Print nozzle driving into the print bed

[GAP]

I had a failure while printing an object and noticed the mounting bracket on the BL Touch had been bent well out of 90 degrees it must have caught on something substantial but I'm not sure what, I am guessing it was most likely the print as there are signs that it had moved.
The print was full height at one end but at the other the lower levels curved up from the plate with loads of spaghetti underneath indicating an adhesion issue.
I straightened the bracket using a square and the sensor appeared to be working fine when sensing the build plate when I started a print, but the nozzle has driven into the build plate no filament flowed and there are brass marks on the build plate.
I think I may have to set up the printer again and replace the bracket and the sense pin or in the extreme the whole BL Touch.
I also think that build plate may need replacing.
Has anybody seen or heard of this sort of thing happening and offer any advice or direct me to somewhere that I may ask about this problem.

[drewzero1]

My Ender 3 v2 is just manually leveled but I had a similar problem when I didn't set the nozzle height properly and ended up leveling too high. The bed doesn't appear to be damaged, and the lack of flow is probably just due to the nozzle being pressed down so hard (mine did that too and was fine). From what little I know of the BL Touch it looks like an issue with the sensor alignment (such as a damaged bracket) might cause it to overcompensate, and if the bracket isn't straightened to exactly the right height, it won't be able to provide accurate feedback on the bed height.

You could try on Reddit, there are some active subs with people who have a lot more experience kitting out the Ender machines:
https://www.reddit.com/r/ender3v2/comme ... _problems/
* One of the pictures shows the sense pin getting caught off the edge of the bed, which could possibly bend the bracket in the way you describe.

[philipy]

I had something similar when I replaced my glass bed with an exact same item form the manufacturer and didn't do the full levelling and z offset height. I ended up with score marks in the dots pattern, exactly as your first picture, and a failed print, so I think there must have been a minute difference in thickness of the two glass plates. After resetting everything properly , i.e going right back to the initial set up for a new machine, it has since been fine although the beginning of the initial print after reset, the filament flow was weak and thin and didn't adhere properly, but I put that down to some slight damage/wear to the nozzle but it soon settled down.

I can't help with repairs to the BLT I'm afraid.

[GAP]

Further investigations have revealed that the bracket I straightened is not holding the sensor at right angles to the build plate and the probe actually has a slight bend in it (only noticeable when rolled across a flat surface).
I rang a supplier of replacement parts to get a new bracket and told me that what happened is not that rare, when I told him what had happened he said it would appear that the probe has caught on the print and tried to drag it across the bed but it was adhered to strongly hence the bent bracket and probe.
As the probe is adjustable by turning the small screw on the top of the body when I replace it I will have to do a complete bed level and Z offset adjustment.
I never would have thought that a print adhering to a bed would be strong enough to bend a mount, but it is alloy.
I think the replacement may be steel but I would think that would change the magnetic parts internally (will check with a magnet when they arrive).
The supplier said that the marks on the bed should not affect the print quality but if it does a new plate may be needed which will again necessitate a new tune.
In summary this is a lesson learned.
Thanks to all who offered suggestions/experiences it put me on the right track.

[3 minutes of fame]

It's just the Z height that needs recalibration. If the bed trolley is bent, then replace it, but the glass plate will tend to flatten out the build plate to within the tolerance required by the probe and firmware on the printer to correct.

Just checking you are running the right firmware and g-code to correctly capture and store the bed map? Also worth checking that the Z probe has not been damaged if it bashed into the plate.

[GAP]

I am running the Jyers software which has a store mesh to EEPROM function.
The plate looks level what is the bed trolley?
I am replacing the probe and the bracket.

[3 minutes of fame]

Ahh, ok, I thought you were concerned about the build plate not being flat. Just me not reading your post correctly.

In which case, I would not worry about the bracket being completely aligned, just repair or replace the probe and reset the Z height.

I use a glass bed, sprayed every few prints with hair spray. If a part is then difficult to remove, I just submerge the plate in cold soapy water and the parts just release. I never have adhesion problems with this technique.

As you surmised, the problem was due to the part warping or failing to properly adhere, so it then caught on the sensor. Improving bed adhesion through Z height adjustment and perhaps using hair spray should fix the problem.

The good news is that with the BLTOUCH, you are simply setting the relative height between the sensor and the nozzle, so you can change the build plate and the sensor will compensate for the revised zero position. For some materials, I swap out the glass bed for a textured mat. No recalibration needed, the printer will just adapt to the new Z height.

