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Ender 3 MAX with BL Touch


Jslwelch
(@jslwelch)
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The way I set the Z axis offset was to print a large first layer and adjust the z axis on the fly.  That worked for me!

However, I have an observation and a question.  Let's start with defining the hardware. 4.2.7 mainboard, 1.0.1.6 BL Touch firmware for Ender 3 Max.

While trying to find a way to set the esteps after figuring out that the buggy 1.0.1.6 firmware does not do filament advance to a specified value such as 100mm, i saw that Pronterface could be used to control aspects of the printer.  So, let's check it out.  It allowed me to send a G code command (G1 E100 F100) directly to the 3 Max to extrude the 100 mm filament.  Situation solved and got the correct esteps set. (For me was 99.)

I noticed after running a bed level test directly from the printer, that the results came up in Pronterface!  Goody...   Let's run a test and see how close to level I could adjust the bed!

Here are the results:

All tests done with bed at 60C

First Test:
0 1 2
0 +0.043 -0.037 +0.063
1 +0.094 +0.015 +0.136
2 +0.039 +0.031 +0.183

adjust back r/h side, 1/4 turn bed up

Second Test:
0 1 2
0 -0.071 -0.148 -0.056
1 +0.018 -0.039 +0.087
2 +0.015 +0.015 +0.208

no adjustment

Third Test:
0 1 2
0 -0.002 -0.088 -0.003
1 +0.095 +0.012 +0.136
2 +0.081 +0.083 +0.256

adjust back r/h side, 1/2 turn bed down

Fourth Test:
0 1 2
0 +0.038 -0.089 -0.050
1 -0.699 -0.061 -0.001
2 +0.000 -0.072 +0.021
No change, repeat fourth test....

Fifth Test:
0 1 2
0 +0.042 -0.095 -0.062
1 +0.073 -0.054 -0.020
2 +0.012 -0.079 +0.006
No change, repeat fifth test....

Sixth Test:
0 1 2
0 +0.051 -0.093 -0.061
1 +0.077 -0.058 -0.019
2 -0.046 -0.077 +0.011

 

So the question:  Do I have bad bed level sensor?  Nothing is really repeatable! Second and third test, and fourth, fifth, and sixth tests should be mirror images, and they are not.


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kevin
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@jslwelch That was strange! Even you did not adjust the bed, the measured result is different from the last test?


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Jslwelch
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@kevin  That's correct.  Second and third test, and fourth, fifth, and sixth tests should be mirror images, and they are not.

The only way you would know if yours worked properly, would be to repeat the test on your system, and see if you get similar results.

This post was modified 8 months ago by Jslwelch

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kevin
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@jslwelch I got similar almost the same results if I did not change anything, just test it again. Do you have any idea what is happened of yours?  Firmware issues? 


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Jslwelch
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@kevin  I'm not positive what the issue is.

Let's list the possibilities:

1) BLTouch device 3.1

2) Firmware

3) Mainboard 4.2.7

We know the firmware is buggy and not what I would call highly reliable (1.0.1.6).  But I've also noticed that sporadically the 9 point sensor test will fail in some random position on my printer and that definitely makes me think the sensor is bad.  I don't think it is the mainboard as it seems to do nothing wierd.

I suppose the next logical test would be to test directly from Pronterface and see if the same results occur.

After that maybe do some calculations to see EXACTLY what the differences are between the various no change test positions to see if I can live with the variances.

BTW...  I did manage to get hold of the 1.0.1.8 firmware the printer was equipped with when it shipped to me, which is supposedly not for BLTouch.


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florianrau
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Hi,

have you been able to resolve the issue? I'm facing exactly the same problem with unreproducible measurements and random failing tests.

 

I'm using a BLTouch 3.1 with Mainboard 4.2.2 and was using the BLTouch Firmware from the Marlin 2.0 Thread as well as the original BL Touch Firmware by Creality.

 

Regards,
Florian


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kevin
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@florianrau Hi, Florian. Can you print things successfully? It is normal that you can NOT get the total same data. Even if nothing changes! 

What you see is nothing moving, but the accuracy of BL Touch itself, and the vibration of the hotbed during the test will make the data different. 

You have to understand that BL-touch measures the whole bed leveling, instead of some points' height.


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florianrau
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Hi,

I have some really weird behavior. Around 10% of the probing fails, sometimes I see the probe is working, but the nozzle crashes into the bed,although the Z offset was set several times..

I have ordered now a second one, but it only got a little bit better.

Regards,
Florian


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kevin
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@florianrau I do not understand if the probe is working, why the nozzle will crash into the bed. 

Are you sure that you take the Z-end switch off? Because when the probe always touches the bed before the nozzle does. When the probe touches the bed, the nozzle will stop and thinks that the height is Z=0.


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florianrau
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Hi,

it looks like the first probe was definitely broken and was only working sometimes. The Z-end switch was definitely disconnected

With the new one, at least I have no more crashes and after using a self-built 2.0.8 firmware image everything works now as expected.

So all in all I assume it was a combination of the firmware (I've tried the original BL Touch-enabled firmware and the marlin 2.x build from this forum) and the broken bl touch.

Regards,
Florian


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kevin
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@florianrau Hi Florian. good to hear you fixed it. Can you build firmware by yourself? ? 


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1Slowrolla
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New too 3d printing so noob questions. I purchased an Ender 3 Max and now trying to install the BL Touch but cannot seem to find any videos on step by step instructions to my install.


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kevin
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@1slowrolla The video is based on Ender3v2, you can refer to this because the mainboards are both V4.2.2 for Ender3v2 and Ender3 Max.

  

But be careful it is different firmware for Ender3 Max.


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