Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?  

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

you could watch the printer like a hawk, as you approach the desired height, slow the print speed, to say 30%

then choose change filament from the front panel menu, follow the instructions and dont forget to hold the extruded waste as you restart the print, this will pull off the dribble as the printer restarts

regards Joan

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

Not the most user friendly option, but with the Slic3r 1.38.5, you can now use the custom layer change G-code for that purpose. For example, the following line will trigger the color change action when changing to Z=5.2:

{if layer_z==5.2}M600{endif}

There may be an issue with numeric rounding, so it is safer to formulate the expression like

{if layer_z>5.19 and layer_z<=5.21}M600{endif}

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

you could watch the printer like a hawk, as you approach the desired height, slow the print speed, to say 30%

then choose change filament from the front panel menu, follow the instructions and dont forget to hold the extruded waste as you restart the print, this will pull off the dribble as the printer restarts

regards Joan

I'm doing it this way exactly right now. This method is, well...

Editing the gcode is easier and quicker.

Not the most user friendly option, but with the Slic3r 1.38.5, you can now use the custom layer change G-code for that purpose. For example, the following line will trigger the color change action when changing to Z=5.2:

{if layer_z==5.2}M600{endif}

There may be an issue with numeric rounding, so it is safer to formulate the expression like

{if layer_z>5.19 and layer_z<=5.21}M600{endif}

That's interesting.
How does this cope with Z-Hop? Since for example Z-Hop goes to the same layer multiple times,. so this script above should be triggered multiple times on the same layer.

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

I found that editing the gcode is very simple indeed. See https://shop.prusa3d.com/forum/print-tips-slic3r-settings-kisslicer-model-repair--f12/how-can-i-program-a-filament-change--t12528.html

Maybe not on Windows OS, the text editor does not want to use 'wrap' and it all ends up as one long line of gobbledigook.
The Ubuntu gedit editor makes it very easy, but I don't know if you can use that in other OSs.

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

I found that editing the gcode is often not as simple.

When z-hop is active, you have multiple lines of G1 Z2.0 for example if you have z-hop enabled and you want to change the color on layer 2.2mm.
Z-hop hops around multiple times at G1 Z2.0 and G1 Z2.5 and back again.
There's a big chance you pick the wrong place to put in the color change command, especially for newbies.

For layer height = 0.2 you'd need to pick the first layer above the height you'd want, like looking for the first instance of Z2.200, and add the code just before it.

There should be an extra field in Slic3r like in Simplify3D where you can define something that does x at height z.

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

> How does this cope with Z-Hop? Since for example Z-Hop goes to the same layer multiple times,. so this script above should be triggered multiple times on the same layer.

It should work. The layer change G-code is executed once per layer change, so it will certainly not be emitted multiple times due to the Z-hop. I did not test it myself yet though, I am out of office, enjoying holidays 🙂

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

If you want to manually edit and insert the M600, you can add this to "After layer change G-Code" slic3r option:

; layer [layer_num] - [layer_z] mm

Gives you a comment line each time a layer change occurs that you can search for with your text editor. This has worked well for me.

More good tips in this thread:
https://shop.prusa3d.com/forum/software-f13/color-change-script-broken--t2513.html

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

I found that editing the gcode is often not as simple.

When z-hop is active, you have multiple lines of G1 Z2.0 for example if you have z-hop enabled and you want to change the color on layer 2.2mm.
Z-hop hops around multiple times at G1 Z2.0 and G1 Z2.5 and back again.
There's a big chance you pick the wrong place to put in the color change command, especially for newbies.

For layer height = 0.2 you'd need to pick the first layer above the height you'd want, like looking for the first instance of Z2.200, and add the code just before it.

There should be an extra field in Slic3r like in Simplify3D where you can define something that does x at height z.

Check "verbose g-code" in slic3r and then search "move to next layer" until you find your layer.

If you can write regexp, try something like "G1 ZXX.+; move to next layer" wit XX you layer height

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

Check "verbose g-code" in slic3r and then search "move to next layer" until you find your layer.

If you can write regexp, try something like "G1 ZXX.+; move to next layer" wit XX you layer height

Great, thanks!

I found the 'Verbose' option under 'Print Settings>Output Options" and re-exported the same gcode.
Result: 73MB instead of 53MB size, but every line is now annotated. Much easier to see what is happening where and when this way.

I assume it will not make a difference to printing time, just transfer time to SD card and time to open the file in an editor will be even longer, but it's well worth the wait any time one wants to manually edit the code.

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

Not the most user friendly option, but with the Slic3r 1.38.5, you can now use the custom layer change G-code for that purpose. For example, the following line will trigger the color change action when changing to Z=5.2:

{if layer_z==5.2}M600{endif}

There may be an issue with numeric rounding, so it is safer to formulate the expression like

{if layer_z>5.19 and layer_z<=5.21}M600{endif}

I thought i'd give an update to this, it works great.

What i did is use the 'before layer change g-code' field in printer settings, and put in {if layer_z==2.3}M600{endif} to make a change before it hits layer Z2.3

Thanks again.

I found that editing the gcode is often not as simple.

When z-hop is active, you have multiple lines of G1 Z2.0 for example if you have z-hop enabled and you want to change the color on layer 2.2mm.
Z-hop hops around multiple times at G1 Z2.0 and G1 Z2.5 and back again.
There's a big chance you pick the wrong place to put in the color change command, especially for newbies.

For layer height = 0.2 you'd need to pick the first layer above the height you'd want, like looking for the first instance of Z2.200, and add the code just before it.

There should be an extra field in Slic3r like in Simplify3D where you can define something that does x at height z.

Check "verbose g-code" in slic3r and then search "move to next layer" until you find your layer.

If you can write regexp, try something like "G1 ZXX.+; move to next layer" wit XX you layer height

That is pretty useful, too, thanks.

Re: Whats currently the best option to switch colors mid print on the MK2 other to do it on the printer?

Not the most user friendly option, but with the Slic3r 1.38.5, you can now use the custom layer change G-code for that purpose. For example, the following line will trigger the color change action when changing to Z=5.2:

{if layer_z==5.2}M600{endif}

There may be an issue with numeric rounding, so it is safer to formulate the expression like

{if layer_z>5.19 and layer_z<=5.21}M600{endif}

Using >= oder <= gives me an error in 1.38.5:


!!!!! Failed to process the custom G-code template before_layer_gcode
Parsing error at line 3.
{if layer_z>5.19 and layer_z<=5.21}M600{endif}
^
!!!!! End of an error report for the custom G-code template before_layer_gcode


Plain > or < are ok it seems. Did I miss something?