Filament change at layer

[nitro20 1]

Lolololol...all the freakin bs talkin i do..read this..lol..this is what i did..if only i could return about -2xs the layer hieght.... 

[nitro20 1]

Lolololol...all the freakin bs talkin i do..read this..lol..this is what i did..if only i could return about -2xs the layer hieght.... 

[GregValiant 1,246]

See, you've rediscovered Caveman Programming for gcode.  You get to graduate to Gcode Programming 101.

Looking through what you have there you can see that after the M300 you are turning off the heaters and fan and disabling the steppers.  Disabling the steppers is a bad thing because they lose their position (you will see the XY on the screen start flashing).  If you disable steppers, you need to have a G28 to home the printer so it knows where it's at.  That is also a bad thing.  The switches on the axis are crap and aren't very repeatable for positions.  They are good enough when used once per print, but if you home a second time during a print you can get a layer shift of .5mm because of the switch inaccuracies.  You are also printing the purge line for the second print.  Not good.  Since your print is only 7.2mm tall it works, but what if it was 30mm tall?  Crash.  And the second print can't have a brim or skirt either.

So look through the code and see what you can throw out.  You can start with the M140 S0 line and M107 line that are right after the M300.  Throw out the lines that turn off the heaters and disable the steppers.  Throw out the purge lines.  What you end up with is mean and lean, straight and to the point.  Yes, you absolutely need the G92 E404.xxx line to sync the extruder back into what will follow.  You will also need to remember to move in the Z to get above a print before you try to move in the XY.  That will avoid crashes.

Regarding the blob - What you really need is another part on the build plate.  A part that always prints first so your hot end has a place to leave a blob before it goes to work on the real parts.  Maybe a part floating off the build plate higher than your real parts so it needs support, and Cura will always print support first.  The blob ends up on the support.  Kind of a purge tower.

 

[MrWaiCol 0]

I've tried the method in the video. What i don't understand is how the filament colour gets changed. For me, after the pause, I clicked resume thinking the second colour would be cosen. Not so - the print continued with the initial colour. I have a S3 which has two extruders and I thought it would simply stop using extruder 1 and resume at 2. Am I wrong? Did I miss a step in the setup that i followed perfectly?

 

The trouble with the video is that he used 1 extruder and the S3 has two. Seems daft to have to manually remove the first colour and replace with a second - or is that the key? I have spend almost 2 hours researching this and nowhere is there an example of an S3 being used for dual colours. 

[IRobertI 520]

5 hours ago, MrWaiCol said:

I've tried the method in the video. What i don't understand is how the filament colour gets changed. For me, after the pause, I clicked resume thinking the second colour would be cosen. Not so - the print continued with the initial colour. I have a S3 which has two extruders and I thought it would simply stop using extruder 1 and resume at 2. Am I wrong? Did I miss a step in the setup that i followed perfectly?

 

The trouble with the video is that he used 1 extruder and the S3 has two. Seems daft to have to manually remove the first colour and replace with a second - or is that the key? I have spend almost 2 hours researching this and nowhere is there an example of an S3 being used for dual colours. 

Take a look at this video:

 

[MrWaiCol 0]

Already seen that  - it's of no help. I should have mentioned, sorry, that the file I'm printing has the colours in one single stl file. The video you quote has two stl files that merge; I don't have that - hence I don't know what to do.

Edited May 25, 2021 by MrWaiCol
spelling

[GregValiant 1,246]

I played around with this a bit and I think you can change colors at a layer.  It won't be fancy like if there were two models but it would change extruders.

Place a support blocker to cover the model and then adjust the Z to the layer you want the color change.  Set the Overlap Settings to Cutting Mesh.  Set the model to one extruder and the Support Blocker to the other extruder.  I assume you will need a purge tower.

If there is support going up past the lower part of the model, up to the upper part of the model, you need to make a decision on which extruder to use for the support.  The option to change support extruders when getting to the cutting mesh isn't available.  If there aren't any supports to consider, the cutting mesh looked like it works as expected with the lower model printed with one extruder and everything covered by the Cutting Mesh printed with the other extruder.

[MrWaiCol 0]

UPDATE - nailed it.

Used MeshMaker. Cut the image into two parts and imported 2 images into Cura. Chose different filaments for each part. That did it. Thank you for ALL responses.

[Rsm61 0]

I've also been trying to do this (Pause), but I'm wondering why to redo a layer? Wouldn't that add a layer for every Pause?