How Hot is Too Hot? Temp Tower
Updated: Sep 18, 2021
When you get your 3D Printer assembled, bed leveled, e-steps, and flow rate set (check here for those steps), you can usually start printing with few issues.
It is good to run some test prints to do some further dialing in your printer and slicer settings. These additional checks help find problems before they arise or may help you if you start seeing quality issues in your prints. They can also give you peace of mind that everything is working correctly.
TIP Make small adjustments and only adjust one thing at a time and re-test. Write down what you are printing as your test, the results you are getting, and even take a picture of the completed test to add to it. Having a log to check back on when things go wrong is helpful.
When you start, you will need to know what temperature to set your hot end. In most cases, you can get away with somewhere in the maker's range on the label. If you want to be sure what to dial in, print a Temp Tower.
TIP Some Temp Towers found on thingiverse and other sites will offer both the file itself and the gcode. I strongly suggest using the file and slicing the file in your slicer (such as Cura). Each machine can be different, and you run the risk of driving your nozzle into your bed or having some other issues that leave you scratching your head.
Hot End Too Hot
If the hot end is too hot, your filament will melt more than needed, which will lead to stringing, oozing, and blobs. You can also end up with burned/discolored filament on your print.
Elephants foot is another issue with printing too hot. Your first layers are so soft that as additional layers are added, it smooshes them down, squishing out those first layers. This can also cause the print to stick too much to your build plate.
Hot End Too Cold
If the hot end is too cold, it can result in your extruder skipping, making a clicking sound.
It can also cause your layers to separate since they are not hot enough to melt together.
Bed Too Cold
If the print bed is too cold, it can result in your prints not sticking correctly. Clean the bed, then raise your bed temp by 5 degrees and try again.
Warping is when the corners of the print start to peel off the build plate. Warping can be confused with elephants foot. Warping is most likely caused by drafts around your printer, fans running, etc. The printer needs to have a pretty stable print environment. Close off vents that are causing drafts, don't run fans pointing at the printer, and you may need to look into enclosures.
Once you have the Temp Tower file and open it in your slicer, you have to tell the slicer to change the temperature at different layer heights. I am using Cura 4.7.0.
NOTE: I am using CHEP Cura Profiles for my printer to test.
The Printing Temperature is the temperature at the bottom. With the Temp Tower I am using above, that is 240
Set Infill % to the recommended infill from the creator of your Temp Tower. Check the ReadMe file or the thingiverse comments. I am using 10%
Go to Extensions > Post Processing > Modify G-Code
In the Add a script drop-down, choose ChangeAtZ
*If this script is not available, go to the Marketplace and install it
The Trigger should be set to Height
Your ReadMe file should tell you when to adjust the temperature. For the file I am using, it is every 5mm
Apply To should be Target Layer + Subsequent Layers
Check Change Extruder 1 Temp
Change the temp to the next target temp on the tower. In my case, that is 235
Click on Add a script and choose ChangeatZ again
You need to update the Change Height to 10
Check the box for Change Extruder 1 Temp
Update the temperature to the next test temp, which for me is 230
Repeat these steps making sure to update the Change Height and Extruder 1 Temp until you have the script complete
Click on Close
You will notice a script icon next to the Slice button. The script icon reminds you that you have a script that will be processed and included in the gcode when clicking on Slice.
TIP The script will remain for every print after this. Once you have the Temp Tower done, I suggest removing the scripts by clicking on this button and then clicking on the x's to remove each line of the script. Otherwise, the script will be applied to all future prints.
All that is left is to Slice your file and print it out!
Here is what my completed Temp Tower looks like using eSun Cool White PLA+
You can see from this photo that there was burned filament at the higher temps and you can't read the numbers very well at 240, 235 and 240. The bridging is also pretty horrible at the higher temps.
Based on this, I would choose anything between 205 and 210 for this filament.
Here is a slightly better view of the bridging. The top cooler layers didn't hold up as well, but you can tell at 205 and 210, the bridging looks better.
Just a reminder to remove the script before your next print!
Thanks for hanging out this long! I hope this article was useful for you and helps give you better prints. Happy printing!