[GAP]

I am about to attempt to repair my Ender 3V2 printer with the bent BL Touch bracket.
I have had a look at it and it looks like just a replacement of the bracket and the probe are required.
I have the Jyers 4.2.2 3x3 firmware installed at the moment which sets up the bed mesh probing before each print at 9 points across the bed.
I am thinking up replacing it with the Jyers 4.2.2 5x5 firmware which probes 25 pints before a print.
I am thinking that the extra probe points will give a better first layer as imperfections in the build plate will be better detected.
Except for the extra time needed before a print is there anything else that people have had; experience with or knowledge of, using this firmware?

[philipy]

I have the Jyers 4.2.2 3x3 firmware installed at the moment which sets up the bed mesh probing before each print at 9 points across the bed.
I am thinking up replacing it with the Jyers 4.2.2 5x5 firmware which probes 25 pints before a print.

I have no knowedge of those firmwares you have mentioned, but I do have a Kywoo printer which probes 36(!) points and the time that takes drives me nuts. In many cases it takes longer to heat the m/c and do 36 points than the actual print time and if I want to do several prints one after the other, it goes through the complete rigmarole each time. I also have a Creality CR20 Pro which does just the 9 points, and from a levelling/print POV I see no real difference between the two m/c. So if your reason for changing firmware is simply to get more touches, I'd say leave well alone, myself

[GAP]

Thanks Philip,
From my research I found that the "Jyers" firmware is a variation of the "Marlin" software Creality uses, its written by a bloke called Jyers and offers more features than Marlin.
https://all3dp.com/2/jyers-firmware-ender-3-v2/
If you are using Creality Slicer (its basically Cura tweeked and re-badged) there is an add on that puts Z offset into the menu.
It was working fine till the bracket got bent so I'll follow your advice.
If "it ain't broke, don't fix it" applies here I think

[philipy]

[3 minutes of fame]

Nothing wrong with the Jyers firmware. I use a similar build, just customised a little to better suit my hybrid machine.

25 probe points take about 75 seconds to probe, and then the machine starts automatically. Yes, more points means a better map, and certainly its reduced recalibration of the bed to pretty much an annual task. Silicone bed supports in place of the springs certainly helps with that one.

[GAP]

Update of yesterday's efforts;
I had to resort to going right back to the original firmware to be able to get the bed level manually.
When I tried to set the Z offset using the probe the nozzle would home at about 10mm+ above the bed and the Z offset control did not have the range to get it anywhere near close to give a good print.
I did notice that the new probe pin seems to hit the bed at an angle less that 90 degrees, there is a fine crack in one of the mounting holes on the BL Touch so maybe that is causing that issue.
I may have to replace the whole probe assembly to get back to where I was before this happened.
I was able to remove the brass marks on the plate because it was actually embedded in filament and not on the glass but during one attempt the nozzle was driven hard into the plate and dragged across it leaving score marks. A new pate may be needed in the future.
In summary I think my next step is to flash new "Jyers" firmware and try again if that does not work then I'll replace the probe and the nozzle, as it may be damaged by being dragged across the plate.
If all that fails I will take up the wife's suggestion and "just by a new one if its causing all this trouble" but that will be the last resort.

[GAP]

Nothing wrong with the Jyers firmware. I use a similar build, just customised a little to better suit my hybrid machine.

25 probe points take about 75 seconds to probe, and then the machine starts automatically. Yes, more points means a better map, and certainly its reduced recalibration of the bed to pretty much an annual task. Silicone bed supports in place of the springs certainly helps with that one.

Where did you get the silicone bed supports from?
Just had a quick look on the net about how they work and I'm impressed with them.

75 seconds doesn't seem like a long time especially when some of my prints are over 10 hours the extra time might be worth it.
More thought required .

[philipy]

25 probe points take about 75 seconds to probe, and then the machine starts automatically.

Not arguing, but 3 seconds per probe seems very fast? I've never timed my Kywoo before but I know it takes a long time, so have just timed it and it actually takes 6 min 57 seconds to do the 36 probes ie 12 seconds each. So, I then checked my Creality CR20 Pro and that takes 9 seconds each to probe 9 points.

So your Jyers firmware must turbocharge the BLT! Other than that, what other advatnages does it have over the standard Creality firmware?

