gyorid print issues

[BobFrakes 2]

With the latest version of Cura it includes the gyroid slicing model that I really like.  It speeds up the printing on my rather slow 3d printer pretty well.  

I found it recently and started using it but lately I may have found an issue.  I created a part that I wanted to print and it printed very quickly using the gyroid on 25 fill.

Since I was prototyping the part i did not include any through holes for mounting the part to another object.  

I then added two mounting holes with a counterbore to recess the mounting screws.  The printer stared losing steps as it got to the hole.  At the same time I wanted it to print faster so I reduce the infill to 10 percent.  

I then reset the infill to 25 percent the reprinted,  The same happened only worse.

The last print I change back to cubic infill and the part printed normally with no step loss.

I've fine tuned this printer very excessively and it does not normally lose steps.  I really don't know if this is a bug in the gyroid code but it seems to be a weird interaction with the stepper motors.

Is anyone having this issue?

 

[GregValiant 1,112]

The gcode tells the printer "where" to send the print head.  It's the printer that determines the "steps" to send to each motor.  Since there is no feedback loop to tell the printer/processor where the print head really is, the printer/processor has to use the number of steps as the location.  If something like belt slippage happens there isn't any way for the processor to know about it so it merrily keeps sending information to the motor.  It assumes that the print head is where it told it to go.

 

Have you opened the Gcode file in Cura?  The gcode reader is separate from the slicer and if there are movement errors they will show up in the gcode preview.

[MariMakes 178]

Hey @BobFrakes,

 

Thanks for your report 👍
 

Gyroid is a type of infill that introduces a lot of smaller segments. 
You could be seeing a form of buffer underrun. 
It would help if you could show a picture of what you've been seeing. 

[GregValiant 1,112]

Good call @MariMakes.

@BobFrakes what printer are we talking about here?  Are you printing via SD card, Octo, USB...?

[BobFrakes 2]

Turns out that the two rods that the print head slides on were loose and one even came out of its bracket.  Once I tightened them the loss of steps seemed to disappear.

[GregValiant 1,112]

Ah.  It was Murphy.