I am reaching the end of my patience with my two ender 3 printers, hopefully some of you can help me diagnose it. Awful stringing/blobbing(see attached pictures). I am convinced the problem is either hardware or printer firmware, because I have old gcode files from 1+years ago that print awful too, and used to print great. The issue started sometime this summer. I say sometime because I did very little printing this summer, and now the quality is terrible. The printers are setup identical, mk8 hotends(not all metal). I tried new ptfe tubes, ends cut square and butted up snuggly against the nozzle and extruder ends, with no play, no noticeable improvement. Filament is definitely dry, it has spent many hours in a filament dryer at about 60°, pla by the way. I did one upgrade in the summer that I am suspecting is the issue. I installed skr mini E3 V3 boards and added a crtouch(those work awesome by the way!) Firmware is Marlin 2.0.9.3 The velocity settings are:
Mac X vel:500
Max Y Vel:500
Max Z Vel:10
Max E Vel:50
Min Velocity:0
Min Travel Vel:0
The acceleration settings are:
Accel:500
Retract Accel:1000
Travel Accel:500
Max X Accel:500
Max Y Accel:500
Maz Z Accel:100
Max E Accel:5000
XY Freq Limit:10
Min FR Factor: 5%
Junction Deviation:0.080
I have played with the accel, velocity, and junction dev settings, too, the above ones are the stock ones the firmware had. I have bumped extruder max velocity up to 100 just in case, it made no difference, as expected. Tried bumping retract accel up to 3000 in 3 steps on consecutive test prints, no improvement. Tried increasing max x/y accel up to 1500, no improvement. I turned down all the x/y accel settings to 250; still awful. I adjusted junction dev in a few steps on multiple test prints, first to 0.022, then 0.011, then to 0.110. Unsurprisingly, the 0.110 print was the worst, but all the others were pretty much identically bad. I’m pretty suspicious the junction dev setting(as opposed to classic jerk) is the root of the problem, as the old boards(4.2.7s) had classic jerk, I am pretty sure, although I never adjusted it, as the stock creality firmware and default accel/jerk settings always worked quite well for me. If anyone has any tips for me, that would be much appreciated. As I have never been able to manage to successfully compile my own firmware, if someone could could point me in the right direction to precompiled firmware for an SKR E3 V3 board with bltouch ABL enabled, junction dev disabled, and classic jerk enabled, I would love to try that to see if it solves my problem.
It looks like to me that you have a temperature problem.
When you changed your controller, where did you get the firmware and how are you confirming that the thermistor resistance at the nozzle is being correctly processed?
That’s what the thermistor info is on the printer, if that helps. I don’t have a multimeter, and can’t trust a cheap one, based on my experience at work with a cheap one. I don’t feel like shelling out the cash for a multimeter that costs over half what one of these printers is worth. I used my infrared heat gun to read the bed temperature on another printer of mine, and the heat gun seemed accurate, so I used it on the ender 3 and the bed looks right(not the issue source, I know), the hotend is harder to accurately read, being so small, but holding it up close, it appeared the temperature might be low, maybe 10 degrees low when set to 200C if I can trust the reading. Currently running the same gcode at 10 degrees higher temp print as a test. So far not looking promising.
I’ve worked with a variety of cheap (Home Depot $15) DMMs over the years and they should be more than accurate for checking the resistance of a thermistor.
As a quick test, does your bed and nozzle temperatures match when the printer has been idle for a while?
I am going to add a thought on a different tract. I would look at the nozzle. Worn out ones will string like crazy and blob too. It certainly could be temps but nozzles go, depending on materials quite fast.
On my 3 printers, all 6 thermistors are within degree of each other when at rest. Nozzles are all quite new as the worn nozzle idea occured to me too. Pretty much only black value pla through them. I can give the new nozzle idea a try though.
Well, I downloaded BTT’s official firmware for the board and did the test print again. Last time I tried their firmware the fans didn’t work for me, but they do now, not sure what I did wrong last time. Anyway, print was instantly a LOT better. Still not perfect, but I’m gonna try adjusting a few settings a little to improve it. Problem is, I don’t really like the official firmware layout compared to the one I had. Only two preheat presets, and the print from media option is pretty much at the bottom of the page. Maybe if I could persuade octoprint to talk to the printer I would be able to put up with it better.
Well, I finally got octoprint to talk to printer(an ongoing project till now). Printing seemed to work fairly well… Until I tried to level the bed. This official firmware, although it is supposed to support ABL, and does have it in the menu, most certainly does not actually have a working ABL system. If the hotend was not homed on the z axis, when I started an bed leveling routine, it would act as normal for the first bit, then when on the way down, about 4mm before the probe would touch the bed, it would stop moving, retract the probe, and the resulting error would require the printer’s power to be cycled. If the z axis was homed, and the hotend was far enough over the bed that the probe was too, the probe would tap the bed every couple seconds and remain frozen in that position. So I reinstalled the firmware I had before, and bed leveling issues went away completely. Of course, now I’m almost back to square one. As a test, I will do the same test print with all the accel, velocity, and junction settings the official firmware came with to see if that is a magic combination I somehow missed.
I have similar setup to you. Ender 3 with BTT skr mini E3 V3, but no ABL, and I have filament run out sensor. I had problems with the BTT V3 firmware until I compiled the bugfix version - the same version you are using now 2.0.9X. The other version is simply would not work for me with that board. This was several months ago, just after the board came out, so the firmware on GitHub might have been updated since then…
My problem was that the board would not even accept the firmware until I used the bug fix version, obviously a lot different then your problem, but after installing the bug fix version the printer worked flawlessly,
I tried again to compile my own firmware, and again I ran into the same issue, the PlatformIO extension will not successfully install in Visual Studio Code. I would like to compile my own firmware, as every thing I try seems to point to the issue being somehow firmware related, and I am running out of things to try. Below is the error I get trying to install the PlatformIO extension
Error: WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLCertVerificationError(1, ‘[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate in certificate chain (_ssl.c:1129)’))’: /simple/platformio/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLCertVerificationError(1, ‘[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate in certificate chain (_ssl.c:1129)’))’: /simple/platformio/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after c…
@MicroFarmModels
I cannot remember the specific error that I got in compiling my firmware, but I do remember it sounded a lot like what you just described regarding the platform I/O error. I could never get it to even compile for the skr V3, I thought it was because the board was brand new, so on a last desperate try, I used the “bug fix” version of the exact same firmware (2.0.9j and it compiled on my first try.
I even went back and compiled it again with some changes that I decided that I wanted(after using the printer for a while) and it worked, but the regular version still would not work.
I finally got a firmware that suited my purposes. I went to Ender 3 - SKR Mini E3 v3.0 - BLTouch - Marlin Firmware Service and registered and made a donation to get access to the precompiled firmware. The firmware I downloaded is 100% functional, and uses classic jerk, which I consider a perk. It also has a few other nice features the prior firmwares I used didn’t have. Print quality is up, although I will be doing some more testing and adjusting to see if I can improve it a little more.
