From what I have read in this thread, there is a good reason for kit printers.  One benefit of kit printers is the feedback from those that assemble the printers and point out little things that they find.  Things that pre-assembled printers will run into due to shipping, temperatures, who know what before being used.

Pre-assembled printers need to work 100% of the time.  Need to have a way to confirm this.  It should never be to a point that a customer wants to return an assembled product within days of receiving the product.  That is a major issue for both the customer and the supplier.

I design and build custom systems and the amount of time that I have to take for each project is expensive.  One benefit that Prusa had from kit sales was feedback on the issues that is very beneficial to any manufacturing business.  Information that is far more valuable than any in-house experience.

I have set aside the money for a Core one L with the INDX head but waiting for the kit version, or 6 months after release.

Personally I would also be in the camp of "let's iron out the kinks together, I will keep the printer and learn something in the process". I was in that spot, and reached that conclusion, during my 60-day window in April/May of last year -- when the Core One (and the kits in particular) still had quite a few rough edges.

But Prusa specifically advertises the Core One L as "prints right out of the box, no calibration needed!" (Let alone any maintenance.) So Prusa have to be prepared for customers who take their word for this and buy the printer because they just want to print, not fiddle with the machine.

Posted by: @simmania

I measured the belt tension and it was to low. Didn't expect this to be so easy with the Prusa app that just measures the resonating frequency. I adjusted the tension (also very easy).

Homing seems normal now. Nozzle cleaning is done in a few touches. And Bed leveling is quicker, though some times it needs 2 or 3 probes per point. So I think issues 2, 3 and 4 may be solved. 

Not sure about the y-motion sound yet. Will do some prints today.

Did not expect to need to do this kind of measurements and adjustments for an assembled and tested printer. But it was very easy to do. So I think Prusa should add this to the the procedure to get started.

The messages above about shipping problems do scare me a bit. Because these loose belts may indicate bad treatment during shipping. I hope there are no other things wrong with the printer. What things would be wise to check?

Belive me ...you/we don't want to know what happens to our shippments sometimes - and I mean this in general, not releated to any shipping company/freight forwarders...eg. dropping a shippment/box like the Core One's on a flat side of the box, not on a corner/edge...you will not see anything from outside...

From my point of view:
I understand and I am with you when thinking "hey, this is a factory assembled device...it should work "out of the box"...". Depending where you live you maybe have some "extended" consumer rights, like we have here in the EU. Yes, you could demand to send it back, but this only works with Prusa, meaning Prusa has agree to it.

Or... you look at the bright side having a Prusa printer and do (you already did it) what you should do regularly right at the beginning: Full calibration routine including lubricating the rails, like you would do it after assembling the printer.

Afterwards you know the status of your (factory assembled) printer and you can "discuss" some issues with Prusa support. Maybe you both - you and support - can solve the issues without returning the printer and you have a functional printer after it.

When you reached the point that everything is working as it should be, you then can bring up your thoughts to support - "...ok, as the printer works after some adjustments/parts replacements now, I would like to point to the fact that I was not expecting this from a factory assembled printer...". Depending on what you and support did togehter to reach this point it depends how support is able to fit this in the matrix - "problem solved...no return (= costs a lot of money)...yes, there were some problems maybe related to assembling/shipping...let's offer him a coupon to compensate for the inconvenience...".

But, this are only my thoughts...

One of the noticeable traces was the fact of the uneven z screws with uneven screw length in some Core One Kits.

  they are ISO9001 certified i'm pretty sure traceability is a part of this.

In my experience, ISO 9001 essentially means: I can prove that I did things the way my process says they should be done. It does not guarantee that you have a great process. 😉

I mean, has anyone "traced" the ESD-related crashes and ensured that the XY motors get properly grounded? It sometimes feels like tech support, R&D and manufacturing are on opposite ends of the Prusa building. And it's a large building!  

Posted by: @jurgen-7

 

Do we know whether Prusa actually does this? 

I think they should, they are ISO9001 certified i'm pretty sure traceability is a part of this.

  they can then backtrace it to the batch numbers of the parts and people that were assembling them.

Do we know whether Prusa actually does this? 

If you report it then it may help others as well.

Posted by: @simmania

I measured the belt tension and it was to low. Didn't expect this to be so easy with the Prusa app that just measures the resonating frequency. I adjusted the tension (also very easy).

Homing seems normal now. Nozzle cleaning is done in a few touches. And Bed leveling is quicker, though some times it needs 2 or 3 probes per point. So I think issues 2, 3 and 4 may be solved. 

Not sure about the y-motion sound yet. Will do some prints today.

Did not expect to need to do this kind of measurements and adjustments for an assembled and tested printer. But it was very easy to do. So I think Prusa should add this to the the procedure to get started.

The messages above about shipping problems do scare me a bit. Because these loose belts may indicate bad treatment during shipping. I hope there are no other things wrong with the printer. What things would be wise to check?

I wouldn't worry too much. With lack of belt tension, the belt settling in seems more likely than shipping damage. I can't think what should happen so belt tension drops without being obviously bent and broken. And belts do stretch over time. Most likely, the belts weren't attached properly, and you fixed that already.

What you should check is that Z axis spindles match pitch. Otherwise the print plate tilts over its Z travel, and that cannot be compensated in software.

If you have a digital spirit gauge (angle meter) just put it onto the print plate and watch it change running up and down (two runs - once between first and second spindle, then e.g. between second and third spindle).