Fused deposition modelling (FDM) 3D printers have the highest annual growth of 21.15% in the field of 3D printing. FDM desktop 3D printers account for 23.69% of FDM printers. The major drawback of FDM desktop printers is product accuracy, which is particularly pronounced when dimensionally inaccurate and multi-part printed products need to be fit together into a functional assembly. The research presented in this paper aims to determine the accuracy limits of FDM 3D printers when producing elements for assembly using a 3D printer in a tolerance-fit system. A novel method of computer-aided design (CAD) based on ISO 286 and the systematic calibration procedure of 3D printers were presented to achieve the dimensional accuracy of 3D printed parts. For this purpose, a set of nominal dimensions within the clearance fit was selected, and various CAD models were created according to the ISO 286 system of limits and fits. The CAD Slicer software–3D printer interaction was systematically examined for the best hardware and software features. It was found that the Horizontal Expansion parameter should be 0.0 mm and the Hole Horizontal Expansion parameter should be 0.13 mm. The Linear Advance factor was found to be 25. The measurement results showed that the desired tolerance ranges, system, and type of clearance fit could be achieved with a desktop 3D printer. The roundness tolerance for all clearance fits and shaft tolerance ranges in the hole base system was determined to join the parts into a clearance fit.

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

The increasing use of products manufactured by applying additive technologies encourages using materials with better mechanical properties. Depending on the type of material, its initial state, structure and mechanical properties, materials can be categorized differently. Combining polymer materials with different mechanical properties into composite structures makes it possible to obtain materials with better mechanical properties, which are then used on printers based on fused deposition modeling (FDM) 3D printing technology. This paper investigates the mechanical properties of samples made by combining Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) polymer materials. The samples were produced with different proportions of the two materials regarding the number of layers and the infill density. The test was performed according to ISO 527 – 2: 2012 on a Shimadzu AGS-X 10 kN tensile test machine. For comparison, control samples of PLA and ABS materials were printed with 100% infill and showed the highest average force. Samples with a combination of materials did not produce the expected better results than samples made from one material. The reason for this is the occurrence of delamination of individual layers.

The lack of standardization in tissue testing procedures results in a variety of custom-made devices. In the case of the determination of the mechanical properties of tendons, it is sometimes necessary to adapt the existing laboratory equipment for conducting experiments when specific commercial equipment is not applicable to solve issues such as proper gripping to prevent tendon slipping and rupturing, gripping control and manoeuvrability in case of tendon submerging and without contamination of the testing liquid. This paper presents the systematic development, design, and fabrication using 3D printing technology and the application of the double-acting linear pneumatic actuator to overcome such issues. It is designed to do its work submerged in the Ringers’ solution while gripping the tendon along with the clamps. The pneumatic foot valve unit of the Shimadzu AGS-X tensile testing machine controls the actuator thus preventing Ringers’ solution to be contaminated by the machine operator during specimen set-up. The actuator has a length of 60 mm, a bore of 50 mm, and a stroke length of 20 mm. It is designed to operate with an inlet pressure of up to 0.8 MPa. It comprises the cylinder body with the integrated thread, the piston, the piston head, and the gripper jaw. Fused deposition modeling (FDM) has been used as the 3D printing technique, along with polylactic acid (PLA) as the material for 3D printing. The 3D printed double-acting linear pneumatic actuator was developed into an operating prototype. This study could open new frontiers in the field of tissue testing and the development of similar specialized devices for medical purposes.

This paper discusses the possibilities of an automated solution for determining dimensionally accurate and defective products using a computer vision system. In a real industrial environment, research was conducted on a prototype of a quality control...