Cura 3.0.3 Temperatures all over the place

[dave_w 1]

I've attached a code snippet below generated by Cura 3.0.3 using two extruders/hot ends, the primary one (T0) with PETG at a print temp. of 245 and the second (T1) with PVA printing supports only at 220.

The first layer runs as expected with the two hot ends heating up to the set temperature right from the start but at each layer change Cura generates some weird temperature changes either side of it. Seemingly even while a hot end is in use.

T0 is being set to 220, 235 and 245 while T1 is being set to 205, 210 and 220 despite all my settings in the profile and the material for print and standby being the same.

It's driving me nuts as well as throwing temperature runaway errors occasionally as it drops the hot end by 15 degrees then heats it back up again while putting filament through it ! Having tweaked the firmware to allow more time and avoid the thermal runaway errors it's still doubling the print time sitting and waiting while the hotted it told to drop 15 degrees 30 seconds ago has to heat back up again !

 

G92 E0T1G92 E0M109 S210M104 T0 S235G1 F1200 E14G0 F7200 X91.5 Y74.804 Z18.8G0 X68.928 Y129.928G0 X69.14 Y130.139M104 S220;TYPE:SUPPORTG1 F900 E16G1 F600 X69.14 Y135.139 E16.1663G1 X66.984 Y135.139 E16.23801G1 X66.868 Y135.023 E16.24347G1 X66.868 Y130.255 E16.40205G1 X66.984 Y130.139 E16.40751G1 X69.14 Y130.139 E16.47922G1 F900 E14.47922G0 F7200 X68.875 Y130.139G0 X68.875 Y133.325G0 X68.979 Y133.325G1 F900 E16.47922G1 F600 X67.027 Y133.325 E16.54414G0 F7200 X66.984 Y130.139;TIME_ELAPSED:4463.505265;LAYER:93G0 X66.984 Y130.139 Z19;TYPE:SUPPORTG1 F3600 X68.785 Y130.139 E16.60404G1 X68.785 Y135.139 E16.77034G1 X66.984 Y135.139 E16.83024G1 X66.868 Y135.023 E16.8357G1 X66.868 Y130.255 E16.99428G1 X66.984 Y130.139 E16.99974G0 F7200 X67.027 Y133.325G1 F3600 X68.624 Y133.325 E17.05286M104 S205G1 F1200 E1.05286G92 E0T0G92 E0M109 S235M104 T1 S210G1 F1200 E12G0 F7200 X68.52 Y133.325 Z19G0 X68.524 Y135.296G0 X69.028 Y135.8G0 X95.657 Y135.8G0 X96.161 Y135.296G0 X96.161 Y71.982G0 X95.657 Y71.478G0 X91.114 Y68.804G0 X91.114 Y67.525G0 X91.9 Y66.739M104 S245;TYPE:WALL-INNERG1 F900 E16G1 F4500 X91.9 Y66.539 E16.00665G1 X94.1 Y66.539 E16.07982G1 X94.1 Y66.739 E16.08648G1 X91.9 Y66.739 E16.12306G0 F7200 X91.5 Y67.139G1 F4500 X91.5 Y66.139 E16.15632G1 X94.5 Y66.139 E16.2561G1 X94.5 Y67.139 E16.28936G1 X91.5 Y67.139 E16.38914G0 F7200 X91.1 Y67.539G1 F4500 X91.1 Y65.739 E16.44901G1 X94.9 Y65.739 E16.5754G1 X94.9 Y67.539 E16.63527G1 X91.1 Y67.539 E16.76166G0 F7200 X91.17 Y67.469G0 X94.83 Y67.469G0 X95.3 Y67.939;TYPE:WALL-OUTER

 

[rebekah_harper 60]

Would it be worth just trying default setting in cura to see what happens?

[tinkergnome 929]

T0 is being set to 220, 235 and 245 while T1 is being set to 205, 210 and 220 despite all my settings in the profile and the material for print and standby being the same.

That's the intended behavior for multi extrusion prints. There are more than this two temperature settings. It's an outstanding feature of Cura (IMHO). I suggest to enable all settings in the material section.

Which kind of printer do you use? Have you choosen the correct printer model in Cura? I ask, because there are additional settings in the printer profile (not visible at the user interface) that define the speed at which the nozzle heats up and cools down as well as the minimal time an extruder has to be inactive before the nozzle is cooled. It seems that you are using values that are not suitable for your printer?

[dave_w 1]

 

T0 is being set to 220, 235 and 245 while T1 is being set to 205, 210 and 220 despite all my settings in the profile and the material for print and standby being the same.

