I have just started work on a 'Drawer Slide CNC', this is basically a poor mans CNC as rather than using accurate high quality bearings and rails you use a pair of drawer slides.
I have started this project with the expectation that I probably won't finish it and I am perfectly happy with that.
I have started work on loads of projects over the years and in most cases I lost interest along the way meaning things rarely got finished, this used to bother me as I was so close to having these cool things but didn't. For example I have a decent quadcopter sitting at home, this is something I started last year but a software issue meant I didn't finish it. The laser engraver project I started earlier in the year ended without a working system and Kevin has now been left in an incomplete state.
I have recently come to the conclusion that its not the tools, toys or devices I want to play with but rather the build process I am looking forward to.
I really enjoy making these projects, whether thats buying parts and fitting them together, designing and printing or machining them. At some point in the project I have gotten enough enjoyment of of the process and just loose interest and the desire to have the finished item isn't strong enough to get me to continue.
There are exceptions to this rule, for example if I have a specific end goal such as an event or if its a piece of paid or commercial work then that's my motivation and completing things isn't a problem but when I am building something for my pleasure it really is just the build process I am interested in.