Need help printing 2 colors on Ender 3 V2

[Haastnooit]

Hi fellow 3D printers I would like to ask the more experienced printers on AF for some help. I am trying to make a print with 2 colors, and have tried different methodes and with both ways I ran in to trouble.

Method 1: was with using the Z offset plug in as shown on YT by Chep.

I made 2 g-code files for each color in the model and gave the second (top) file a Z offset so it would be printed on top of the first print. This works fine with not so tall print (5mm height), but when trying this with 7mm and 12.5mm high prints the nozzle bumps in to the model when moving from home to the print position.

How can I fix this ?

Method 2: I used the post processing menu and altered the g-code with “pause at height” plug in. Paused it on the last layer number of the first color and changed the filament. When the print resumed the nozzle was buried in the first part, it seems to resume printing too low. I did not use the option to redo any layers.

Can anybody tell me why this happens and how to solve this ?

I am using Cura 5.1.1 slicing software

Here is a fragment of the g-code file containing the “pause at height” script

 

[Tex Koder]

What is your Z offset set at currently?

 

[Haastnooit]

What is your Z offset set at currently?

on the machine display you mean ?

 

[Tex Koder]

on the machine display you mean ?

Correct.

Take a photo of it also. (So you'll have a reference point. )

And what temperature do you have your bed set?

 

[Haastnooit]

At the lower right corner on the start screen it says Z 0.00

 

[Tex Koder]

When it pauses for you to change filaments.. Does the heat bed maintain heat or
Loose heat and must reheat the bed before it resumes?

>> Also, are you using stock bed springs or did you mod it with silicone bumper pads??

 

[Haastnooit]

Bed temperature is set on 50 (recently the stock setting in cura changed from 60 to 50). Temp maintains 50 when paused … I think. Did not notice a change.

Below a picture of my start screen and nozzle in autohome position.

When it pauses for you to change filaments.. Does the heat bed maintain heat or
Loose heat and must reheat the bed before it resumes?

>> Also, are you using stock bed springs or did you mod it with silicone bumper pads??

Stock springs, printer is completely stock

 

[Tex Koder]

Take note to see if there's a temperature cycle between filament change and resume print operations..

Since you're still using stock springs, there will be some deviation/flex
IF your bed experiences such a temperature change..

*******

Did you take a photo of the failed print? I want to see how far did the nozzle got 'buried'..
Was it by a lot?

********



To fix your issue right now.
-with either methods -
You need to manually raise your Z offset by-
to 0.15 or 0.22
Just to allow the nozzle to get back to where it left off without crashing into the previous layer. Once it gets going ,you can start to lower it back to down , slowly.

 

[Haastnooit]

Take note to see if there's a temperature cycle between filament change and resume print operations..

Since you're still using stock springs, there will be some deviation/flex
IF your bed experiences such a temperature change..

*******

Did you take a photo of the failed print? I want to see how far did the nozzle got 'buried'..
Was it by a lot?

It is not much ... it looks like 1 mm perhaps ?


[Edit]

Probably less because some of the red material is melted and pushed up and out of the way. I think it starts 1 layer to low.

Also when it moved back over to the print, the nozzle clipped the side of the print. Can it be that the stepper motor is disarmed and the total X gantry was slightly pulled down by its own weight ?

My pause time was 240 seconds, and the extruder is situated on the X gantry so it is being handled when changing the filament. I think it is a definite possibility the X gantry sagged down a bit.

 

[Tex Koder]

Okay.

Yeah, so manually raise your Z offset by 0.22 after you have swapped out the filament and before you resume print.

It should print from there.

Let us know.





( IF, you think it's off my a whole 1mm than you'll need to raise your Z offset by 0.99 or more.)

 

[Haastnooit]

I was right … cause was disarmed stepper motors and sagging of the X gantry during the pause. I changed the selected setting in the picture below equal to the pause time, and this solved the issue. Standard the value is set to 0 … I think the explanation text could be better.

 

[Tex Koder]

I was right … cause was disarmed stepper motors and sagging of the X gantry during the pause. I changed the selected setting in the picture below equal to the pause time, and this solved the issue. Standard the value is set to 0 … I think the explanation text could be better.

View attachment 269765

Excellent

How did the print turn out?

 

[Haastnooit]

Excellent

How did the print turn out?

Print turn out fine (picture below), however I encountered a new problem.

The first position on the second color started with a blob of filament, you can see it on the left object in de lower left corner. I found out that it is caused by the retraction settings as shown in my previous post, I changed the setting back to standard (second picture below) and the blob is no more …

 

[kspitters]

Print turn out fine (picture below), however I encountered a new problem.

The first position on the second color started with a blob of filament, you can see it on the left object in de lower left corner. I found out that it is caused by the retraction settings as shown in my previous post, I changed the setting back to standard (second picture below) and the blob is no more …

View attachment 269793

View attachment 269794

looks great! Nice solve with the disarm timing.

 

[RCbuzz]

Very nice! I may have to try this!