The article presents the concept of constructing a bicycle frame made of profiles and universal connectors, so that the user can build a frame adapted to his height. The geometry of spatial models was developed and the durability of the proposed solutions was analyzed.

The purpose of thesis was to comprehensively develop the construction project of a long reach compact excavator. Optimal solution was selected and its frames were determined by carrying out classic structural calculations. Then, based on them, a preliminary three-dimensional model was designed in the CAD environment. The prototype was subjected to a series of verification calculations and simulation tests using the finite element method under typical, but also non-standard operating conditions. Then, the structure was optimized and then tested again. Next, technical documentation of the final version was created. In the final part of work, technical and operational parameters of designed compact excavator were summarized and the direction of further actions was determined. The thesis ended with a summary of the observations arose during its implementation.