Constant stops during print for every two/three layers and movement to zero on x,y axis.
 
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Constant stops during print for every two/three layers and movement to zero on x,y axis.  

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elinesev
(@elinesev)
Member
Constant stops during print for every two/three layers and movement to zero on x,y axis.

Printer: Prusa i3 MK3S+

Filament: PLA

Temprature: 205 for nozzle, and 60 for bed.

Speed etc, are as default in Prusa Slicer.

Issue:

I recently upgraded firmware to 3.13.0 from 3.11.0 (using Prusa link 0.7.0),  did caliberate xyz, and first layer calibration just to be sure.

When printing cylindrical objects, every few layers (2 or 3 layers in random) printer stops , moves extruder to zero on x and y, then again starts.

Is this an expected behavior? or is something known in firmware version 3.13?

Why does it try to find zero on x and y often when its printing fine? When does this happen? are there any sensors or nozzle issues that could cause this?

Is there any setting to avoid this from happening (without risking a deformed object from being printed).

 

Posted : 16/08/2023 3:30 am
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Constant stops during print for every two/three layers and movement to zero on x,y axis.

this sounds like the printer is sensing missed steps, (collision detection)
this causes the printer to re home X and Y axis, to re establish the position it should have reached, had the steps not been missed.
the mk3 series printers monitor the current used by the stepper motors (I believe it's called Stall guard)  during operation and estimate when a restriction to movement, causes missed steps (the same process is used for virtual endstops on X and Y axis)

common causes, include:

Nozzle striking printed model
excessive belt tension, 
over tight idler support screws
faulty idler bearings
Overtight Linear bearing clamps
Faulty Linear bearings
DRY linear bearings. (this often happens after assembly as the transport oil (RUST PROTECTION oil) evaporates
cable bundles catching on printer structure or model
Over Extrusion, 
Leaking nozzle

If you didn't lubricate the linear bearings during assembly, or when you received the assembled printer, I would suggest that you do so now. 
https://help.prusa3d.com/guide/maintenance-tips_23200

then try sliding the X and Y axis, when the printer is at idle. the axis should move smoothly with a slight hum, as the stepper motor poles pass the magnet poles, there should be no tight spots, and both directions should offer similar resistance

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 : 16/08/2023 7:36 am
mcad2000 and elinesev liked
elinesev
(@elinesev)
Member
Topic starter answered:
RE:

Thank you much,

I think I may have a Leaking nozzle problem.

If not on the first layer, on additional layers, it forms blobs when it starts a new layer. Not a lot of stringing, but the first point where it start the layer has a blob. it could be that it its it often.

Nozzle Temperature seems to be within the specification 200-215.

My retraction is set to 0.8 (default for PLA) and retraction speed is 35 mm/s.

I am planning on printing out the string test? To adjust temp in each layer and isolate if temperature is the cause.

If adjusting temperature/ retraction and retraction speed does not solve the problem, could it be do with the nozzle?

or could there be any other cause for me to look into?

This post was modified 8 months ago 2 times by elinesev
Posted : 16/08/2023 11:38 am
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