RE: Skewed XY-Plane (Z Rods, Heatbed)
So over the weekend I built my Core One. [...]
It is a real bummer that there is such poor quality at the leadscrews. [...]
I take it that this was also a newly received Core One kit (i.e. you did not have it in storage for a few months)? If so, that would really be disappointing QC on Prusa's part, and apparently a total lack of feedback from their support team to production.
They should have learned from customer feedback in the meantime, and either have established dedicated checks that all three lead screws have the same pitch -- or at least stopped the practice of combining the pre-packaged MK4 motor kits with a separate motor, presumably from a different production lot.
RE: Skewed XY-Plane (Z Rods, Heatbed)
I ordered it Nov 20th during black Friday sale. When they announced the Plus version I hit the button. Received it last week. So brand new. Or maybe a kit which was in stock and they only added the Plus addon. I have to check the calibration sheet when everything was checked...
RE: Skewed XY-Plane (Z Rods, Heatbed)
Today I got the new motors. I printed 3 cylinders with 260mm heigth in vase mode near the leadscrews (left and right front, rear middle). Left and rear were 260mm, right was 261mm. Swapped the right motor and suddenly 260mm are 260mm. So my C1 is fixed. I also ordered some leadscrews (those also run smooth without binding) for my repair stock (we have 7 MK3.5/3.9/4.0 and one XL in the office and also 2 Core one, so it's nice to have some spare parts handy). What I really like is that many (unprintable) parts are similar over the different models.
I will check the Core1 of my colleague after the holidays and may also swap some motors and then I will deal with support and ask for a refund for the "defective" motors.
It is really a nice printer, but such issues with QC are spoiling the experience...