![](https://www.fabbaloo.com/wp-content/uploads/2024/08/spool-scale-cover.jpg)
I’ve been reading about “digital spools” that automatically weigh 3D printer filament spools.
The problem being solved here is the dilemma encountered by 3D printer operators when getting to the end of a spool: exactly how much material is left on the spool, and will it be sufficient for the next job?
Many FFF 3D printers now include a “filament out” sensor to alert the operator that it’s time to swap in a new spool. However, that implies the job is paused, and that might result in wasted overnight hours when the print could have been completed.
In some cases you really do want to know if the spool will be sufficient. Many times I’ve loaded up a fresh spool for this reason, but over time you end up with a lot of partially used spools.
The digital spool might be a way to answer this question. It’s basically a scale that’s built into a spool mount. The scale weighs the spool and the remaining filament and provides a very close report on the remaining material. If it’s more than the job requires, you’re good to go.
Creality actually sells one of these as an accessory, the “Digital Spool Rack-S”, which fits on several of their systems. At top you can see how this system is designed to mount at the top of some Creality FFF devices. As of this writing, it seems to be sold out.
Last year Chuck Hellebuyck did a short review of this product.
![](https://www.fabbaloo.com/wp-content/uploads/2024/08/spool-scale-interlink.jpg)
I searched extensively to see what other options might exist, and for some reason few other options came up. One was a DIY project from InterlinkKnight, which can be viewed on Instructables.
![](https://www.fabbaloo.com/wp-content/uploads/2024/08/spool-scale-polaroid.jpg)
It also seems that some years ago Polaroid’s consumer 3D printing arm offered a tabletop spool holder that included a digital scale for their “Polaroid Precise” spools. However, this is no longer offered.
![](https://www.fabbaloo.com/wp-content/uploads/2024/08/spool-scale-andrews.jpg)
Another DIY project of this type was published on “Nuts & Volts” several years ago, which seems quite similar to the Creality version. This article is quite detailed and provides complete instructions for building this device, including the necessary software. It also seems to include a database for spool types.
Finally, on Printables there is another project of this type, the “Spool Holder Weight Measure“, which is a tabletop affair similar to the Polaroid approach. However, the instructions are nowhere near as detailed as the others.
I’m wondering why this relatively inexpensive function hasn’t been integrated into desktop FFF 3D printers. Operators would surely find it quite useful. The concept has been around for years, yet it hasn’t made its way into product feature lists, whereas multiple other features have done so.
Could it be that operators simply use a standard inexpensive digital scale to weigh spools before mounting them? Maybe it isn’t worth the effort and cost to integrated spool weight? Maybe everyone just uses fresh spools for questionable jobs?
I believe this function could provide value if properly integrated into desktop FFF 3D printers. Imagine, when starting a job, the printer asks: “there appears to be insufficient material mounted to complete this job. Do you want to proceed?”
I would absolutely appreciate that warning. Wouldn’t you?