3D Printing Group

Created by Abe Gladstone on 15 February, 2018

What causes to fail a big print (More than 15hours) where a small print done successfully( about within 4-5hours) without any issue?

Hello guys...Hope everyone is well during this pandemic.

I have done several small printing in my creality open box printer without any hassle but every time when i tried to print a big one ( which shows about more 15 hours to complete) its not done properly or sometimes partially.
What causes such issue? Looking for expert opinions.
Nozzle= 0.4mm, Print speed 100mm/s, Infill 13%, Filament PLA type,
Printer= Creality open surroundings

Accepted answer

Amongst the most common causes a large print might fail is the quality of the filament. In particular, ruptures because of poor filament storage (too much water has been absorbed or it was placed in direct sunlight) and breaking of the filament because of tangles in the way it was produced are the most recurrent causes and both will be seen as under-extrusion at some point on you print job.

Obstructions inside the filament hose is a common cause for breaking, so make sure your filament can go from one side to the other without resistance.

Also, a good first layer is the basis of a successful printing, so make sure that you height calibration is right.

Finally, move your axes manually to make sure there is close to no resistance in the full stroke of your horizontal movements or that no objects obstruct the movement.

4 Other answers

Because the axis engines got hot and the printers didn't have cooling for it

There could be a lot of things, the nozzle could be hitting parts of the print (if you use prusaslicer, you can tell the printer to lower the bed every time it traverses over part of the print) it could even be something as simple as a bad thermistor or hotend. ($10 dollar replacement on amazon) but it's hard to tell exactly what is going on without any photos though, so post some photos. Best of Luck

One reason your long prints may be failing is that there is heat creep in your hot end where the hot zone inside the nozzle moves past the heat break. This can cause the filament to become molten further up into the hotend reducing the pressure through the nozzle giving under extrusion and also not allowing retraction to occur. In the worst case you will get a nozzle clog and filament jam.
Ensure that your hot end fan is working correctly and at full speed. If this is your issue then replacing the hot end fan and/or the hot end and heat break will resolve.

If you are using the standard Creality hot end with PTFE tubing all the way to the nozzle then an upgrade of the hot end to an All Metal type will dramatically improve your printer and allow you to print a wider range of filament types.

I can say all the recommended stuff here. I also think that the quality of the filament is one of the most typical reasons for a 3d printer like this https://43dprint.org/best-3d-printers-under-200/ to fail a print. The most common causes are ruptures due to poor filament storage (too much water was absorbed or it was placed in direct sunlight) and breaking of the filament due to tangles in the manner it was formed, and both will be observed as under-extrusion at some point on your print job.
Obstructions inside the filament hose are a common cause of breaking, so check sure your filament can move freely from one side to the other.
A good initial layer is also the foundation of a successful print, so make sure your height calibration is correct.
And, physically move your axis to ensure that there is little to no resistance throughout the full stroke of your horizontal motions and that no obstructions are in the way.