Holder One is a fully functional, printable “AMS lite Rotary Spool Holder” that can grip not only bigger internal diameter spools (up to 75 mm vs. 58mm) but also smaller internal diameters (as little as 33mm vs. 53mm). It also includes a safety lock that stops the device from detaching and falling from the AMS or A1 mini.

During the printing process, the printer feeder unit pulls filament from the spool. Holder One works in coordination with the printer feeder to enable the spool to rotate continuously, ensuring that the filament is fed with constant adequate tension. This prevents spool erratic rotation, which can result in filament tangling. At the end of a print or when there is a filament color change, and the printer feeds the filament back to the spool, Holder One will rotate back up to 180 degrees, maintaining constant filament tension. This prevents the filament from unwinding outside of the spool, which can cause a jam.

Version 2: I have modified the clutch element to include adjustable tension hooks. This will allow fine-tuning of the winding function to accommodate the differences between print material friction coefficients; see the below picture.

Update 1/22/25

I’ve modified the red lock part to have more friction to stop it from sliding back into the unlock position.

Materials:

For best durability, I recommended printing using PETG, but I've also thoroughly tested it with PLA. I also recommend using the same machine to print all the parts so the tolerances between them are consistent. It has been designed to use a standard #32 rubber band that drives the spool winding mechanism. This rubber band can be purchased at Walmart or Amazon at the links below:

Walmart:

[https://www.walmart.com/ip/Alliance-Size-32-3-x-1-8-Advantage-Rubber-Bands-2632A-2-oz-Bag-of-Approx-88-Bands-Natural/20882070?athbdg=L1102&from=/search&adid=22222222220220085369&wmlspartner=wmtlabs&veh=sem&vtcWeb=UAhkDW-OHOuurrmIM9Z4IA&expiryTime=1707785978935&c=mWebSmartBanner](https://www.walmart.com/ip/Alliance-Size-32-3-x-1-8-Advantage-Rubber-Bands-2632A-2-oz-Bag-of-Approx-88-Bands-Natural/20882070?athbdg=L1102&from=/search&adid=22222222220220085369&wmlspartner=wmtlabs&veh=sem&vtcWeb=UAhkDW-OHOuurrmIM9Z4IA&expiryTime=1707785978935&c=mWebSmartBanner).

Amazon:

[https://www.amazon.com/Universal-Rubber-Bands-Size-432/dp/B000783OSA/ref=sr_1_12?crid=VHUTTQY4QP1F&keywords=32+rubber+bands&qid=1707784264&sprefix=%2332+ruber%2Caps%2C103&sr=8-12](https://www.amazon.com/Universal-Rubber-Bands-Size-432/dp/B000783OSA/ref=sr_1_12?crid=VHUTTQY4QP1F&keywords=32+rubber+bands&qid=1707784264&sprefix=%2332+ruber%2Caps%2C103&sr=8-12)

ASSEMBLY for the Yellow Hexagon Model:

For assembly pictures of the Green model, see the document in the Assembly Guide section.

To install on an A1 mini, please print my Hexagon axis at the link below:

[https://makerworld.com/en/models/188107#profileId-207283](https://makerworld.com/en/models/188107#profileId-207283)

1- Insert the wheel on the Link flange.

2-Insert the Clutch into the link's axis as shown.

3- Insert the Link into the Axis. Make sure the clutch is inside the axis ratchet ring.

4- Insert the Holder into the axis. Make sure that the axis tab goes inside the holder's slot section.

5- Insert the Hook facing downwards into the Holder side slot

6- Insert the two Half Moons on top of the Axis.

7- Press fit the Lock Ring between the two Half Moons, making sure that the chamfered faces to the inside of the Axis.

8- Pre-assemble the locking mechanism by inserting the Clip inside the Clip Lock as shown below, then inserting the assembly into the back of the Axis, making sure the clip lock is pulled back so the Clip tabs can be retracted while being inserted into the axis internal rectangular slot. Once the Clip goes through the Axis rectangular slot, push just the Clip by itself (not the lock) all the way in until it is flushed to the inside of the taper hole.

9- It is very important that you use a standard #32 Rubber band for this next step (another kind of band might be used, but I can not guarantee that it will work properly). Insert the rubber band into the Clutch hook and then attach it to the Holder hook as shown below.

Version 2: I have modified the clutch element to include adjustable tension hooks. This will allow fine-tuning of the winding function to accommodate the differences between print material friction coefficients; see the below picture.

IMPORTANT !! If your clutch is slipping too many teeth at a time while rotating or the spool is not rotating backward enough degrees, please add a second rubberband parallel to the first one to the assembly .

Adding a spool:

1- For a small spool, add a Big Adapter Ring first and then a small ring on top of it, then place the spool on top of both.

2- Add a small Adapter Ring first and then a big one. Gently tighten the Nut Plate enough to stop the spool from spinning against the Holder.

3- Use the ring combinations below to fasten almost any kind of spool size.

Small Spool Mddle - Small Spool Right - Small Spool Left

4- No rings are necessary to hold a Spool ONE, as shown in the middle picture below.

Regular cardboard Spool - Spool ONE Sunlu -Big Diameter Spool

Using Holder ONE and Locking mechanism on the A1 mini and AMS lite.

To use the “Holder ONE” simply insert it into the correct shaft (Green and Yellow for AMS lite and yellow for A1 mini) with the “Clip Lock” pulled out, and once it has been properly inserted, push the “Clip Lock” in and the assembly will be locked in place. To remove it, just pull the “Clip Lock” and remove the Holder.

If you like the design, kindly consider buying me a coffee using the link below

[https://www.buymeacoffee.com/f1dude](https://www.buymeacoffee.com/f1dude)

Thanks!