We need to know the printers current e-step value, and a physical steps/mm value (what the printer is actually spitting out). This calibration is especially important if you’re changing the extruder from one that uses gears like the Titan Extruder found on Anycubic printers to a spindle drive.
Determining your current steps/mm value for your 3D printer
Connect PC to USB port on printer. Download and run “Pronterface”. Once connected, In the Command Window enter M503 (report settings)
Look for a line starting with M92 and at the end you’ll see your current e-step (steps/mm) value
example. echo: M92 X80.00 Y100.00 Z400.00 E405.00
Determining the physical steps/mm value for your 3D printer
Heat the extruder on your printer.
Using calipers and a sharpie, place a mark on your filament at 120mm from the entry hole to your extruder.
In pronterface, Send: G1 E100 F100
This tells the printer to slowly extrude 100mm of filament
Determining the correct steps/mm value for calibrating your 3D printer’s extruder
Measuring the distance from the extruder to the mark on the filament, then subtracting that value from 120:
120 – [length from extruder to mark] = [actual length extruded]
Next, we need to know how many steps the extruder took to extrude that much filament. We can determine this value by multiplying the steps/mm value by the length we should have extruded, in this case 100 mm:
[steps/mm value] x 100 = [steps taken]
Using this, we can obtain the physical, correct steps/mm value by dividing by the length extruded:
I’ve created a list of list of possible issues that can cause the Anycubic MEGA S and Chiron to randomly stop during printing.
Corrupted SD card file system
Failing SD card reader board
Symptoms often include:
A random (heartbreaking) print fail.
Your printer will sound it’s power up chime. (Then you sing a four letter aria that would make Pavarotti proud.)
When attempting to manually move the print head or build plate you get an error message, “The Machine is running, please try again later.”
An inevitable power cycle to regain gantry control to unbury the print head from the 90% completed garden gnome sized baby yoda you were printing for your grandma.
You’ll notice most of the connectors on your Anycubic printer have blobs of hot glue on them.. this struck me as odd until I watched this YouTube video about similar random print fails. The hot glue acts as a lock minimizing the chance of connector back out. I was really surprised to see the temp sensor for the heated bed glued to the mother board. If you’ve purchased your Chiron recently, you’ll also see the hot end data/power cable is cinched to the cage using a zip tie locking it in place.
Loose connector resolution:
Pretty straight forward. You simply go connector to connector checking to see if they’re seated and tight. If you’re feeling frisky you can add reinforcing hot glue.
Thermistors are used in the hot bed and heater block as part of the feedback loop that keeps the printer on task. If the thermistor fails, gives bad data, or gets disconnected the print head will halt immediately and the hot end cooling fan will kick on full speed. I think it does that so it can’t hear me cussing. “T0 sensor abnormal”
Hot bed thermistor Resolution:
To test if your hot bed thermistor is causing problems, you can turn off the heated bed in your slicer and run a few test prints. If the intermittent fail goes away, you’ve got your culprit (and hopefully a bunch of double sided tape). In the case of my Mega S, my print would fail at 3 hrs out (randomly), then 1 hour, then during the skirt print, then it just wouldn’t start. Anycubic customer support recommended turning off the hot bed and sure enough it printed to completion. Anycubic will work with you to get the bed replaced or you can learn more about replacing the hotbed thermistor here: https://youtu.be/UEfxie6aVtw
Heater block thermistor resolution:
The easiest solution is to install the spare hot end that came with your Anycubic.
Heater thermistor combos are not that expensive if you’re comfortable splicing wiring. 24V 100KΩ NTC3950 Thermistor & Ceramic Cartridge Heater 12V 40W. Consider using thermal paste when installing your thermistor and ceramic heater cartridge.
Corrupted SD card file system:
The file system on your SD card has become corrupt or you have a memory failure going on.
Corrupted SD card file system resolution:
Reformat your SD card using fat32 for the file system or try a new SD Card.
Failing SD card reader board:
So it’s possible (rare) the SD card reader daughter board is acting up and causing intermittent failures.
Failing SD card reader board resolution:
Remove the SD card from your printer and plug a USB cable from your Anycubic to your PC to run the print directly from your slicer. (At the time of this writing I was literally 15min from completion on a 7hr Cura/PC to Chiron test print (1 of 3) to determine if my SD card reader is flaking out. Just one of the reasons I decided to make this list.)
In my experience broken wiring normally affects the hot bed where the power and thermistor wiring come off the bed and begin running down the Chiron frame. They really need a cable plug assembly mounted to the bed that reduces stress on this cable and allows you to simply unplug the connector from the bed to replace or service it. You could build it into the bed clamp assembly for added strength.
Broken wiring resolution:
Shoot a pic to Anycubic customer support and they’ll work with you on getting it replaced. OR if your handy with a soldering iron and heat shrink tubing, the fix is straight forward.