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First layers in X are Shifted  

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SteveA
(@stevea)
Active Member
First layers in X are Shifted

Hello. thanks in advance for any advice you may offer.

On some of my prints the first few layers in X are "shifted", then they revert back to spec. It doesn't happen every time. Thoughts?

Veröffentlicht : 18/10/2020 9:24 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: First layers in X are Shifted

Hi Steven,

could you save the project as an MF3 file, then zip the file and attach it to a post, so that we can have a look Please

Regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Veröffentlicht : 18/10/2020 10:22 pm
SteveA
(@stevea)
Active Member
Themenstarter answered:
RE: First layers in X are Shifted

ChampagneLightShort

 

Here you go, and thanks!

Veröffentlicht : 18/10/2020 11:29 pm
Area51
(@area51)
Mitglied
RE: First layers in X are Shifted

I would test if the x-axis pulley is secured on the motor shaft and the belt has the right tension.

As @joantabb suggests an upload of the zipped project will help finding slicer/model problems.

Have a look at my models on Printables.com 😉

Veröffentlicht : 18/10/2020 11:32 pm
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(@)
Illustrious Member
RE: First layers in X are Shifted

A couple of things about that model: Are you intentionally trying to print at 0.05 mm? The number of vectors in the file are, well, exceptionally large, and probably 10x overkill for acceptable resolution: I'd try reducing the vector count or simplifying the model.

You mention you see this shift with other models, too. Almost always, when a layer shifts, some part of that axis is dragging with too much friction.  Are you printing in Stealth or Normal mode?  How large is the shift?

A photo of a part that has failed, on the print bed, will be more informative than the model you uploaded.

Veröffentlicht : 19/10/2020 4:56 am
SteveA
(@stevea)
Active Member
Themenstarter answered:
RE: First layers in X are Shifted

@tim-m30

Sorry, I've been on a business trip.

I'm always printing these at draft quality (.3 or .35mm layer height, and in normal mode). I'll have to print another to give you the view you'd like. I see what you're saying with drag but it occurs exclusively in the first few layers then prints properly. Wouldn't the drag affect other layers, too?

 

Veröffentlicht : 23/10/2020 9:45 pm
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(@)
Illustrious Member
RE: First layers in X are Shifted

If you are using a 0.4mm nozzle, 0.35 layers is not going to work very well. 0.32 is pushing the limits of the nozzle. 

Veröffentlicht : 24/10/2020 3:02 am
SteveA
(@stevea)
Active Member
Themenstarter answered:
RE: First layers in X are Shifted

@tim-m30

Thanks for responding but I'm using a .6 nozzle.

Veröffentlicht : 24/10/2020 1:07 pm
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(@)
Illustrious Member
RE: First layers in X are Shifted

My apologies - the file you gave for us to review so we can help are all defaults, and show you are using a 0.4mm nozzle at 0.05 mm layer height.

I guess I'll leave the conversation. Good luck.

Veröffentlicht : 24/10/2020 7:00 pm
SteveA
(@stevea)
Active Member
Themenstarter answered:
RE: First layers in X are Shifted

@joantabb

Hi Joan! Any results you can share?

Steve

Veröffentlicht : 24/10/2020 7:01 pm
SteveA
(@stevea)
Active Member
Themenstarter answered:
RE: First layers in X are Shifted

Better representation than previous photos.

Veröffentlicht : 24/10/2020 7:08 pm
JPLau001
(@jplau001)
Eminent Member
RE: First layers in X are Shifted

From your last set of pictures it looks like you have a loose in your mechanicals on either your X-axis or Y-axis.

I'd check:

  1. your heatbed for "slop" movement in the X-axis direction.  The heatbed should only have free movement in the Y-axis direction; any free movement in the X-axis direction needs to be corrected.
  2. your y-motor pully  has both grub screws reasonably tight.

    One grub screw must be tight and perpendicular to the "flat" in the Y-motor's shaft and the second grub screw should be tight against the curved part of the shaft as per "Step 32 Assembling the Y-motor pulley" https://help.prusa3d.com/en/guide/2-y-axis-assembly_25488#26888 onwards.  Having the grub screw on the "flat" loose will allow the pulley to rotate slightly on the shaft instead of being fully fixed to the stepper motor's rotation.

    Warning - overtightening these grub screws can damage the screws or the motor pulley.

  3. your x-motor pully has both grub screws reasonably tight.

    Again one grub screw must be tight and perpendicular to the "flat" in the X-motor's shaft and the second grub screw should be tight against the curved part of the motor shaft as per "Steps 8 and 9 Assembling the X-axis motor pulley" https://help.prusa3d.com/en/guide/3-x-axis-assembly_27464#27800 .   Having the grub screw on the "flat" loose will allow the pulley to rotate slightly on the shaft instead of being fully fixed to the stepper motor's rotation.

    Warning - overtightening these grub screws can damage the screws or the motor pulley.

  4. check that both the X and Y axis belts, rods, and pulleys are clear of debris and dirt; clean as required and clean and lubricate the rods as per Prusa's maintenance guide.
  5. check that the cables to the Heatbed, the x-axis, and extruder all have free and clear movement. The cable movement for the x-axis and extruder will also need checking for all Z-axis heights.   

 

Veröffentlicht : 25/10/2020 8:33 am
SteveA
(@stevea)
Active Member
Themenstarter answered:
RE: First layers in X are Shifted

Thanks, Jonathan.

Preliminary results are that the solution was #3. I did find one of the set screws loose. Tightened it, then printed - layer shift was gone! I'll have to do a few more for 100% victory but I'm confident this was it. In case I'm right, I thank you and to all who contributed.

 

Veröffentlicht : 26/10/2020 12:10 am
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