An advantage of using additive manufacturing (AM) processes as opposed to conventional fabrication methods is that the additional degrees of freedom in design allow compact and at the same time lightweight components to be manufactured. In addition, AM reduces the material consumption, resulting in a more cost efficient production. Among others, the field of laser development benefits from the progressive implementation of AM-related opportunities. However, this integration is mostly limited to single components. In contrast, we present a compact, lightweight solid-state laser oscillator system for low-power applications based on additively manufactured optomechanical components via Fused Filament Fabrication (FFF). The laser system is based on a Nd:YVO4-crystal pumped externally with a fiber-coupled laser diode at a wavelength of 808nm and a maximum output power of 3 W. The commercial optical components, such as lenses and the crystal, are firmly embedded via FFF in quasi-monolithic optomechanics. Thereby, they are fixed at their position and thus secured against misalignment. Furthermore, sensor technology for temperature monitoring is implemented into the structure. The possibility of the FFF process to work with different materials in parallel is used here. This multi-material printing approach enables the use of the appropriate polymer for the individual mechanical and thermal requirements for any structural part. The thermal stability of the printed structures is evaluated to ensure damage-free operation of the 3D-printed polymer optomechanics. Furthermore, output power, optical-tooptical efficiency, beam pointing, and spatial beam profile of the laser system are measured for several on- and off-switching cycles as well as for long-term operation.