Layer shifting + Later: Fixing Z-Wobble

[Mayus]

Hello everyone,
I recently built a Geeetech i3 Pro B. Very nice printer, almost no calibration needed. After a few prints I recognized a big X-axis-shift. I tried every single fix I could find in the internet but with no improvements. Here are some photos:
https://imgur.com/ECzSnO7
https://imgur.com/ambtjHK
https://imgur.com/FVXspuX

I've another question: How do I have to change the slicer settings to get a smooth first layer? At the moment you can pull off some strings from the first layer:
https://imgur.com/xHq5ZH9

Thank you in advance,
Marius

[Gingko]

For layer shift:
You can check the voltage of A4988 of X-axis.
Also the belt of X-axis, maybe it's loose.

For the first layer:
I think you can try to relevel the bed, the nozzle is probably too far away from the bed and the filament cannot attach firmly.

[Mayus]

Hi!
Thank you for your reply. In the meantime I fixed the layer shifting problem. I recognized that the extruder was very hard to move on the smooth rods but I put some vaseline on them and now everything just works fine.

The bed was also leveled quite good and the first layer is now flush but you can see the lines anyway and you can rub them off easily. I hope there's a fix for this. Also, the last layer of an 3D object has holes in it. How to fix that? I 've increased the top layer density and height already.

Thank you in advance

[_kaktus_]

Hi


If vaseline oxidizes over time, it is not a good solution.
Now it is fulfilling its purpose, but in a while it will be quite the opposite.
It will inhibit movement.

I immediately say WD40 is not suitable either. For the same reasons.


I use professional oils, for guides, used in large CNC machines.

[Mayus]

Hi, thank you for your reply
I don't think that Vaseline oxidizes, but I will replace the Vaseline with sewing machine oil, this seems better. What can I use for the threaded rods? They make a terrible noise when moving the Z axis.


TYIA

[_kaktus_]

Haaa
Now I'll tell you some stories, it's quite new.

For some time now, during the operation of my printer, I have been observing the occurrence of nasty vibrations while driving my head carriage.

During a private conversation with my friend, I noticed that Geeetech gives mechanical components of too low quality, thinking that vibrations and noise are the result of too fast wear of the plain bearings. Or linear guides, on which you could see traces of driving and rubbing off the balls in the bearings.

So I bought new linear bearings and then high quality stainless steel linear guides.

The new components had a completely different quality. They matched each other more precisely. And what is important for me, they were not expensive to buy.

To my surprise, these unwanted vibrations came back again after the mechanism had been running for a short time, and the printer was making excessive noise during operation.

Then I started to hold my finger on various elements. Of course while the printer is in operation.
It was aimed at finding a source of vibrations which are easily transferred to the entire mechanism.

Of course, I had to return the honour to the manufacturer and withdraw my bitter words from him. (In private conversation)

It was easy for me to find a source of vibration. They are generated by clearances in the upper bracket of the linear guides. The trapezoidal screws themselves do not generate much vibration during operation.

Of course, this is what is happening in my case.

The solution?
I have inserted a few drops of professional oil into the plastic holder of the linear guide.
Because the oil is quite dense and sticky, it filled the gap perfectly and prevents the formation of vibrations during the operation of the mechanism.
I regard this as an ad hoc, temporary solution.



I greet you very warmly.

[Mayus]

Hi again
I just want to give a quick update.
The Layer shifting still remains.
I think I'm going to swap the smooth rods with something that is indeed smooth
And I'm going to replace the threaded rods with lead screws since threaded rods are clearly not made for moving parts, while lead screws are.

I already have replaced the standard extruder with a cheap E3D bowden clone from Amazon. It's waaay better and I can recommend this to everyone.
By the way, I used these parts to fix the extruder on the geetech extruder carriage: https://www.thingiverse.com/Mayus/colle ... esserungen


When I have the replacement parts, I'm going to post an update here asap.

Kind regards,
Marius

[Mayus]

Quick update!
I haven't ordered the rods yet, but I solved the problem with the layer shifting!
All I had to do is a software update

The recommended firmware is soo old, and I found this firmware someone from the forum configured: https://www.geeetech.com/forum/viewtopic.php?t=61011

The result:
https://imgur.com/hNtljsh
I know, there is some Z wobble there and I think I can't fix it without other rods.

See you again when the rods arrived!

[_kaktus_]

Hi


Bravo for independent work.

[Mayus]

Alright, another update!

The rods aren't there yet.

I printed some anti-Z-Wobble brackets, like this one: https://www.youtube.com/redirect?redir_ ... y%2F1iWOMo

Now I have a problem: The wobble bracket lets the z-axis sit on top of it.
But now, I have to compensate the height of the bracket.
I already tried to higher the printing bed. But it's not enough and I don't know how to compensate that difference.

Thank you in advance.