There seems to be one simple rule in 3D-Printing - at least in my case: If you have solved one problem - the next one is just around the corner. I'm so sorry to ask all these dumb questions, but I have to. At the moment, when I try to print via OctoPrint, my printer does not start the print after the bed and the hotend has reached it's target temperature. There is no error or something else which could help. The printer just keeps holding the temperature between 197° and 206° but nothing more is happening. The display keeps displaying "Heating..." The only thing I changed since the last successful print-start was to upgrade to a new firmware. Did I miss something I have to adapt which could explain this issue? Thanks in advance for your support - again!
Hi, Looks like you could do with a PID autotune | http://reprap.org/wiki/PID_Tuning That (EDIT) Might fix you problem but it will stabilise the temperature of the hotend and stop the variation.
your temp has to be stable before the print will start 1 0r 2 degrees fluctuation maximum for 10 seconds, have you done a pid autotune ?
That is not a dumb question, and points out an important thing to know, which as @corey points out above you need a stable temperature for 10 seconds. Pid tuning will likely fix this, however you can also cause this with fan settings later, etc So if you don't see a nice stable graph, your print likely will sit at heating forever...
Thanks so much @Greg Holloway , @corey , @Henry feldman !! Looks like this solved the issue! You guys are all great!! So who ever has this issue as well: Open OctoPrint Make sure OctoPrint is connected to the printer Goto Terminal (within OctoPrint) Send the command: M303 E0 S200 C8 (this will start the PID Autotune (heating E0 to a Temp of 200° 8 times) Wait until you see: PID Autotune finished (with some values attached (Kp, Ki, Kd)) (will take about 5mins) Send the command: M301 P19.95 I1.23 D80.89 (replace the values with your results!!) to store the settings in the current configuration Send the command: M500 (without any value) to store the settings to the permannet EEPROM After that, you should have a much more stable target temperature. Be happy and print along! BEFORE and AFTER comparison:
This worked good for me... one question for us with dual. I got different values for E0 and E1. Is there any way to store it per extruder or should I choose one or take the average?
I gather newer Marlin firmware can store per extruder PIDs although I don't know what version / branch etc
See the PID Tuning post for instructions down this particular rabbit hole. https://forum.e3d-online.com/index.php?threads/pid-tuning.731/page-2#post-15831 Also, note that Octoprint PIDTune has now been "fixed" to deal with two extruders. In my case the issue was a too small heater (size not wattage) that I had to shim out with a piece of aluminium foil. There is now a slight difference between E0 and E1 on my 1.0 Dual, most likely due to the Z axis sensor behind the E0 extruder. Having tuned the the PID's (X, Y - middle of the bed, Z about 3mm), Heated bed on (if using it and part cooling fans on). In my case this gave me some lovely flat temperature lines.
That's strange. The auto PID does actually work, but I have to do it again and again after every 3rd print or so. What could this cause?
Did you store the settings? Doing it no matter how (LCD, OctoPrint plugin, manually terminal command) and set the values they are not persistent only up until a reset... LCD does actually set the values itself but you gotta store...
M500 does not take any parameters, it just writes all actual parameters to EEPROM. You have to issue M301 P* I* D* first and then M500.
Oh, okay.. Good to know.. Thanks for the help, sounds like this could cause the issue. The terminal gave back an okay though..
Aye that way round you are just saving the settings before you change them so they will be lost on a reset. M301 command first and then just M500 on it's own when you are done (btw getting the octoprintPID tune plugin makes this a ton easier)
