Nowadays with all the progress about 3D printing and sustainable energy and the need of automation it is our everyday life to save time. Therefore, our mission is to build an autonomous lawn mower connected to a static windmill both with mostly 3D printed parts. Our vision of the project is a lawn mower which can cut grass autonomously inside a restricted area, powered by a static windmill with a docking station and each mostly with 3D printed parts.
The lawnmower build for this project is based on the RepRap Lawnmower plans sold by Digital River GmbH. The first iteration was designed in 2009 by Andreas Haeuser to be built from aluminium, steel and other materials requiring a large well-equipped workshop to recreate as a hobbyist. With the rise of 3D printers Andreas changed the design to be printed on simple do-it-yourself 3D printers. With this design change the electronics where also simplified to work with the Arduino board. This makes the system nice to print, easy to use and simple to operate. This model is designed to cut a lawn up to 500 m², in Central European Climate, on wavy uneven ground and fertile soil that is not being fertilized by the owner. The machine is not used to cut long grass however the main usage of the machine is to trim the overnight growth of the grass the following day thus maintaining a constant grass length over time.
At the beginning an inventory was created to visualize what was needed to order and what to print. In this project, the printing time takes at least 340 hrs if everything works well and it is often not the case. Therefore, the milestones involving printing are spread out in the timeline. The lawn mower and the wind turbine can be made independently so milestones are close to each other. After completing those, the team is going to focus resources on the docking station, first the design and manufacturing and then testing with the lawn mower and the wind turbine. An optional milestone has been added, if the group find the time to implement it there will be solar panels on the lawn mower.
The risk areas of the project are divided in 5 phases divided in different sub phases. This is made from the opinions of the team members. The numbers represent the impact of each phase/sub phase and the red cones represents the probability. This way the team can truly understand the impact of each risk and its probability to complete the project in good conditions. The phase with the highest chance to happened is the weather conditions because the team is working on a lawn mower in Finland during fall/winter season, the snow or the ice can disturb some testing in the grass. However, this has a low impact on the project, where all the project management, team members and the printing process have a high impact on this project but a low probability of happening.