AMS Smart Spool Core (Rev. C)

What's new

This is the third revision of the original AMS Smart Spool Core (Rev. A) and its successor AMS Smart Spool Core (Rev. B), bringing some improvements suggested by users:

• the top & bottom side vents are stiffer, thus less prone to letting small beads spill
• container cap now has a marking for identification
• added a notch on the main body to increase the cap grip
• added a small funnel to easily fill the center core (if you opt for steel balls or similar weight)
• added a wrench to ease the container cap opening
• the measuring cup is now shared between standard and XL size, with two separate markers

Revision compatibility

This model is 100% compatible with any part published as Revision B, thus you don't have to reprint any of the accessories. 

On the contrary, Revision A's parts are incompatible and cannot be used.

Plates

All profiles have 6 plates:

1. the container with all the default parts
2. the funnel for the silica gel beads
3. the measuring cup
4. a pair of extra large flanges, for spools with very wide core diameter
5. the cap wrench
6. a container core funnel

Material

They work nicely printed in PLA, but if you plan to leave them inside the spools when in a filament dryer, PETG or ABS is recommended, as PLA will soften at a very low temperature: the print profiles have been set with PETG, but you can confidently print in PLA.

Spool compatibility

When researching for spool compatibility I stumbled onto this website which provides an extensive list of filament spools, something we all want to contribute to. Apparently, the new version is incompatible with only three brands that have centre holes of 50 mm or less: Wanhao, Filament PM, and BQ.
If those are among your favourite brands, I recommend sticking to the previous version.

Spools I've tried myself:

• Bambulab
• eSun (cardboard & plastic)
• Jayo (cardboard)
• Sunlu (plastic)
• Amazon Basic (plastic)
• Overture (cardboard)
• Geeetech (plastic)
• Creality (cardboard & plastic)
• Anycubic (plastic)
• GratKit (cardboard)
• PLA MAX (plastic)

There's only one brand I wasn't able to fit and it's BasicFil, but the spool is so wide it doesn't fit the AMS.

Why another one?

There are many holders for silica gel beads and other desiccants, many others can be used to add weight and avoid the spools jumping around in the AMS. Do we really need another one?

I believe the two concepts can be merged, and the user experience can be improved. This is my attempt.

What's different?

First, this container is not aimed solely at Bambulab spools: it's compatible with any spool having a centre hole of at least 50 mm and a width not greater than 68 mm (73 mm for the XL version), practically any spool that can fit inside the AMS. Some spools cannot accommodate common desiccant containers due to the tabs those containers have on the sides. Those aren't a problem anymore: yeah, I'm talking about those Overture cardboard spools and the infamous Amazon Basic plastic ones….

Second, I'm trading off a little silica gel from a place where they are not contributing much (the very core of the container) to increase the spool weight: I suggest using M6 bolts and nuts, but you can use whatever means you find appropriate. I measured 41 grams with common steel bolts: it might not be a massive weight increase (unless you invest in some tungsten rods), but it's something. The little funnel can ease filling the core with small parts, like steel balls, while the hexagonal core cap can be used to seal whatever you use as a weight, which is especially useful if you go for steel balls or other annoying things. It's meant to be a tight fit and the tabs can help in case you need to remove it. A drop of glue will permanently secure it in place, but be sure to have it completely flat and flush, otherwise, you'll not be able to close the container.

Third, I wanted to reduce print time. There are some beautiful designs out there, but many don't consider that a huge number of tiny walls can render printing these parts a long wait. This container is designed to have great airflow without forcing your printer into a three-hour tedious web construction.

Fourth, and probably the real reason that pushed me into starting this design, prevent the container from sliding off the spool. I keep forgetting I have the desiccant container at the spool core when I go for filament change: when I pull out the spool from the AMS gravity does its job and the containers keep falling off and breaking, especially at the tabs. This design uses two side flanges you can quickly and easily use to lock the container to the spool sides: now the container cannot slide off the side of the spool and it's also a lot more reliable when inside the AMS! When swapping filaments it's up to you to decide if you want to keep the container along with your half-used spool or if you want to remove one flange and move it to the next spool going in.

Fifth, these containers have a slightly greater diameter than many of the most popular ones, partially compensating for the desiccant capacity loss due to the weighted core: more desiccant means more humidity absorption capacity and more weight as well.

The standard version can accommodate 89 cm3 of silica gel (about 62 gr) and the XL version up to 105 cm3 (about 67 gr): with the added weight in the core, you can easily reach and surpass 100 gr of weight well-connected to your filament spool!

Sixth, the apertures on the container sides aim at maximizing the airflow and visibility of the silica beads: you can easily monitor the colour-indicating beads if you use those.

Addons

Funnel

The funnel on the second plate might not be necessary to start with, but if you find these containers useful, it might further improve your experience, making the desiccant load process a lot faster with no silica gel beads jumping around on your floor: it's specifically designed for these containers as it locks in place the very same way the container cap does.

Measuring cup

On the third plate, you can find a measuring cup with two indicating lines, one for the standard and one for the XL version: when your silica gel beads reach the line level you have the right amount going into the container—less fiddling and faster refills, hopefully with no spilling. Obviously, the lower line is for the standard version, while the upper line is for the XL version: one cup fits them both.

XL Flanges

The flanges on the fourth plate are very wide and I've only needed those once when dealing with an unnamed brand spool with a center hole opening so wide the standard flanges barely covered it: you will probably never need them, but in case you will, they are here.

Wrench

The added notch increases the cap grip on the container, but the first few times you try to open the container it can be quite hard and the reduced size of the lips can prove difficult to add the required torque: this wrench will make this task a breeze.

Core Funnel

When filling the center core with things like steel balls, this tiny accessory is practically mandatory: it is designed to stay in place by friction. It should snap in and out easily to be replaced with the center core cap once the filling process is complete.

Sieve

I've also published a sieve to separate silica gel beads that might be too small to get into the container: vents have been designed to accommodate beads of a minimum 1.5mm diameter, and the sieve has 2.5mm holes.

Centering Spring

As per user request, I've designed and published a spring which allows keeping the container completely co-axial with Bambulab Reusable Spools: these are not as convenient as the standard flanges and they are definitely not adaptable to other spools, but if you really want the container centered…

Credits

I wouldn't be fair to other makers without listing all the models I took inspiration from:

• Air Max 1, was my favourite, before this obviously
• High visibility desiccant holder for spools
• Universal spool weight for AMS