This may be a little long but here it goes.
I got a Ender 3 V2 for Christmas. I have yet to get a print out of it. Many emails back and forth with Creality support and the glass bed and the controller board have been replaced. Still cannot print.
Here is the issue:
Leveling the bed at all 4 corners using a .104 feeler gauge with bed heated up, nozzle will drag on the bed in the center area. Adjusting the Z offset in the center results in filament not sticking outside the center area.
Leveling the board normally and trying a 1 layer test print results in the nozzle dragging in the center and either causing the extruder to click because nothing can come out or it will ooze out and become a clump on the hot end which it will then proceed to wipe the bed clean and everything gets stuck to the hot end. I have blown through 4 spools of filament spent countless late nights and entire weekends to get this thing to print and it just wont. Creality seems to want to fire the parts cannon at it rather than replace it.
I am pretty sure that the top part of the printer (frame) is the issue.
Things I suspect may be the issue:
Rollers are not concentric.
X axis channel is not machined straight
X Axis beam is warped/bent
Z Axis stepper has got a case of the jitters
I have completely disassembled and reassembled this printer 5 times. Creality actually sent me a 4.2.7 board which is even more quiet than the 4.22 board. I have not seen any negative reviews on this printer and can only assume I got a defective / lemon.
I have even tried custom firmware sent to me by Creality.
I just downloaded the bugfix release of the latest marlin 2.0.x and installed that . . . No Dice!
If anyone has any ideas or has encountered this issue I would gladly like to hear from you!
Could this be your problem?
Have you checked the flatness of the heated printbed? Put the edge of a good quality metal ruler across the printbed & shine a light from behind. Look at the joint where the ruler meets the printbed to check if you can see any more light coming through 1 area than the others. In this case, I would be looking to see if light shows through at the edges of the bed while none shows through at the center. Since you may be dealing with a high-center problem, I would see if the ruler can rock back & forth from edge to edge when it’s placed across the midline of the bed.
The bed has been replaced already. Tested with a straight edge and a .0025 feeler gauge. Glass is most definitely flat. On the original Glass I was able to get feeler gage in in the center but according to Creality it was still within spec.
Hmmm. Perhaps it’s time to check the distance from the gantry to the printbed & the straigtness of the X carriage extrusion.
1 thing you can try is to turn the printer off, then manually move the bed, X, & Z axes to put the nozzle is in center of the bed. Ensure the nozzle just clears your .0025 feeler guage. Then, move the printhead to the left edge of the bed & check the clearance, then the right edge & repeat. This should tell you whether the issue is related to the X carriage. If the clearance is not the same at all 3 points I would measure the distance from the X carriage extrusion to the printbed. You could also try putting your straignt edge on the X carriage to see if it is actually flat.
I don’t need to use a feeler gauge. You can see it. If i set the gap to 1 mm on all 4 corners the nozzle will hit the center. I really don’t want to disassemble the printer again unless it is to replace it.
If your sure that the X gantry is parallel to the frame, not the bed, then I would try removing the glass plate and placing a piece of painters tape down both sides of the bed… Replace the glass bed and see what your get.
OK, but that doesn’t answer the last point of my post: i.e. is the X axis extrusion flat & evenly parallel to the printbed? In your case, the question is whether the X axis extrusion is depressed in the middle, so it actually forms a shallow valley.
I am new to this but I had some similar problems setting up an Ender5 Pro (I know they are built differently but this should be relevant) and I learned several thing that might help you. I first tried the solution that Dr Vax uses in one of his videos of the paper between the build plate and the build mat but the but after adding 2 layers of paper it still was not totally flat. I was not satisfied with that and I discovered after some work what the problem was. I would first verify that the build plate is part of the problem. Take a ruler (preferably metal) that is approximately the length of the build plate and lay it across the build plate in several location and orientations and check to see if there are any gaps where you can see light. This is technique is also form the Dr Vax video referenced above. If its warped it should be pretty obvious. I would watch the video reference above but I discovered a different issue and fix.