That's the intended behavior for multi extrusion prints. There are more than this two temperature settings. It's an outstanding feature of Cura (IMHO). I suggest to enable all settings in the material section.

Which kind of printer do you use? Have you choosen the correct printer model in Cura? I ask, because there are additional settings in the printer profile (not visible at the user interface) that define the speed at which the nozzle heats up and cools down as well as the minimal time an extruder has to be inactive before the nozzle is cooled. It seems that you are using values that are not suitable for your printer?

 

hmmmm, that's pretty rubbish then. I'll have a look at the printer definitions, my printer isn't listed as it's a CoreXY design that I scratch built so I just chose Custom FDM Printer.

Failing that I guess it's back to Slic3r as that sliced the same job without any issues. I remember now why I stopped using Cura last time when the developers started adding hidden "features" and removing basic functionality without telling anyone.

[dave_w 1]

Thanks for the suggestions so far.

Having looked through the printer definitions files and gone back to the "base" file that they all seem to inherit from, I can see the settings that may be causing my issues. I'll try creating my own machine type with all it's features and see if I can make the temperature changes a bit more sensible. It makes sense to cool the extruder when it's not in use and I guess the heat up speed/time means it can start the warmup process prior to the extruder being needed.

I'll make up a very simple test file with 2 small cubes being printed one from each extruder and see what effect changing the machine definition file has.

It seems I can also "fix" the minor irritation during the initial warmup too having spotted a comment in one of the files about Cura not inserting heat

up calls at the start if they are inserted in the start gcode for the machine. I can set it to do the bed levelling procedure without waiting for the extruders to warm up.

Am I right in assuming that I will need to restart Cura after making a change to a definition file or is it reloaded on the fly ?

[tinkergnome 929]

I'll try creating my own machine type with all it's features and see if I can make the temperature changes a bit more sensible.

Sounds like a good plan! I think these are the interesting parameters for this task:

• "machine_nozzle_heat_up_speed"
  
• "machine_nozzle_cool_down_speed"
  
• "machine_min_cool_heat_time_window"
  

Am I right in assuming that I will need to restart Cura after making a change to a definition file...

Yep, AFAIK all resource files are only interpreted during the start of Cura (at least it seems so...).

[rmi 4]

why are there 5 hotend temperature variables in cura is kinda the answer to your question.

Make initial printing temp, final printing temp and standby temperature visible in the material section to change the values.

[dave_w 1]

why are there 5 hotend temperature variables in cura is kinda the answer to your question.

Make initial printing temp, final printing temp and standby temperature visible in the material section to change the values.

I created a new custom machine definition but ran into all sorts of problems with that, still not sure why but I got it to the stage where I could choose my custom machine type but after that I couldn't get any further, having to delete the machine definition in terminal before Cura would successfully launch.

Anyway, I've not given up on it as I think there is room for more fine tuning available by using a custom machine... if only I can get it to work !

In the meantime, I made the setting suggested above visible and, finally I see where it was getting those strange temperatures from ! Having set them all to the same temperature and checked the resulting code all the temperature strangeness has gone

I will have a play with them further to fine tune them but so far it's looking good, thank you !

[DawsonJ 0]

I am having the same issue in 3.1. I do not follow the workflow outlined in the post to correct it. How do I go about making these setting visible? I am using an airwolf HD2x printer that only has one heater for a dual hot end. When it wants to cool one extruder and maintain temp on the other the 2 settings fight one another and the machine freezes. 

[dave_w 1]

4 hours ago, DawsonJ said:

I am having the same issue in 3.1. I do not follow the workflow outlined in the post to correct it. How do I go about making these setting visible? I am using an airwolf HD2x printer that only has one heater for a dual hot end. When it wants to cool one extruder and maintain temp on the other the 2 settings fight one another and the machine freezes. 

 I think you have two different issues. The first is that you need to make sure your printer's firmware is configured for a single nozzle, dual extruder, that way any instructions sent to the second heater are ignored by your printer and won't cause issues. If using Marlin firmware there is a single nozzle option you can turn on in configuration.h for cyclops type setups with a single nozzle/heater and multiple extruders.

 

Secondly, in Cura, click on the settings icon next to the title for the materials settings and turn on all the options for materials.There are 6 different temperature settings for materials and you should set them for both materials to be the same value for each option. 

[DawsonJ 0]

Dave_w 

Thank you for the response. Shortly before your response I found the additional 3 temp settings in Cura and was able to resolve the issue in the gCode. As for the settings in my firmware, it is an Airwolf HD2x printer and the Firmware is not open source. They want me to use their Apex software and will not adjust the firmware to work with Cura.