Filament spool
!!Filament supply Fused filament material is generally supplied in spools.
There was distribution in open loops but this tend to disappear except for samples or costly specific filaments.
Some printer manufacturers supplied filament in proprietary cartridges, some of them having electronic chip to store data and usage. In consumer printer market, this faced some opposition.
The problem of spool is there is no dimension standard nor labelling.
Also, generally the usage indication on labels are vague, only indicating a range of temperature and speed, but no extrusion coefficient and no physical properties. Reference to applicable health and safety regulation is also quite rare.
!!Attempt of spool standardisation In march 2014, RichRap made a web page to list all existing spools and make a detailed standard, also defining spool material. He updated this standard in november 2014. It was endorsed by the 3D printing association. This standard was discussed in forums but without contact or approval from filament manufacturer, was never adopted.
!!Trends for dimensions Since the paper of Richrap, the range of spool size have decreased and there is a trend toward spools of 200mm diameter with a hole of 51-53mm, with hub diameter significantly larger than the spool hole diameter, from 85mm to 100mm. A large hub is required for some filament material like PLA which have problem to unwind from too small diameters and may break.
The spool width depends from the material quantity, typically 40mm for 500g of material, 54mm for 700g and 68mm for 1kg.
It shall be noted that as the density of material are different, the same weight correspond to different volume and filament length.
However, some manufacturers, as Taulman, still supply small spools with small holes, making them difficult to install on most standard supports. They mostly supply flexible filament, which allow small hubs.
RepRapper A chinese manufacturer, is still using 155mm diameter spool, width 90mm with a hole 54mm , and a too small hub diameter of 58mm.
!!Labelling An attempt to [create a standard] QR-code for labels is in progress, but somewhat idling. QR code need a camera for recognition, but there are smartphone applications to read them, and it is feasable to transmit data from smartphone to printer via Wifi, but this need another standard.
