anticitizen13.7
Not posting at TMC after 9/17/2018
Call me ignorant but I don't see how time between RC and start of production correlate to speed of ramp. If they started production in mid 2018 then we would be even more behind and financially risky.
The only thing which this time can affect is quality of build which is fine from what we've seen.
It takes time to validate components, iterate on them, and re-validate. Tesla had discussed ways to shorten the cycle by working closely with suppliers (covered in previous conference calls back in 2016 from what I remember), but it still takes time. It takes time to set up and validate the manufacturing line itself. Changes in components might require changes in the line.
Note that I am not saying that mid-2018 is when they should start production. What I am saying is that mid-2018 was always realistically the earliest they could have started churning out Model 3's in the thousands/week volume.
Edit: I believe that early Model 3's were built on a production process that wasn't the final production line. Tesla has, as far as I know, been setting up and slowly running the finalized line over the past few months, or building "the machine that builds the machines".