Running Out Of Filament

This issue is one of the easiest to diagnose but also among the most frustrating when it occurs. It is possible to assume there is enough filament for a 400-gram print, only to run out of material 20 hours in, with just a few layers remaining.

To prevent this problem, consider the following precautions:

Weigh the Empty Spool Record the weight in grams of an empty spool from the filament manufacturer in use. While there may be some variation, this provides a reliable starting point. Weigh the spool intended for the next print, subtract the weight of the empty spool, and estimate the remaining filament. Allow for a buffer of at least 20 grams to account for spool tolerances.

Pause at Layer Height When starting a print with a spool that does not have enough filament to complete the job, add a "Pause at Layer Height" command in the slicing software. In Cura, navigate to "Extensions" > "Post-Processing" > "Modify G-Code," then add the "Pause at Height" script. Select the desired layer or height for the printer to pause, enabling a spool change. This feature is especially useful for large prints or when a full spool is not available. It can also be used to switch filament colors partway through a print.

Understand Material Density Slicing programs often estimate material usage in grams, but this may be inaccurate if the material differs from the default machine settings. For example, estimates are often based on the density of PLA. If the estimate is given in meters, a simple calculation can convert this to grams for the specific material.

PLA is 1.25 grams per cubic cm. If you were using 1.75mm diameter filament, one meter of filament would be 2.41 cubic cm in volume.

1 meter of PLA 1.75mm filament would then be equal to 2.41 x 1.25, or 3.0125 grams. A 1,000 gram spool of PLA should be roughly 331 meters.

Using that 2.41 cubic cm in volume for 1.75 filament, you can use the data below to figure out how many grams of material your print expects to use.

These numbers are generic and will vary depending on the manufacturer:

• PLA: 1.25 g/ccm – 3.01 grams per meter (1.75mm filament)

• ABS: 1.04 g/ccm – 2.51 grams per meter (1.75mm filament)

• PET: 1.38 g/ccm – 3.33 grams per meter (1.75mm filament)

• Most Nylons: 1.13 g/ccm – 2.72 grams per meter (1.75mm filament)

For 2.85mm filament, use 6.38 cubic centimeters as the volume per meter.

To Summarize:

1.75 mm filament = 2.41 cubic CM in volume for 1 meter of filament. 2.41 x density = grams of filament in 1 meter of filament. Spool weight/grams of filament in 1 meter of filament = length of filament in meters

NOTE: All manufacturers have different specific densities for their materials. For instance - our Polymaker ABS has a density of 1.12 g/ccm. This means if you use the above 1.04 g/ccm to calculate how much material you will use, you will underestimate the actual value. This means you should always use the manufacturers density in your slicer to get a proper estimation.

Use a Filament Runout Sensor Many 3D printers now include a filament runout sensor, or one can be added with some firmware adjustments. These sensors are inexpensive and will pause the print when filament is no longer detected. This allows for a spool change and resumption of the print, reducing the risk of failed prints due to filament depletion.

Summary of Fixes and Precautions

• Weigh the spool before starting a print.

• Add a pause at a specific layer height to allow for filament changes if the spool is low.

• Calculate estimated filament requirements based on the density of the material in use.

• Utilize a filament runout sensor to automatically pause prints when filament runs out.