The root cause of the problem for me was that the Z axis home switch was set way way to low. This caused me to preload the plate with with a lot of spring tension. All the springs were probably 3/4 the way compressed. I thought this was a good thing at the time because it made the spring stiffer and the weight of the plastic would not cause it to change as easy when printing. After much experimenting I discovered that the excess spring tension was warping the plate. Raise the Z axis a several inches to get it out of the way and removed all the spring tension then use the ruler method form above to check if the problem is better. In my case it removed all the warp. Move the X and Y axis to the home position by hand then. just place a piece of paper on the build mat to act as a spacer and bring down the z axis by hand till the tension on the paper is correct, set the z-height stop adjustment till the limit switch is engaged. I would then turn on the machine and have it Home just to make sure that that the stop switch is set correctly. If the paper is a tight I would probably just use the bed leveling adjust to set it then. Turn the machine back off. Move the head across the biuld plate in the X direction checking the gap as you go and make adjustments as you go. Then move the plate fully by hand in the Y direction checking and adjusting as you go. Check and adjust back across in the x direction. Then check the middle. It should hopefully be right on or to the point that the method that Dr Vax uses in the episode will work. You should then turn on the machine move to home then using the panel move through all the location using the paper to check as it moves making what at this point should be very minor tweaks.
@LDMaker, it’s very to find out that the springs can actually warp the bed. I would never have thought it possible. Thanks for sharing.
I will differ from your recommendations in 1 respect: I would not set the Z Limit Switch height as you have done. I feel it increases the risk of the nozzle getting buried in the bed. I would set the limit switch a few millimeters higher than what you have done & then use a negative Z Offset value to make sure the nozzle is lowered to the correct height during printing.
I don’t have a Z axis stop as I have installed a BL Touch. I thought this would fix it for sure.
I cut a couple pieces of 2x4 up and placed them on the bed. I then used calipers to measure from the top of the X Axis beam to the bed.
Measuring from left to right
Left Side was 68.64mm
Center was 68.46mm
Right Side was 68.43mm
there is a difference of .21mm from left to right.
Just to clarify Creality has sent several videos and instructions on how to test the bed tolerances and determined that it is within spec.
Aluminum bed is straight. Checked with a straight edge and a .0025 feeler gauge
Original Glass bed was not straight but was within tolerance. it was replaced. New glass bed is perfectly straight
Then they sent a new controller board. Original controller board was a 4.2.2. New controller is a 4.2.7.
I have used the stock firmware for the 4.2.2 board. I have also tried a custom version that Creality sent me.
I have also tried with the stock firmware on the 4.2.7 board. I am currently running marlin 2.0.x bugfix and all give the same result.
I think .0025 inches is a little close. I just use paper. It’s about .1 mm or .004" and its about right. What filament are you trying to print? What what temp are you using? Run a PID auto tune and make sure that your temp and nozzle is accurate. Check to make sure your are extruding the correct amount. There are video to explain how to do all of this.
I don’t recall you mentioning a BL Touch before. That changes things. It is possible you’re having issues because the BL Touch bed map is incorrect. It could also be that your printer is having signal issues. Others have posted that they had BL Touch issues until they installed a shielding sheath over the cables from the BL Touch sensor to the control board.
I presume you’ve run G29 commands multiple times?
To dispel the BL Touch issues, it does the same thing with or without it. Hence why I didn’t mention it.
@LDMaker the .0025 is to check for straightness of the bed with a straight edge, not the gap between the nozzle and the bed.
OK, just to clarify, when you move the printhead around the printbed by hand (i.e: with no power on), does it still hit the bed in the middle & not in the corners?
Did you change the firmware to support the BLtouch? For me the Creality firmware for the BLT didn’t work and I used the firmware froom Smith3D
Gramps, I did the same. used the smith 3d firmware. however I’m probably going to go to silicon bushings to keep my print bed flat…or lock nuts…