Problem with over tight trapezoidal nut and X-axis assembly not being parallel to the frame  

Problem with over tight trapezoidal nut and X-axis assembly not being parallel to the frame

hello everyone and I hope you are having a better day than me...

Now lets get to the problems with my cursed build of mk3, and sorry for all my ramblings :/

Left trapezoidal nut got ruined, as with many people, probably because left side of x-axis is much heavier because of the motor, and plastic nut just went into wrong grooves i suppose... so it got toasted when i was trying to turn bot screw rods at the same time... in hindsight, I should have stopped when i met resistance, but yeah, its easy to be smart now.
As per comments in the manuals, I then unscrewed the nut off the assembly, and used heat-gun on threaded rod, and tried to screw and unscrew the nut a bunch of times over the hot threaded rod. That helped a bit, but its still at-least 10x harder to turn than the right nut. so that's still toast.

Now onto the second problem. I have some pictures here.
Right smooth rod aligns perfectly, but then left smooth rod is off by a good 4mm

I could try and first put in left smooth rod and then the right one, but I assume its going to be the same.

Then i've unscrew trapezoidal nuts off, to check alignment without them. So when the right smooth rod is in place, and if i push left smooth rod towards the hole, so that it sits inside the hole in motor mount (its not in the hole, just sits on top of it, i dont want to force it in and bend the rods)... well then check what happens in this picture next:

X-axis assembly goes wildly out of alignment. I did not measure how much, but its alot. see the left printed part touching the frame, and right one has massive gap
(also notice the big old monitor next to the table, that was my weight from frame assembly when i tried to get everything square, 10min step turned into 2 hour step...)

One other person on online manual in comments also had this problem, and this was the response:


When you drop the smooth rods through the bearings on the x-axis should they line up perfectly with the holes in the motor holder? I found that mine were off by 5 mm and needed to push them into place. Is this okay?

pat - 09/12/2018

Hi there Pat, are you sure that your X-axis rods were properly inserted into their plastic parts? This is the only thing which could possibly offset your Z-axis.

Tomáš - 09/13/2018

My X- axis rods are all the way inserted into their plastic parts. My wife helped me with that, because it was impossible to put them in by myself.
We basically took a hammer, and put a bunch of cardboard on 3d printed parts, and hit them with a hammer until they went fully in. I was holding the assembly and she was swinging with the hammer. And yes we were careful not to hit it too hard and not to damage anything.

From what i can gather, is that the 3d printed parts for X axis assembly were printed faulty and now whole x axis is out of alignment.
I've seen this guy have similar problems with x-axis 3d printed part: https://shop.prusa3d.com/forum/prusa-i3-kit-archive--f84/x-axis-is-not-parallel-to-the-frame-t6166.html
I don't even know if I can check that because i probably cant even get rods on x-axis out of 3d printed parts without damaging anything... I haven't tried yet.

Yesterday i contacted prusa support, the problem is that i bought printer from official reseller in Netherlands. So i have to go to them for warranty replacement parts. I would have bought printer from prusa directly but lead time is 2 weeks. And netherlands reseller had them in stock. So yeah theres that.
I contacted the reseller about trapezoidal nut, he didnt reply yet... good this is I can get to his shop in 1 hour by bus. Bad thing is I have this whole other problem about x-axis not being parallel.
I could try and print two x-axis assembly parts with my anet a8 with PLA.... but i bought prusa mk3 so that i will have better print quality and better dimensional accuracy so i don't know if that would fix anything.

its just problems after problems... if I had any idea that it would have been like this, I would have most likely just splurged a bit more and gotten the assembled one. I've been at it for more than 10 hours and im probably not even at 50%.
Its not my first printer either. I have Anet A8 whom i upgraded and tinkered it, a lot. So its not like i have 2 left hands and just cant build a kit.
So far... im not quite happy with how this is going 🙁

I had to persuade my wife that this was going to be a good purchase (its a lot of money), and that I need it because i want to start a home business printing marble machines and that i need prusa mk3 so that later on i can just expand the number of them and get a mini farm going on... (something like OutOfDarts is doing, google him)
I had to write a business plan for her. I wrote 20.1. as a date for printer assembled and 27.1. as a date for printer fully calibrated, so i guess im still somewhat on track...

And its not really an issue that i cant wait a couple of days or even weeks, the issue is that even once i fully assemble it with parts that i have, or with replacement parts, im afraid that it is not going to be as big of an upgrade from anet A8 as i hoped, that i wont have 100% of prusa mk3, but its going to be like 90%... that is why im bummed out and kicking myself in the ass by not buying a fully assembled one.

Thanks for any help guys...