First of all we should consider the following points:
- For obvious reasons of easy pricing the plastic of 3D printing filament is sold and managed at source on a weight based. Despite it is distributed in form of filament, useful for the 3D printers. The most common diameters are 1.75 and 3 mm thick.
- 3D printers – especially the slicers algorithms – calculates the printing time based on the – average – Extruder speed integrated with the filament diameter, the nozzle size and the layer thickness. It has sense because as a matter of fact the physics of the slicer is calculating a solid 3D object divided in slices where the speed as well as extrusion temperature impact on the final quality. So while doing the slicing calculations it is easy and useful to collect the number of meters needed to 3D print a certain object.
- Depending on the material we use filament has different performances; I mean same weight corresponds to different metering of the roll (filament diameter makes the difference)
- We know – or it is easy to know the specific weight of the materials, e.g. PLA and ABS have different specific weights: one meter of PLA has different weight than one meter of ABS, same diameter. A good value can be obtained by the filament calculator
- The entire process to measure weight and lenght of the filament (used, remaining etc.) should be cheap and easy and efficient too
- Asking for external – producers/distributors – help making complex changes is senseless. We have a problem and we should solve it. Not change the world to avoid the problem.
Considering the above points the right approach for a dynamic measuring of the 3D printers filament usage is surely weight-based.
About one year ago I have created an original 3D printable filament spool support. The assembly guide is shown in an instructable: 3D Printer Filament Spooler Support Assembly Guide I used for all my 3D printings without problems.
Now the 3D Printer Filament Monitor integrates this support with a weight sensor creating an Arduino based device for real-time filament monitoring. Also in this case the entire structure is fully 3D printed and the images below shows how it is built.