The work presented here exposes the development and design of a new machine: the recycled plastic filament winder understood as an innovative DIY tool that enables and provides new solutions for the recycling and reuse of plastic, creating customized filaments that can be used in 3D printing, for instance. It is a cost-effective and sustainable solution that helps reduce waste and environmental pollution.The construction of this machine makes possible to create 3D printing filament from discarded plastic. It can be understood as one more option among the existing solutions that, in a profitable and sustainable way, contribute to reduce waste and environmental pollution. Thus, the construction of this winder joins the set of machines that allow to extend the useful life of plastic materials, trying to prevent them from ending up in landfills or seas and oceans; in short, to reduce the amount of plastic waste that every year pollute the ecosystem and the environment.The winder works by taking plastic from disposed containers such as bottles, caps, jerry cans, etc. These containers need to be previously shredded into small plastic shavings or flakes, which are then fed into an extruder machine, where they are melted and, through the winder, this molten mass of plastic is transformed into a thread or filament that can be used in 3D printing. In addition, this winder design also gives users the opportunity to create customized filament since the color, texture and thickness of the filament can be controlled.