# Methodology Proposal, Virtual Simulations and 3D Printed Prototype of a Car Steering Wheel
## 1 Introduction  
Prototype development is a process that primarily takes place in software programs in a 3D virtual space. There is a connection between the design and virtual analyses, the purpose of which is to verify the required mechanical properties of a given prototype. Only after their verification is the actual production and physical testing carried out.  
3D CAD (computer-aided design) software is an integral part of the design. The development of CAD applications is constantly being improved and adapted to the requirements that are subject to designers on the one hand and designers on the other. CAD applications, whether parametric or explicit, are still incorporating a variety of functionality requirements based on the requirements of their clients to satisfy old clients and attract the widest possible number of new users. They even develop common platforms for the use of parametric functionalities with explicit ones, and thus, 3D modelling takes on a new dimension [1, 2, 3, 4].  
The virtual world of 3D construction is currently increasingly realized through 3D printing [5, 6, 7, 8, 9, 10]. Frequently used materials are plastics (ABS--Acrylonitrile Butadiene Styrene and PLA--Polylactic acid), gypsum composite, photopolymer, polyamide, resin, wax, ceramics, paper, metal (steel, brass, silver, bronze, gold or titanium), but also proteins, carbohydrates, and sugars used in 3D printing of food or even cells in 3D printing of biological tissue [11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21].  
The main goal of companies that develop 3D printing and printers is to print the most accurate virtual model possible into a real form. Many 3D printers are able to print virtualmodel files modified and simplified into mostly STL (stereolithography) format, where, of course, there are inaccuracies. 3D printer software programmers also work with companies that program 3D CAD applications. Many 3D CAD applications are already able to send their virtual model directly to print without further modification of shapes and file formats. 3D printing is very efficient because the process is automated, and one printer can print a number of products in different shapes. Production efficiency is increasing, and final production costs are decreasing.  
The number and different material compositions of usable materials in 3D printing are very extensive and are constantly growing. Products that are manufactured in this way are used in the commercial sphere. It is necessary to undergo appropriate tests of mechanical properties in order to verify their strength, durability, resistance to the required environmental influences, etc.  
Many industries use 3D printing for the production of components that are considered small-series or customized. For example, many car companies offer consumers the opportunity to customize their vehicles with customized components [22; 23; 24; 25; 26; 27; 28]. Their production through 3D printing is relatively fast and allows car manufacturers to reduce delivery times and production costs for small-volume parts and custom production. This is partly because the technology eliminates the need to create individual tooling for each customized element, which would be financially impractical.  
The aim of the work is to propose a methodology for creating a prototype of a virtual model of a passenger car steering wheel and then to test its mechanical properties. The main points are theoretical knowledge of the issue, defining material characteristics, and performing stress-strain simulations that will confirm the desired properties of the prototype. The following is a selection of suitable 3D printers according to the required materials, the dimensions of the printer's working areas, and last but not least, the color options of the printing materials. The testing part is also important, where standardized samples will be subjected to compression and hardness tests in order to verify the required mechanical properties with deformation tests.