Inside a Z-Nikkor - Teardown 24-70 f2.8S

[chambeshi]

This detailed article speaks for itself. It also is an apt example of true quality in a detailed report, which is comparatively rare in what's passed off on the www for reviews of photographic gear.

https://www.lensrentals.com/blog/2020/01/finally-the-nikon-z-24-70mm-f2-8-s-lens-teardown/

"....Forever, during Nikon tear-downs, I’ve made snarky comments about the old-fashioned look they have inside; soldered wires here and there, flexes wandering aimlessly, random secondary circuit boards, etc. Well, no more. Look at this engineering right here: neat flexes running directly where they’re heading placed in recessed channels in the barrel and thoroughly taped in place. Superb!"

".....All the screws have Loctite to hold them in place, but extra dried Loctite can break off and become that ‘huge’ chunk of dust in the lens. (Huge usually equals about 0.1mm to 0.2mm; but lenses, as we learned in grade school, make things look bigger.) That yellow tape everywhere prevents any Loctite around the screws from getting down into the optical parts of the lens. Nicely done, Nikon. Very nicely done...."

"...Conclusions
As you can probably tell from our struggles doing this disassembly, the Nikon Z lenses are very different than their legacy lenses. They’re also different than what we’ve seen from other manufacturers. That suggests Nikon Z lenses, like Canon R lenses, are a completely new optomechanical design, probably done entirely in-house.

The engineering itself is incredible in most ways. The neatly laid out and solidly adhered flexes reflect the careful design. The taping of every possible point that Loctite or anything else could get in the lens does, too. The design is logical and clean; the difficulties in the tear-down were ours. Now that we know our way around, disassembly won’t be bad at all.

I will complain about the fact that filter-ring or hood-slot damage means an expensive repair. That was not well thought out; those are common repairs, and they’re going to be pricey on this lens. But the lens is well-engineered, and I see no other weak points to make me think it will be anything less than reliable.

I’m sure various internet experts have strong opinions about stepper motors versus electromagnetic motors versus piezo motors for linear focusing. I don’t have enough knowledge to comment other than the vague general understanding that EM is probably the fastest and stepper perhaps more accurate. I would simply caution people that taking engineering reports of how well a given motor does this or that may not be very well reflected in how a lens performs autofocus. Autofocus, like lens disassembly, is a complicated profession."

[Netr]

I found this to be a fascinating read. He doesn't just tell you what he did, but why he did it and how he felt while he was doing it.

[Erik Lund]

Looks like a very well thought out, designed and matured for production - Impressive
I will need to read it slowly to digest the details 

[Frank Fremerey]

wow. impressive how much engineering goes into electronics today. The old fashioned lenses were Mechanic and Optics, very fascinating as such. But This? Astounding. I feel computers and roboters made these...

[Ilkka Nissilä]

I don't think robots can assemble these. Nikon use a lot of manual labour in the making of lenses. Tools are used, of course, to make the parts.

[Erik Lund]

Some observations 
Nice to see it's now an optical sensor that convey the zoom setting instead of the old sliding mechanical tongues, they where a thing of the past best forgotten, ridicules easy to beak during service.
Zoom keys seem to be a bit larger that they usually where but some of the front key rollers are not impressive IMHO. so take care not to bump the front of these lenses!
That's also the case for the front threads and hood attachment mount , the lens needs to come apart for even such common repairs,,, expensive to do so repair cost will be very expensive since it is manual labor.
ESD pads, electrostatic discharge protection is another nice touch.
Too many flex cables with contacts for my liking,,, so a new way of connecting things up could be optical 'ring cable' ,,,,
Weather sealing is so so, but sure its better than most
Tape to seal of all openings, to keep 'dust' out is a very cleaver solution, small bits of excess Loctite from all threaded holes etc has apparently been the issue often for even brand new lenses,,, 
Line up markings for all assembly points to aid re-assembly, very nice touch.
Threaded brass inserts for the plastic parts. solid sound design, but a clear cost up, but again great for service and strength id done right. But it does require more space, so design will be larger.

Last but not least; Aperture assembly, long slender blades and all looks like a mechanical engineers wet dream, so beautiful