Longtime lurker willing to enter 3D

[Artur5]

In case you bothered to read my initial woes with the Prusa, i3Mk3S+ ( see the thread 'Cat toys' in the subforum '3D printed project showcase' ) you can skip the rest of this post. In case you bothered to read it, probably you'll prefer to skip it as well.


Good news :
-Kit arrived. -Kit assembled. -First self tests OK.
-Bad news : -Z axis calibration (last self test ) failed

The machine didn't refuse to print but no way to get anything right.
Filament wasn't layered smoothly into the hot bed but 'dropped' by the nozzle at some height above the hotbed. Results: it wouldn't stick at all but it was miserably dragged along the hotbed hanging from the tip of nozzle.
Technical advice from Prusa wasn't of much help. They insisted that I needed to adjust properly the height of the proximity sensor. I did it, but that wouldn't correct the problem, no matter how high or low I relocated the proximity sensor.
-My uneducated opinion is that the 'root of evil' was the failed Z-axis calibration during the self tests. Thus, the proximity sensor couldn't work as intended.

Option 1 : return the machine to the manufacturer and let them do the job properly.
Prusa told me that I'd have to wait at one month or more for having the repair done. As this seemed a rather long wait I decided to try again for myself. ( option 2 ):

Option 2 : Total disassembling of the printer and rebuild again from scratch.
So I started to do, but an accident happened : one 3D printed part was cracked in the process. It's one of the parts holding together the rods of the X-axis. Once you stuck that component into the rod, it's no't easy to remove it unharmed (specially if it's made of plastic with 0% infill). It could be glued with cyanocrilate but this is a critical part that needs to be perfect and solid. The slightest misadjustment would compromise the rigidity and accuracy of the X-axis. No way I could be confident in a glued part. Therefore I ordered a new one. They come in sets of two (one for each side). The parcel has been shipped alreay but I expect that, with Easter in the way, it will take one week or more to arrive. Patience is the word.
In the meantime, I reassembled the parts that doesn't need that cracked piece. Now let's await the arrival of the slow truck from Bohemia.

 

[The Hat]

When you get her back together again, just skip the auto leveling adjustment and do it manually yourself.

Home the bed and extruder nozzle, and disable it, then move the head by hand to each corners of the bed and adjust the levelling wheels until the nozzle is snug on a piece of 80 gm, paper, don’t for get to do the centre also..

I have two printers that have the auto levelling, but prefer to do it by hand myself, less likely to fail..

 

[Artur5]

Well, the machine did that automatically during the first self tests. It spent a good 10 minutes 'tap dancing' over the paper sheet in every corner No errors happened then. The problem came later with the Z-Axis calibration where the extruder is raised at the top and lowered again. For some reason, it failed. I guess it was a geometrical unbalance between the horizontal x-y plane and the vertical Z axis. I tried relocating slightly the vertical rods and the holders of thr Z-motors, but no luck.
Anyway, I don'to think that the Prusa allows a manual calibration; there're no calibration wheels.



P.S:
The last words of my former post ( 'slow truck from Bohemia' ) were intended as a cue for @stratman.
I'd thought that he would jump at it ,. but no luck here either.

 

[stratman]

'slow truck from Bohemia'

Not familiar with that phrase.

Is that what Maynard G Krebs drives?

 

[Artur5]

I expected you'd post a video or something about Queen's Bohemian Rhapsody ..

 

[Redbrickman]

@Artur5 - I'm sure you have already seen this but there is a complete assembly series here

https://help.prusa3d.com/en/category/original-prusa-i3-mk3-kit-assembly_336

I'm not familiar with the Prusa or could have helped you more. If it's any consolation I built a printer from scratch and I know how it is when trying to figure out all the steps.

This was the wiring nightmare before I got it all finished... and believe it or not it actually worked, with one small fault where the extruder motor cables where not coloured coded correctly at the factory so it didn not want to play at first.

Stick with it and go slow and read and re-read each step of the part you are at, as we want to see you become a 3D hermit like the rest of us

 

[The Hat]

I expected you'd post a video or something about Queen's Bohemian Rhapsody

.....

 

[stratman]

Should have known you EU guys not knowing an iconoclastic 1960's American sitcom character.

Bohemian, to me, means 1950's beatniks, finger snaps clapping to poetry readings, bongos, and Greenwich Village, Manhattan of the 60's.

 

[Artur5]

@Artur5 - I'm sure you have already seen this but there is a complete assembly series here

https://help.prusa3d.com/en/category/original-prusa-i3-mk3-kit-assembly_336

I'm not familiar with the Prusa or could have helped you more. If it's any consolation I built a printer from scratch and I know how it is when trying to figure out all the steps.

This was the wiring nightmare before I got it all finished... and believe it or not it actually worked, with one small fault where the extruder motor cables where not coloured coded correctly at the factory so it didn not want to play at first.

--

Stick with it and go slow and read and re-read each step of the part you are at, as we want to see you become a 3D hermit like the rest of us

Thanks @Redbrickman.

Yes I have the assembly manual. Prusa includes a copy in paper with the printer. It’s better though to open the .pdf file on the computer, because you can enlarge the images much more, and, believe me, you need that.

The most irritating aspect is that, after many hours, I succeeded ( apparently ) in assembling everything OK. The printer started up without problems, the LCD screen gave me a polite welcome and, after the first self tests, even congratulated me for a perfect perpendicularity of the X-Y axis and then the naughty thing refused to calibrate the Z axis without more explanation than “Z-axis calibration failed. Please fix the problem..”
They say that this Prusa is a smart machine, Too smart sometimes..

Nevertheless, second time is easier, even the extruder assembly isn’t really difficult if you take your time. The most challenging and nerve shattering part is the internal cabling of the mainboard. They have designed a case so absurdly small that it’s a nightmare to connect, fit and route all the cables inside.

 

[The Hat]

It’s better though to open the .pdf file on the computer, because you can enlarge the images much more,

Give us a Feckin look at your new baby..
@Redbrickman shows what he has underneath..