MarsWork S1 Reusable Spool First Look: Refill Swaps Without the Twist Lock

As a short disclaimer, MarsWork sent me an S1 reusable spool and a roll of their PLA Basic free of charge, and this is not a paid feature. I am currently away and have not printed with either of them yet, so this article covers how the system works based on MarsWork’s published information and the unit as it arrived, while printing performance has not been tested.

What I want to do here is explain how MarsWork’s refill system works, what makes the S1 spool different from the twist-lock reusable spool most refill users already know, and what I still need to check once I have used it.

MarsWork’s refill system is aimed at Bambu Lab AMS users

MarsWork sells PLA in Basic, Matte and Silk finishes, both as refills and pre-loaded on a spool, alongside two reusable spools (the plastic S1 and the aluminium MS2) and a filament management kit. The PLA Basic is listed as optimised for the Bambu PLA Basic preset, and the S1 is described as compatible with the AMS, so the brand appears strongly targeted at Bambu Lab users and AMS workflows.

How the S1 differs from a twist-lock spool

Refill filament comes wound on a cardboard core without a plastic spool, and you mount it on a reusable spool that you keep. Bambu Lab’s reusable spool uses two halves that lock by rotating the narrow half clockwise into the wide half until it clicks. Some users on Bambu Lab’s forum have reported refill cores that are very tight on the spool and filament coming loose while fitting them, while other users say they have had no problems.

The S1 has no twist step. You press two latch buttons on the hub and lift the narrow half off, place the refill into the wide half, then press both sides down at the same time until both latches lock. The instructions printed on the box warn that pressing only one side can leave the spool incompletely locked, and in that state the filament can unroll, so both latches need to be checked before the spool goes into the AMS.

Features built around partly used refills

Most of what sets the S1 apart is aimed at taking a roll off before it is finished. It comes with a hook-and-loop strap to secure a partly used refill before unlocking the spool, so the coils do not spring loose when the roll comes off, and a built-in clip to hold the filament end. The hub has a slot for a printable colour card module, according to the insert on the spool, and MarsWork publishes free colour card models on its MakerWorld page. The side of the spool has an oval groove for the included filament label, so the material and colour can be identified without unwinding anything.

MarsWork gives two temperature limits for the S1. With filament loaded, the maximum is 70 °C. When the spool is empty, the maximum is 90 °C, although MarsWork recommends staying at 70 °C for daily use to extend the spool’s lifespan. MarsWork’s drying recommendation for PLA Basic is 50 °C for 8 hours, which is below the 70 °C loaded limit.

PLA Basic pricing and published specifications

The roll I received arrived pre-loaded on an S1 spool inside a plastic bag, with a cardboard insert on the hub reminding you to check both latches and to strap the filament before unlocking the spool. MarsWork lists the PLA Basic in 29 colours with a nozzle temperature range of 190 to 230 °C, and says each roll is triple-dried and sealed with desiccant, arriving below 0.3% moisture. MarsWork’s product pages do not mention an RFID tag, so Bambu AMS users should expect to set the filament type and colour manually.

According to MarsWork, the S1 fits refills with a cardboard core inner diameter of approximately 82 mm. In a Bambu Lab forum thread asking which refill brands fit Bambu spools, one user linked MarsWork refills and said they had printed around five rolls without issues. That is a single user’s experience rather than confirmed compatibility, but it suggests existing Bambu spool owners may be able to try the filament without buying the S1.

What I still need to test

None of the following can be judged from the box, so I will check them once I have used the spool and filament. The first is how the latches hold up after repeated swaps, and whether a one-sided lock is easy to miss in practice. The second is how the S1 feeds in the AMS, including near the end of a roll. The third is print quality of the PLA Basic on the Bambu PLA Basic preset, along with whether the moisture claim holds on a roll that has been opened. I also want to confirm how well MarsWork refills fit a Bambu reusable spool and how Bambu refills fit the S1.

I will either update this article with those results or publish them as a separate spool and PLA test.

Sources

• Plastic Reusable Spool S1, MarsWork
• PLA Basic, MarsWork
• MarsWork Official, MakerWorld
• Bambu Reusable Spool, Bambu Lab US Store
• Which brands of refill filaments fit Bambu spools?, Bambu Lab Forum
• Sick & Tired of Bambu Filament Refills, Bambu Lab Forum