There was an Elon tidbit last year where he disclosed that every Model 3 is precision measured via laser instruments to within 0.01 mm, hundreds of times along the assembly lines, which would be excellent instrumentation to drive the QA process.
I lead UI and UX design for the measurement software that controls these measurement instruments and does the geometric analysis. We are owned by a major manufacturer of measurement hardware including hardware in use by Tesla and other auto manufacturers. We also design integrated automated robot/scanner systems that recalibrate robot positional accuracy based off precision measurement data. One of our systems is a robot with a laser line scanner that performs automated gap and flush measurement and analysis on an assembly line.
Few points:
1. The crash test lab video Tesla released yesterday had a short ~2 second shot of a laser line scanner (handheld) measuring the airbag area of the steering wheel.
2. I won’t contradict the number you gave because I didn’t hear Elon’s original quote, but: the laser scanners of that type cannot get accuracies to 0.01mm. Real accuracy, when considering uncertainty in locating the instrument to the coordinate reference frame, is closer to 0.002” (0.05mm) for that type of instrument on a good day.
However, portable CMM arms which can physically probe the part (instead of a non-contact system like a laser scanner) can get advertised repeatability to around 0.01mm (~0.0004”), but real-world accuracy is going to be closer to twice that value on a good day. (This is for portable systems that are in-use by Tesla).
3. Errors such as those in panel gap and flush come from two sources: tolerance errors from the individual parts (panels, frame, hinges, etc), and errors resulting from the assembly and mating of those parts. Usually most errors are a result of the assembly of those parts (as Kruggerand mentioned) and not errors in the individual part tolerances...although this can vary from one situation to the next. Assembly is often tweaked to compensate for individual part errors to minimize total assembly errors.
4. It is possible to get higher accuracy with fixed CMM systems, but they are tabletop devices that are not feasible to use for an assembled vehicle.
Looking at random comments on social media about Tesla today, the most common non-TSLAQ criticism of Tesla and the one probably limiting orders the most (whether driven by FUD or due to true precision issues from the past) seems to be quality: panel gaps and interior quality.
Evidenced by Bob Lutz’s praise of the gaps on a more recent Model 3, Tesla has advanced by leaps and bounds in this area. Indeed, recent 3s I’ve sat in appear to be of equivalent quality/precision of other premium and luxury automakers.
Unfortunately, because of the acquired perception of quality issues, Tesla will probably have to work extra-hard compared to other manufacturers to correct this perception and eliminate this stain on Tesla’s brand image by the pessimistic public. It’s not fair, but reality at this point.
Fortunately they are the manufacturer I’d trust most to innovate in this area.