Weak Infill

All troubleshooting pages are a work in progress.

Identifying Weak Infill

Infill tracks should look the same as those that make up the shells of your print. If they’re coming out wispy and thin, or not connecting properly, they’re too weak and won’t do their job of keeping your print strong.


This is a type of under-extrusion. Frequently it can be caused by trying to print too quickly and putting too much pressure in the nozzle of your HotEnd. Alternatively, there might just not be enough filament flowing through your HotEnd, in which case you should increase the flow rate.



Lower printing speed

Extrusion Rate

Increase extrusion rate


Infill is usually the part of your prints that is printed the fastest. Because of that, filament flows out of your HotEnd fastest while printing infill. Since HotEnds have a maximum volume of filament they can extrude at a time, you might be hitting that limit while printing infill. Lower your printing speed to reduce the pressure in your HotEnd and give it more time to melt your filament.

Some might suggest to raise your printing temperatures to melt filament faster, but typically you want your printing temperature to be determined by either the quality of your prints (reducing stringing and sagging) or their strength (improving inter-layer adhesion).

Extrusion Rate

If you’re seeing other symptoms of under-extrusion in your prints, you should increase your extrusion multiplier to push more filament while printing. This will help infill lines print stronger and more consistently.