Comgrow SH02 Filament Dryer Box Review: Does it Improve 3D Prints?

The Comgrow SH02 is designed to accommodate two standard 1kg filament spools simultaneously, addressing a common need for users working with multiple materials or larger prints. The unit incorporates a PTC heater, which owners report heats quickly, reaching optimal drying temperatures in a short timeframe. Sealing is a primary focus of its design, with multiple sealing rings present at various points including the lid, base, and filament outlets. This structure is intended to maintain a low humidity environment. However, some users note the filament outlet holes can be excessively tight, creating resistance during printing and potentially leading to under-extrusion. A notable design aspect mentioned by some users is the lack of included desiccant, which must be purchased separately to enhance its passive storage capabilities.

Setting up the Comgrow SH02 generally appears straightforward, with many owners reporting that it functions as expected upon first use. The device features pre-set temperature and time profiles for nine common filament types, accessible via a single-key interface. This feature simplifies material-specific drying, eliminating the need for manual parameter adjustments. However, some initial programming quirks have been noted where the unit seemed to default to an 'AUTO' mode, making manual override challenging for some users. The touch screen interface is generally considered functional, though one user described it as 'a little touchy.' The control panel is intuitive, making temperature and time adjustments relatively easy once users understand the system's logic.

The primary objective of the Comgrow SH02 is to remove moisture from 3D printing filament, and users consistently report high effectiveness in this regard. Owners frequently highlight significant improvements in print quality, reduced stringing, and enhanced bed adhesion after using dried filament. The unit successfully revives old, moisture-laden spools, making them usable for prototyping or finished prints. While the heating element performs well, a dominant performance characteristic cited by multiple users is fan noise. Several accounts describe the fan as notably loud, producing a 'high pitched migraine maker' or an 'annoying drone,' sometimes louder than the 3D printer itself. This noise level can influence placement decisions, with some users suggesting it is unsuitable for environments where quiet operation is desired. Some users also independently discovered that leaving the lid slightly open or utilizing the moisture release valve at the top enhances drying efficiency, implying the sealed design might sometimes impede moisture expulsion.

The Comgrow SH02 operates with integrated firmware that manages its heating cycles and pre-programmed filament profiles. There are no external software components or a broader ecosystem to consider with this device. Its 'one-key set for 9 types of filaments' simplifies operation, providing default drying temperatures and times. The intelligent safety protection features, including automatic heating cut-off at high temperatures and a fan alarm, contribute to its reliability. The screen displays critical information like drying time remaining and temperature. While functional, there is no disclosed accuracy for the internal humidity sensor, leading some users to compare its readings against external hygrometers. The device's functionality is self-contained.

The Comgrow SH02 is generally regarded as a worthwhile investment for 3D printer owners, particularly given its price point, which typically falls under $100. Many users assert that the improvements in print quality and the ability to salvage old filament justify the cost. The unit's build quality is described as solid, and it performs its core function reliably. Longevity is not extensively commented upon, beyond initial positive experiences of working well. The most significant reliability caveat is the fan's noise level, which some users find intolerable, prompting returns. While the unit provides slots for desiccant, its absence in the package is a minor inconvenience that adds to the overall cost. Despite its limitations, the SH02 offers a compelling value proposition as an effective, dual-spool filament dryer.