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1 large X shift at specific height  

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ibdimock
(@ibdimock)
New Member
1 large X shift at specific height

I've attempted to print a largish part 2 times now, and there has been a shift in the X axis at what seems to be the same Z-height.

The shift in X was by a different amount each time. Used the same Gcode for both prints, created with PrusaSlicer.

Print 1:

https://photos.app.goo.gl/Vq4gfLz3DzLKY5ybA

https://photos.app.goo.gl/LBtvSonxcABkbMwF8

Print 2 (interrupted):

https://photos.app.goo.gl/fm4gvKBfVSHkiSu48

https://photos.app.goo.gl/oJHRe95ZaEw8Sp6v6

Thanks

Posted : 04/09/2019 2:25 am
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: 1 large X shift at specific height

Hi Ibdimock, 

do you have Z  lift enabled? it looks like the nozzle is catching on the top of the vertical shield...

did the printer report any collisions?

is collision detection enabled?

are you running in normal mode? or stealth?

 

if you cut the model in prusa slicer so that the model starts just below the failure zone, does it still cause a shift?

cutting the model will allow you to test changes more quickly!

(we know the bottom area prints Ok!)

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

Posted : 04/09/2019 2:43 am
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(@)
Illustrious Member
RE: 1 large X shift at specific height

Another reason for crashes or motor stalls is the larger the part the more likely it is to warp and lift.  When they do lift, it can be sudden, and the nozzle will crash into the now high section and stall. And you get a shift.

Even PLA warps.  Increasing bed temp 10c can help hold larger parts like yours. Also, make sure your bed is absolutely clean. With PEI, alcohol is not sufficient, you need to use soap and water.   

Snags can also happen with curl of plastic at places where the overhang becomes extreme - >60 degrees.  Your images suggest either could be happening.

This post was modified 5 years ago by --
Posted : 04/09/2019 2:56 am
ibdimock
(@ibdimock)
New Member
Topic starter answered:
RE: 1 large X shift at specific height

My first print was in stealth mode, however the second one was in normal. The most recent print did not detect any collisions.

I checked the Lift Z, and it is set at 0.6mm.

I seem to had good adhesion to the bed when removing the parts.

I am noticing some curling on the overhanging sections near the shift.

Posted : 04/09/2019 5:48 am
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(@)
Illustrious Member
RE: 1 large X shift at specific height

I've had parts lift the metal sheet away from the magnets before... and had parts warp only in the corners where the entire part wasn't loose but had lifted.  Usually there's a region where the wall looks like mortar on bricks - where it has oozed out sideways.  I don't see any of that on your parts.  Just something to keep an eye out for on larger parts.

Curl is probably the best reason.  I've had parts I had to physically be there and press the curling areas back flat (printing full size rams horns). 

Three or four things that have helped smaller prints: turning down the print fan as the printer approaches the layers with the worst angles;  slowing down perimeter print speeds to minimum; ensure detect bridging perimeters is enabled; increase infill percentage (needed for large area solid infill).  And aligning the part so the worst overhangs that curl face forward has helped.  

Perhaps someone has a better way of dealing with curl and will add their two cents.

 

Posted : 04/09/2019 7:28 pm
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