Building a 3D printer is easy. Getting the details right to build a great 3D printer is hard, as this is where most companies fail. Why?
For example, on this printer, the bed is a three-point mount (two wheels for adjustment at the front of the printbed) and the printer's bed levelling dialogue doesn't show the height difference that needs to be adjusted (which most 3D printers do). It does show how much it needs to be turned, and the bed levelling wheels have 1/8th turn indicators, making it easy to get it perfect.
In short, instead of an arbitrary number like 0.3mm that has no meaning to the user, they tell the user to turn this knob 1/4 of a turn. An instruction the user can follow.
** Why is this so outstanding? It doesn't cost much, but it improves the user experience. Are companies blind to these improvements because the engineers are experienced, or is there a lack of testing during development?**
By the way, years ago I did such a fix/modification myself on a Tronxy XY2 pro by adding indicators on the wheel for 0.2mm height difference so I could convert the number to rotation: https://www.printables.com/model/301670-replacement-bed-leveling-wheel
Screws of the same pitch will generally be pretty consistent regarding their specified pitch. Unless the manufacturer is randomly grabbing screws, and their matching nuts, from a mixed bin there shouldn't be much variation.
I didn't say anything about variation between two screws of the same pitch. There are various pitches for each length/diameter of screw on the market, and some are more common than others.
But this is what everyone else is talking about, because that's what matters in this case. The manufacturer knows exactly what type of thread they used, and the variances within that type are really small, so they can easily tell how many mm of vertical movement 1/8 of a turn is with high consistency.
No, we were all talking about how they use screws of different pitches, as standard pitches vary with diameter, when they could and arguably should use screws of matched pitches. Some moron read my comment on that last bit as a complaint about variations within a batch of screws of a specific pitch, and other morons ran with it.
If you believe I missed the point that screws of the same pitch, regardless of diameter, would move nuts axially(not just "vertically", but in the orientation of the screw itself) the same distance with the same turn incriments, then you have no idea what I was saying or can't be bothered to actually read it.
Imagine me, machining screws on a lathe, as I do, without understanding that its the consistency of the feed screw(or die if using that method) on my lathe that makes it possible. Or that I could switch my SAE feed screw with a metric one to make producing metric screws easier. Or that I could add a 127/100tooth change gear into the mix instead.
Right, I'm the ignorant one here. Machine Fabrication ... its literally in my username, but no, misunderstanding/misreading my comments and throwing garbled versions of them at me because others have done so is more important than understanding the topic at hand.