## 1 Introduction  
Additive manufacturing (AM) has emerged as a manufacturing process that offers greater design freedom, material efficiency, and the ability to produce complex geometries in advance of traditional manufacturing processes [1]. Although the initial application of AM was focused on its use for rapid prototyping, with continued advances in materials, hardware, and process control, AM has evolved into a robust manufacturing method capable of producing functional end-use components with mechanical properties and precision suitable for industrial applications [2,3]. Among the various additive manufacturing technologies, Fused Filament Fabrication (FFF) is widely used due to its accessibility, versatility, and cost effectiveness. FFF allows using a wide range of materials, which makes it possible to adapt to varying functional and structural requirements [4]. This flexibility makes it suitable for applications ranging from model making to high-performance parts used in demanding environments. With the capabilities of FFF manufacturing technology continuously advancing, there has been a growing focus on developing and utilizing reinforced materials to overcome some of the inherent limitations of standard filaments [5]. The incorporation of reinforcing, such as fibers, particles, or blends, has been shown to be an effective strategy for enhancing the mechanical, thermal, and dimensional stability of printed components [6,7], thereby expanding the range of functional applications for FFF-manufactured parts. Among the different reinforced materials, polylactic acid (PLA) reinforced with short carbon fibers has emerged as a material of choice [8]. This material combines the ease of processing and printability of PLA with the enhanced mechanical properties provided by carbon fiber reinforcement [9,10]. Furthermore, PLA is a biodegradable material under controlled conditions, making it one of the most environmentally sustainable materials used in additive manufacturing. Incorporating carbon fibers into the PLA matrix can be achieved without significantly compromising this sustainability profile, providing a balanced solution that supports both technical performance and environmental responsibility [11,12]. Recent studies on the processing of carbon fiber-reinforced composites (CFRCs) have demonstrated significant improvements in both mechanical and thermal performance, expanding their applicability in structural applications [13,14]. In the context of additive manufacturing, the incorporation of short or continuous carbon fibers (CF) into thermoplastic matrices has been widely investigated to enhance strength, stiffness, and thermal stability. The content, orientation, and interfacial bonding of the fibers have been identified as critical processing parameters that influence the final properties of CFRCs. In addition, post-processing techniques such as thermal treatments and subtractive machining have been applied to improve surface finish and dimensional accuracy in printed CFRC components [15,16]. Surface finish is a critical aspect of any manufactured part as it directly influences its aesthetic appearance, functional performance, and dimensional accuracy. In addition, the surface topography can affect properties such as friction, wear resistance, sealing ability, and even mechanical strength [17, 18, 19]. Achieving an appropriate surface finish is often essential for the part to meet industrial requirements or to be integrated into larger assemblies without further modification. Consequently, improving the surface finish is often necessary to ensure functionality, reliability, and performance. This has led to increased interest in post-processing techniques such as mechanical finishing, chemical smoothing, or hybrid manufacturing strategies [20,21].