Hello szutsg,
Wow, after all that !
I was contemplating getting the V3 Plus. Looks like I made the right decision not to.
Cheers.
I don’t recommend this printer. Fast and reliable, but you can’t print flat things. 
Beside the Bambu security concerns, i would recommend to buy an A1 or A1 mini instead (for almost the same price). I have the two printer next to each other and the Bambu is a much more refined thing.
Good catch on the belt alignment. I went through the same process as you. I also added washers :).
After moving on from the x-axis VFAs I came to the conclusion that the bed design is terrible. I can get 12k+ acceleration recommendations for the X-axis. Y-axis is <4k with double peaks in the input shaper. That’s worse than my old Ender 3 pro. I spent hours trying to diagnose it. I could tap on the bed and hear rattling. Surprisingly removing the magnetic plate mostly fixed it, but that obviously isn’t a solution. I finally ended up designing custom mounts for the y-axis bearings. That let me add a spring that pushes against the rod and that helps tighten up the bed a bit to get rid of some of the wobble there. It doesn’t eliminate it completely, but it definitely helps. The design of the bed is just terrible and the amount of vibration wrecks high speed printing. It just isn’t possible to get good quality with high acceleration on this machine. The fix might be conversion to linear rail, or converting the bed mount to use 4 bearings instead of the two long ones. Even converting to v-wheels would be an improvement.
I neglected my printer for the last 1 or 2 months but I used it again this weekend for a functional print. I loosen the XZ belts and I printed a rectangle. Belt alignment does not helped a lot on XZ:
the Y surface was fine (almost perfect), the X was horrible.
If i loosen the Y belt i get homing problem recorded here: https://www.youtube.com/watch?v=SINFvR_Mjh0
Hi, I have the same problem on Ender 3 v3 Corexz, did you find a solution?
The best you can do is loosen the belts and print at least 200mm/s on outer walls. The XZ belts can be loosened completely. The Y belt is up to you, but if you loosen it too much the belt can jump off the gear at high speeds.
thanks sleewok
I am printing at 300 and the quality improves, the problem is that I cannot print everything at high speeds. for example when I want to print normal PLA.
Before the ender 3 v3 I had an ender 5 and the quality was much better.
I even tried to print normal PLA at 30 mm and the problem is always present.
Could it be a printer design problem? or engine quality problem.
PS: google translator
I really speak Spanish, sorry.
@CREALITY There are several of us with the same problem, could you solve it?
I have the same problem. I removed the motors, one was hard to turn. The lid was not level. I need to center it. And it became much better. Check it! I will probably change the motors
Tienes fotos de como mejoró ?
Could you send photos of how it improved?