LENGTH vs. MASS of filament on a spool
FFF 3D prints are made by extruding volumes of material through a nozzle. For a given diameter (e.g. 1.75mm), the volume of the filament is directly correlated with its length. It makes more sense to measure the material by length (so implicitly by volume) as that will give you a better idea of how many (and how big) objects you can print from one spool.
For example, with 600m of filament, you can print the same volume of objects regardless of material, while that volume will weigh 1.8kg for PLA, 1.5kg for ABS or 1.6kg for TPU.
Also, it makes economic sense to standardize the spool dimensions and the packing material regardless of the material. For the manufacturers who sell their filament by mass, that might be a problem, as packing 1kg of PLA on their standard spool is ok, while packing 1kg of ABS on the same spool results in an over-filled spool that might create problems for the end-user.
Of course, even as we pack the spools by the length, we always note the weight of material included, as this is helpful information.
GET MORE OUT OF YOUR SPOOL
We all know that when the spool is close to its end, we’re reluctant to use that last bit for a sizeable new print to avoid the hassle (and the failure risk) involved with changing filament mid-print. The result is often a bunch of almost-empty spools that we don’t want to throw away but that we don’t use either. Replitech spools are almost double in size, and although that does not eliminate almost-empty spool syndrome, it will reduce it.
The spool also has a visual remaining quantity indicator (in meters of left filament). Most of the slicers estimate the length of filament needed for a specific print, which will help the user estimate if the filament remaining on a spool is enough for a new print.
Having just one spool hold almost double the filament decreases the amount of spool waste generated by 3D printing. Although nearly double, we designed our spool to use less plastic than the smaller 1kg spools from other manufacturers, so the waste reduction is significant.
Further, if feasible (like for all the local customers who buy directly from our shop), we will take an empty spool back and reuse it, giving the customer a rebate on the next purchase equivalent to our cost of the spool (currently CAD $2).
PRACTICAL SIZE and configuration
Our spool holds almost double the standard 1kg spools filament, but that doesn’t mean it’s not printer-friendly! It is Ø210mm outside diameter and 84.2mm wide with an inside hole diameter of Ø52mm. It can be used on most 3D printers without modifications or new holders.
It also fits many standard dryers (like the PrintDry Filament Dryer PRO), and the many hex holes in the side of the spool allow for good warm air circulation, which improves the drying conditions.
Also, the many holes on the sides allow you to quickly find a place to weave the end of the filament to prevent tangling. Remember, a spool never comes tangled from the manufacturer (us or any other). To understand how filament tangling works, please read this excellent article posted by Alec from MatterHackers.
The larger volume of the filament we pack into our spools means we can ship more filament to you without significantly increasing shipping and packaging costs. We are happy to pass on these savings to you.
By using these spools, we can offer premium, high-quality filament made from the best existing raw materials for 3D printing at a better price. Our cost per unit of volume is equivalent to or lower than other manufacturer filaments made from mediocre raw materials or materials not suited for 3D printing.