CityZ

If you are using the Anycubic switch, it might be wired differently than the Flsun version. If you look inside the sensor at the switch itself, there’s pins for normally-open (NO) and normally-closed (NC). The wire going to NC needs to be moved to NO.

On the control board, the wires need to go to Ground and Signal for the Z-min plug. Do not connect to the Voltage pin.

The “Leveling_sw” button adjusts the offset needed to use the leveling switch. (The offset is the distance between the nozzle and the bed when the switch is pressed.) There’s another Z-offset button that sets it to the default offset for using the leveling pad. You have to push the appropriate offset button before engaging the leveling option.

The QQ doesn’t have manual leveling without changing the Gen L board firmware to a different Marlin version.

No hints? It shows you that it's fastened together with screws, and shows where all the screws are. You just needed to figure out how to access them all.

To add a bit, consider a scanner that projects a line onto an object and records that with an offset camera. Imagine that the projector is on the left, the camera is on the right (both pointing away), while the line is projected up and down. In this case, the shift of the line to the left or right directly corresponds to how far away it is from the scanner. Where the line projects onto something close, it is shifted to the left, and where it projects onto something far, it is shifted to the right. This setup works great, except that it only gives you one stripe's worth of data. You need to scan it across a scene to get the whole picture.

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This setup is doing the exact same thing, except instead of projecting a line, it is projecting a dot pattern. By measuring the displacement of each dot, it can figure out how far away it is from the camera. The dots are arranged in a special pattern so that the logic can tell one from another. Since the dots cover the whole scene, you don't have to scan it.

What is the connector near the bottom of the case (right hand side) for?

They don't mention such details in teardowns, but rather in repair guides.

The back of the logic board faces the back of the machine, so a door would work. I suppose Apple just thought that aesthetics were more important than upgradability.

Citazione da Robk732:

I broke most of my clips taking it apart. Are these clips for sale? It seems the only way to take it apart is to break the clips, then replace them before putting it back together

They seem like they'd be easy enough to replace with some bent pieces of plastic with a hole made in them. Perhaps the plastic from a DVD case might do the job.

Looking at some of the close-ups in iFixit's official tear-down, I would tend to believe that the back is die-cast and then a bit of additional machining is done to it. The additional machining is at least the under-cutting around the perimeter to form a lip, plus a deepening of this lip where the clips are. Check out the close-up in step 25. You can see a difference in textures.

It's worthwhile to note that Apple claims to machine the MacBook [Pro] cases out of a solid block of aluminum, and that they have a similar finish as the iPad on the inside. Of course, Apple may be taking some liberties with the truth, in that the "solid block" may start out as a die-cast part that is not too far from the final shape.

In any case, I think there's no question that the iPad case was designed on a computer and that a CNC machine produced an original from which the production parts are based.

If Apple were more pro-consumer, they could engineer their products to be more water resistant. Instead, it almost seems as if some of their products (the notebooks) are designed to be damaged when spilled upon. A moisture barrier under the keyboard would've saved many headaches.