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The study investigates some 3D printing output parameters of a polycaprolactone (PCL) wood-based biopolymer, a category of materials obtained by embedding wood-derived components within polymeric matrices. These wood-based biopolymers have garnered significant focus in recent years due to their environmental friendliness and vast potential across many different fields. A full factorial design with three independent variables (layer height, printing speed, and heat treatment exposure time) at three levels was considered. The research explores printing speeds higher than the speed ranges typically investigated in the existing scientific literature on FDM 3D printing of wood-based polymers. Additionally, in this study, heat treatment is proposed as a post-processing operation to enhance certain crucial proprieties such as surface quality, hardness, mechanical strength, and accuracy. The findings reveal that heat treatment has a positive influence on the investigated output parameters. Notably, 3D printed samples subjected to heat treatment exhibit an average decrease of 112.1% in surface roughness for a 5-min exposure time and 121.73% for a 10-min exposure time. The surface hardness of the samples also improved after applying the heat treatment. The part hardness improved with an average of 0.65%. Furthermore, significant correlations were observed between layer height and surface quality, hardness, printing speed, and tensile strength. Notably, printing speed contributed significantly to the variation in tensile strength, accounting for 52.77% of the parameter’s variation. These insights shed light on the optimization of 3D printing processes for wood-based biopolymers, paving the way for enhanced performance and applicability across diverse fields.

The paper proposes a rapid, straightforward, and inexpensive method for finding the basic parameters of helical gears with an involute profile. The basic parameters envisaged are the normal module, normal profile shift coefficient, and the helix angle. The proposed method uses balls introduced between the teeth and, thus, the contact with the measuring device surfaces is of the point type, and the centres of the balls are positioned symmetrically with respect to the measuring direction. The condition that the centre of the ball occupies an imposed position is mandatory. Additionally, there is the condition of the positions of the contact points between the balls and the flanks of the teeth. Two sets of balls of different sizes are necessary for a measurement. The conditions of the balls’ positioning lead to a system of five unknowns. The methodology of solving the system is detailed and the method is exemplified for an actual helical gear. The new proposed method is based on the distance over pins but, using balls, presents the following advantages: It can be applied equally to all gears, regardless of the odd or even number of teeth. Furthermore, the dimension to be measured is singular compared to the dimension over pins when a maximum value must be found from several measurements.

This paper proposes a new rapid and straightforward method along with a related device for finding the three basic parameters of an actual external involute spur gear. The number of teeth is easily counted, but the other two parameters—the module and the coefficient of profile shift—are difficult to identify. The method is based on the principle of inspection of the precision of gear teeth, using the dimension over pins, when the maximum distance is measured between the lateral surfaces of two cylindrical rollers of well-controlled dimensions, placed into the spaces between teeth. The dimension over pins is applied as a function of the number of teeth (odd or even) and requires experience (and this is the main disadvantage of the method) for finding the correct maximum distance between pins. The new method eliminates this drawback as it proposes a measuring scheme where four identical rollers are used in a designed inspection device. The system is statically determinate and, therefore, the dimension to be measured is unequivocally found. A new relation for the dimension to be measured is deduced and allows for finding the module and the coefficient of profile shift. The inspection device is described and a concrete case is presented for exemplifying the methodology. A further application permits finding the centre distance for an external spur gearing. Unlike the classical technique where the centre distance is obtained based on the centring surfaces of the wheels, the new method implies only dimensions measured through flank measurements, thus eliminating errors introduced by the deviations between the flanks and the centring surfaces of the wheels.

The stabilizer link, also known as the anti-roll bar link or anti-roll bar link, is an important component of a vehicle's suspension. It plays a major role in keeping the vehicle stable during cornering and reducing unwanted vehicle movement. The main function of the anti-roll bar is to reduce body roll during cornering, i.e. when the vehicle turns, the weight is transferred from one wheel to the other on the same axle and this can lead to body roll. The stabiliser linkage provides an inertial link between the two suspension axles and prevents lateral roll. Stopping the roll phenomenon contributes to better vehicle handling and to maintaining optimal contact of the wheels with the road surface. This paper presents studies on a stabilizer bar linkage made of a polymer often used in the automotive industry, namely acrylonitrile butadiene styrene (ABS). This research will show by finite element method the limit values supported in tension for each end with ball joints and identify the areas where concentrated loads are found. The study also uses the application of reverse engineering by scanning a stabilizer bar linkage in the vehicle suspension subassembly. [ABSTRACT FROM AUTHOR]

The creation of the swirl effect is an important process for the operation of ICE (internal combustion engines) with gasoline or diesel, the phenomenon taking place between the intake manifold and the air filter. Precise mixture control is essential for optimizing the combustion process and consequently engine performance and efficiency. This paper presents an experimental study on the possibility of optimizing the air flow through the intake manifold by developing a new air flow turbocharging system by modifying the geometry of the inner surface of the air intake manifold in the engine, which induces a swirling motion in the air flow, creating a homogeneous mixture of the engine fluid. [ABSTRACT FROM AUTHOR]

This article presents investigations on the variation of cutting forces, surface quality and chip shapes obtained in the HPM (Hard Part Machining) process, when turning a case hardened 21NiCrMo2 (AISI 8620/SAE 8620) cementation alloy steel with 3 different hardness values and 3 types of insert materials. This study can be helpful for a better prediction of tool life and surface quality in machining planning. [ABSTRACT FROM AUTHOR]

Considerable scientific work was carried out along the years to understand the physics of the cutting process with the aim of a better control of these processes. This paper investigates the cutting force variation along the cutting edge in orthogonal cutting processes. This study can be helpful for a better prediction of tool wear in machining planning. Two sets of machining tests were carried out considering two different tool geometries. [ABSTRACT FROM AUTHOR]