Many 3D printing enthusiasts, in pursuit of optimizing their machines, often turn to aftermarket hotend components. Recently, I’ve been experimenting with the “V2” Aliexpress hotends, integrating a modified V6 Diamond Back nozzle for enhanced performance. While the initial results seemed promising, persistent issues with temperature regulation have surfaced, particularly when pushing the printer to higher speeds.
Initially, I encountered problems with the thermistors and ceramic heating elements included in these Aliexpress kits. When operating the printer at what I would consider moderately increased speeds—around 16-20mm/s^3 flow rate with PLA—temperature malfunctions became frequent. Specifically, when printing at speeds exceeding 16mm/s^3, I observed a gradual decrease in the hotend temperature displayed on my X1. During infill and bottom floor layers, with a target temperature of 220°C, the temperature would slowly decline to 219°C, 218°C, and so on. This descent would continue until it reached a point, around 214°C, where the printer’s safety mechanism triggered a malfunction message, pausing the print. Although resuming the print was possible, the issue would typically recur within minutes, leading to further interruptions.
Interestingly, the solution to this temperature instability was surprisingly straightforward. By replacing the aftermarket thermistor and ceramic heater with the original components from the stock hotend within the “V2” hotend assembly, the temperature drop issue largely disappeared. This pointed towards a potential deficiency in the quality or specifications of the Aliexpress components.
Further compounding the issue, some of the Aliexpress ceramic heaters exhibited a concerning tendency to fail catastrophically. On multiple occasions—three times consecutively—these heaters “detonated” internally immediately upon being instructed to heat up. It appeared the rapid heating process induced stress fractures within the ceramic element, leading to immediate failure.
While acknowledging the inherent variability in quality associated with Aliexpress components, the consistent low-temperature runoff at relatively normal flow rates remained perplexing. One potential explanation is that the Pulse Width Modulation (PWM) tuning, responsible for maintaining consistent heat output, might not be properly calibrated for these aftermarket heaters. Alternatively, the thermistors themselves could be providing inaccurate temperature readings, contributing to the control issues. It’s noteworthy that these issues arose consistently across approximately six sets of these Aliexpress units, with the problem only being resolved by reverting to the stock Bambu components. This suggests a systemic issue rather than isolated incidents.
My attempts to utilize these aftermarket thermistors and ceramic heaters with a CHT (Core Heating Technology) hotend setup on another machine yielded similar results. When targeting higher flow rates, aiming for 25mm/s^3—a speed theoretically achievable with CHT nozzles—the heating element struggled to maintain temperature. Even when paired with high-performance Slice Engineering Boron Nitride thermal paste, the aftermarket heating elements proved inadequate in demanding high-flow scenarios.
In conclusion, while aftermarket hotend components from platforms like Aliexpress can offer an accessible entry point for printer modification, experiences with temperature instability and component failures suggest potential compromises in quality and reliability. For users prioritizing consistent performance and pushing the boundaries of printing speed, investing in higher-quality, well-calibrated components or sticking with stock parts might be a more dependable approach to avoid frustrating temperature-related print failures.
