Special mode - one at a time: printhead to center at every new layer

[Amazon62 3]

Hi there,

 

First time here (beside Thingiverse), so nice to meet you!

 

My question/problem is a bit difficult to explain, but I'll try. 

 

When I print multiple parts with the setting 'Special Mode - Print Sequence - Once at a time', the print head will move to the center of the bed after each layer. This only happens with the first part. Why is it doing that and how can I change it so it won't happen? 

 

The advantage of 'Once at a time' is that there is no stringing between parts (especially with PET-G), but now it will sting to the center of the bed with that first part.

 

Thanks!

[fvrmr 73]

Can you also see this movement in the preview tab?

Could you maybe share your project file? 

[GregValiant 1,251]

In Experimental there is "Wipe Nozzle Between Layers".  

[Amazon62 3]

Hi there,

 

Sorry that my respond is a bit late. I didn't get a notification in my email somehow.

 

Attached is the g-code of the file. Wipe nozzle is not checked btw.

 

Thanks!

CE5_ring half.gcode

[GregValiant 1,251]

I don't think that's the same gcode file.  To troubleshoot gcode files I read them into AutoCad to take Cura out of the loop.  The problem moves aren't in the gcode.

Can you double check that you posted the correct file?  It would be extremely odd if the printer just decided to go somewhere by itself on every layer change and then return to printing.  I have no idea how it could do that.  That looks like an Ender 5 and the motherboard and firmware are close enough to my Ender 3 Pro that I'm pretty familiar with it.

 

Here is a screenshot of the file in AutoCad.  Every line in the Gcode file is there.  Travel lines (G0 moves) are magenta and you can see that there are only a couple of them that cross over between the parts.  There is no running back and forth to the centerline of the build plate.  This is exactly the same as it looks when opened in Cura.

 

 

 

 

[gr5 2,173]

I think maybe there is a feature in Marlin (on your creality printer) that moves the head away from the print and triggers a digital signal - the idea is to take a photograph after each layer to make a stop motion video.  I'm thinking you have that feature enabled on your printer.

 

[gr5 2,173]

I should say that I've also seen strange movements similar to this - with all axes except Z (because Z movements are extremely rare in gcode compared to the other 3) - where it reads a bad gcode from the SD card randomly and it changes one of the digits in the movement and may move for example exactly 100mm in X or Y or E.  Then it goes back and continues where it left off.

 

The fix is typically to take apart the SD card reader and clean it with isopropyl alcohol.  I found a small hair - like an eyelash - in my SD card reader.  After removing the hair the problem still happened but about 100X less often (once every 5 hours instead of once every 2 minutes).

 

Does it always move to the right?  Towards the center?  Or does it sometimes move Y axis and sometimes just move the extruder a long ways (like the printer stops moving for a few seconds while it unextrudes and re-extrudes).

 

[Amazon62 3]

17 hours ago, GregValiant said:

I don't think that's the same gcode file.  To troubleshoot gcode files I read them into AutoCad to take Cura out of the loop.  The problem moves aren't in the gcode.

Can you double check that you posted the correct file?  It would be extremely odd if the printer just decided to go somewhere by itself on every layer change and then return to printing.  I have no idea how it could do that.  That looks like an Ender 5 and the motherboard and firmware are close enough to my Ender 3 Pro that I'm pretty familiar with it.

 

Here is a screenshot of the file in AutoCad.  Every line in the Gcode file is there.  Travel lines (G0 moves) are magenta and you can see that there are only a couple of them that cross over between the parts.  There is no running back and forth to the centerline of the build plate.  This is exactly the same as it looks when opened in Cura.

 

 

 

 

 

Hi, 

 

Thanks for the effort! I reproduced the G-code with special mode 'one at a time' checked, but when I open the G-code it does not show that special mode in the preview! So the G-code is correct, but not showing correctly in Cura. When I slice it and then check the preview, it does show, but not the movement to the center.

[Amazon62 3]

15 hours ago, gr5 said:

I think maybe there is a feature in Marlin (on your creality printer) that moves the head away from the print and triggers a digital signal - the idea is to take a photograph after each layer to make a stop motion video.  I'm thinking you have that feature enabled on your printer.

 

 

Hi,

 

I checked the printers menu, but I can't really see something. I checked in sub folder 'motion', but can't see an option that could trigger this.. Btw, I use Pi4 and octoprint, so not from SD card. Maybe I can try to print directly from the printer SD and see if that makes a difference. Maybe octoprint causes this?

[Amazon62 3]

Well, I just printed directly from the printer and now this problem does not occur. So I think Octoprint is to "blame".

Need to dive into that...

[Amazon62 3]

15 hours ago, gr5 said:

I think maybe there is a feature in Marlin (on your creality printer) that moves the head away from the print and triggers a digital signal - the idea is to take a photograph after each layer to make a stop motion video.  I'm thinking you have that feature enabled on your printer.

 

Maybe you are partly right then, but need to focus on Octoprint instead of the printer. Maybe octolapse is to blame (causes more problems to be honest). 

 

Edit: Well, problem solved! I disabled Octolapse and it does not go to the center everytime. This it is indeed for the timelapse (stop motion), to keep the printer head from moving in the timelapse video.

 

Sorry that I didnt mention the use of Octoprint before, maybe it could saved us some discussions. Anyways, many thanks for the assistance!!

Edited May 27, 2021 by Amazon62

[fvrmr 73]

Glad to hear that you've found the problem!

[gr5 2,173]

Octolapse!  Cool.  I just learned something.  The next time someone has this problem I'll ask if they are using Octoprint!

[GregValiant 1,251]

Ya gotta love it when everybody was right!!🍻