Cash flow positive often shows up at year 3 or 4 on most hockey stick graphs, although the vast majority of startups don't have the hard data from the market to back up this projection, so any 5-year projections as well as the cash-positive date should be taken with a large grain of salt.
As a general rule of thumb, hardware and physical infrastructure startups with significant capital expenses (such as non recurring engineering expenses and tooling and equipment costs, and in some cases, siting / building costs) tend to take longer to get to cash flow positive than certain types of consumer oriented software businesses with a capital efficient cost structure. That said, an enterprise software company selling large deals to large corporations will have a much longer time to cash positive due to the long sales cycle (and the long lead time for new field sales personnel to become productive in the event field sales is required - which remains the mainstream go-to-market method for selling large scale deals, including SaaS deals.
Hardware is tough, and Ben Einstein, GP at BoltVC (a hardware oriented seed stage VC and accelerator) has a very good piece on the financial picture behind a consumer electronics startup. When you are talking about industrial level hardware you are in a whole new realm. Product delays can be costly because you can easily run out of runway before your product ships, so in order to succeed you will need to raise more than you think you need. For instance, the Tesla X is late by two years - they can survive this as they are very well funded, but a delay for a less well funded industrial hardware startup might not.