one in creality´s website: https://www.creality.com/pages/download-ender-3?spm=..page_1934481.products_display_1.1 Will the one for Ender-3 Marlin2.0.6 CR-touch or BLtouch firmware be valid for my Ender 3 (having a 4.2.2 board)  
> **username_1**: You should boot just from one firmware file. CR-Touch is just another sensor. Look for firmware, which supports CR-Touch (it should have BLTouch or CR-Touch in the name). This one, which you pointed, should work for you. You can find pretty good instructions in "BL Touch Introduction", that is available above on Creality page.  
> **username_0**: Ok, I will try this as soon as I get to the printer. Thanks.  
> **username_1**: Hey. Have you managed to solve this issue?  

---

## 2 answers

### Answer by username_4 on 2023-01-01. Score: 1

Your CR Touch is either installed wrong or broken.

Auto home checks for the X and Y limit switches then goes to the center of the bed and drops the CR probe tip. The probe color should be total blue and the tip of the probe should drop about 5-6 mm, going well past the end of the nozzle.

The Z moves down, the probe tip touches, the probe is pushed into the assembly, and the light turns red. When the light goes red, the nozzle tip should still be somewhere around 1.8 to 2.0 mm above the plate. This is the Z-offset, it’s entered as a negative because that much further the nozzle must move in Z to reach the bed.

Repeat the measurement, retract the tip, move Z +10 mm, and stop. The probe tip when retracted should be above the nozzle tip maybe 1-2 mm.

If Auto home works as described above, the CR Touch is set up and working ok.

The problem is your Z-offset.

Set Z-offset to -5.0 mm. Run Auto Leveling, it should complete without the nozzle hitting the bed.

Run this procedure to set a reasonable Z-offset.

Set Z-offset to -1.72 mm on the display. Run a test print of anything. If you see string coming out of the nozzle and not sticking to the bed at all stop the print. Set Z-offset to -1.74 mm. Repeat.

Continue to move down this way in -0.02 mm steps until something starts to stick, then once or twice more until you can run the test print successfully to the end.

Run Auto Leveling it will work.

Alternatively, the nozzle is not installed or tightened correctly so it extends too low.
Lastly, gross mechanical misalignment.

> **Comments:**
> **username_4**: After re-reading everything again. The reason you crash and the auto leveling stops is because of the Z-offset set near 0.0.  
> **username_4**: The reason it stops at the 7th location is because that corner of your bed is high despite some sort of manual leveling. With a near 0.0 Z-offset the nozzle tip is barely floating above the bed the whole time and crashes on the high corner. The nozzle should be cruising easily 2 mm above the bed while the probe measures the delta z from the offset at various positions to make its correction map.  
> **username_0**: @agarza I don´t think its a hardware or installation problem as it aligns with the screw holes for both the extruder and the br touch itself). It´s a thing of callibration or software issue. Today I tested a print and the cr touch didnt stop for the first measurement at the center neither, but went down too far smashing the bed with the nozzle. Also, I cannot calibrate the offset to negative values as 0.0 is the point where the paper is barely movable, so I cannot go any further.  
> **username_4**: You say you are new to this, but you’re doing a lot of significant upgrades to the machine. Is this a “new out the box” machine or an older machine restoration? Most of the videos on YouTube are new machine setup demos for newbies.  
> **username_4**: In either case, the “gross misalignment” I mentioned applies but it’s probably not too bad. Overall, the whole of the bed is too high. Mark the front of each adjustment wheel and then turn each two full turns to tighten the springs and lower the bed. You should need to dial in a negative Z-offset to get the nozzle on the bed at this point. Try Auto home and leveling.  
> **username_4**: If your machine is a straight Ender 3, did you remove the Z-limit switch and hard stop assembly when installing the CR Touch? You can’t really have both.  
> **username_4**: These are both methods of signaling (through change of state) what the Z-axis zero point is.  The advantage of the CR Touch is the repeatability of this signal relative to the bed.  I hope this works for you, it explains all symptoms you have reported so far.  
> **username_0**: I did remove the Z limit switch while installing and tried to lower the bed down, but the offset is still at zero. I´m going crazy now hahaha.  

---

### Answer by username_2 on 2023-01-25. Score: 0

Mine is doing the exact same thing on the latest Marlin Bug Fix, Ender 3 Pro, 4.2.7 board and CR Touch. On the 7th point it pushes super far into the bed and engages the springs. There must be a bug, I am going to compile the standard release and see if the same thing happens.

> **Comments:**
> **username_3**: Hi and welcome. This answer seems to be a cross between a "me too" type comment and a speculative fix (which, again, would serve better as a comment). Please [edit] and update your answer with a definitive solution as soon as you are able, otherwise this answer *may* be converted to a comment under the question... Also, please take the [tour].  

---