[GAP]

25 probe points take about 75 seconds to probe, and then the machine starts automatically.

Not arguing, but 3 seconds per probe seems very fast? I've never timed my Kywoo before but I know it takes a long time, so have just timed it and it actually takes 6 min 57 seconds to do the 36 probes ie 12 seconds each. So, I then checked my Creality CR20 Pro and that takes 9 seconds each to probe 9 points.

So your Jyers firmware must turbocharge the BLT! Other than that, what other advatnages does it have over the standard Creality firmware?

When I installed my BL Touch the instructions I followed said to install Jyers, from what I have read it was written to overcome the short coming of the supplied Ender3 V2 firmware.
https://www.reddit.com/r/ender3v2/comme ... ifference/
Creality now have a version of "Marlin" for BL Touch on the Ender3 V2.

This all may be fairly moot if I cannot get my Ender3 V2 running as it did (I am giving it another go over the weekend) because I can get an Ender3 V3SE with all the features that are add-ons for the V2 at a cost of $350 from a local store, if I do buy it I will then probably sell the V2.

One of the features that impresses me is that besides having Creality's own touch probe it includes a new strain gauge sensor on the print bed that allows the printer to set the Z offset automatically.
This is done by using the strain gauge to detect when the nozzle touches the bed.
On older Creality 3D printers, you had to manually configure a Z offset value using the controller, to tell the printer exactly how much distance there was between the tip of the probe and the nozzle itself.

[3 minutes of fame]

I gather that with most probes, you can decide to probe once or twice. Mine is set to single probe, as that seems to provide sufficient accuracy for excellent adhesion, and good layer finish

[GAP]

After a lot of work I have my Ender3 V2 working again.
I replaced the bent bracket and the probe, the BL Touch looks a little of square but it doesn't seem to affect the probing.
I went back to square 1 and loaded the original firmware and without the probe being in play I levelled the bed.
I started by using a "T" level and a bullseye level to roughly get the bed level, then proceeded to level the bed using the paper method.
This took a rather long time until I finally worked out that no matter how careful I was that when I moved the print head I actually put downward pressure on the Z axis and changing it's the height so I was forever readjusting the knobs.
Reading many, many articles on levelling and watching hours of YouTube videos, I found a method that uses the printer controls to move the print head into the 4 corners to use the paper method that removes the risk of shifting the Z axis.
A quick level up and then a Z offset adjustment I tried a test print, the nozzle hit the print in a couple of places and in a others all I got was a blob of plastic.
Watching the print a couple of times with similar results I found the nozzle was to close to the bed so while it was printing I used "live adjustment" till I got a fairly good print.
I then loaded an stl file and printed it and it came out very good, bit of stringing but as I used the Creality PLA that came with the printer all in all it was a good result.
I had just finished the print when the phone rang and it was Jaycar telling me that the Ender3 V3 Se that I ordered had arrived.
So I now have an V2 working and a V3 waiting to be assembled.
The ender3 V3 assembles in 20 minutes and solved the bed levelling issues once and for all and is comparatively faster than the V2 according the numerous review I read (Creality lists some outstanding specs for speed which most reviewers say the printer will not achieve but is an improvement).
https://worldoflilliputs.com/ender-3-v3 ... -3-v2-neo/
I have reconsidered selling the V2 but for a while will now use it as a experimental machine with Octoprint being the first project to be attempted.I might upgrade it to twin Z axis drives in the future.
The new printer is not recognised in Creality slicer so I will most likely use Cura which after all that is where Creality got there source so that is anothe learnig curve but I do have ahead start as I found a list of settings for PLA while looking at the net.

[drewzero1]

Sounds like a pretty thorough solution. Having a new machine can definitely take some pressure off the old one, and open the door for more experimentation. I've been really enjoying the combo of Cura and Octoprint-- Octoprint in particular has changed the way I use my printer. It's been great to have a video feed and a 'stop' button from anywhere in the house!

[GAP]

Sounds like a pretty thorough solution. Having a new machine can definitely take some pressure off the old one, and open the door for more experimentation. I've been really enjoying the combo of Cura and Octoprint-- Octoprint in particular has changed the way I use my printer. It's been great to have a video feed and a 'stop' button from anywhere in the house!

I'm using an Ethernet cable, primarily it is hopefully going to replace using an SD card every time I want to load a print.
There is are upgrades available I'm looking at the dual Z axis and the direct drive extruder for the future.