SOLVED Why is my UM3 continuously printing the wrong material?

[Grasmier 0]

Hi,

I'm getting quite frustrated after 3 days and keep blaming myself but I've run into a dead end after 8 reprints. The problem is that my prints keep getting out fully printed in PVA (Extruder 2), while I clearly indicate in Cura that is should use PLA (Extruder 1). In Cura it says: "Print Selected Model with Extruder 1", see screenshot 1 below.

I'm using:

- Cura 3.0.4.

- UM3 latest stable version (the display says I have the latest update).

- Windows 10 PC

1: In Cura I select my model and press Extruder 1. The object appears in the color of Extruder 1

2: This is how my filament is placed. It's fed into Feeder 1 and 2 appropriately

3: This is what the Ultimaker is printing. A brim in PLA (Feeder 1) and the support + object in PVA (Feeder 2 and Extruder 2). You can see the nozzle is active for printing the whole model, not just the support.

What am I overlooking? Why does Cura say 'will be printed with Extruder 1' and the result is 'Extruder 2'.

After 8 prints, of which some were overnight, I've already lost quite a lot of PVA....

Edited November 1, 2017 by Guest

[Grasmier 0]

Update 1: I discovered that the shell/wall thickness of the model I import into Cura is 0.3 mm. And when I select Layer-view in Cura, the walls do not show up at all. Is 0.3 mm too little for Cura to detect? Or should I only import solid models in Cura?

Edited November 1, 2017 by Guest

[tomnagel 126]

Yes, layer view should exactly tell you what your printer will be printing.

It is probably best to use your CAD program to increase the wall thickness. If that is not an option, you can use the Cura option "horizontal expansion" to increase the wall thickness. Use layerview mode to see how it impacts your model.

I notice in your picture of the filaments that you have not installed the PLA as designed. You should use the filament guide on position 1. It prevents the filament from interfering with the other spool.

Edited November 1, 2017 by Guest

[Foulkn 0]

I am having the same problem.

Have you been able to solve this problem? Please post solution. 

 

Cura 3.1.0

Ubuntu 16.04

[kmanstudios 1,120]

27 minutes ago, Foulkn said:

I am having the same problem.

Have you been able to solve this problem? Please post solution. 

 

Cura 3.1.0

Ubuntu 16.04

I believe this is the solution that you were looking for:

On 11/1/2017 at 7:06 AM, Grasmier said:

Update 1: I discovered that the shell/wall thickness of the model I import into Cura is 0.3 mm. And when I select Layer-view in Cura, the walls do not show up at all. Is 0.3 mm too little for Cura to detect? Or should I only import solid models in Cura?

and:

On 11/1/2017 at 5:01 PM, tomnagel said:

Yes, layer view should exactly tell you what your printer will be printing.

It is probably best to use your CAD program to increase the wall thickness. If that is not an option, you can use the Cura option "horizontal expansion" to increase the wall thickness. Use layerview mode to see how it impacts your model.

I notice in your picture of the filaments that you have not installed the PLA as designed. You should use the filament guide on position 1. It prevents the filament from interfering with the other spool.

Most problems can be attended to in the model when it comes to goofy stuff like this. Use your x-ray view and layer view when you have finished slicing. You can isolate the materials and see where walls fail, but support is still trying to support them.

[kmanstudios 1,120]

On 11/1/2017 at 7:06 AM, Grasmier said:

Update 1: I discovered that the shell/wall thickness of the model I import into Cura is 0.3 mm. And when I select Layer-view in Cura, the walls do not show up at all. Is 0.3 mm too little for Cura to detect? Or should I only import solid models in Cura?

Tackling this as a separate response:

 

Yes, 0,3 is less than the line width, therefore it is not sampled. Thicker walls should be at the very least the same thickness of the nozzle and at better, twice the thickness. You do not need to bring in a "Fully solid model" because many models do need to have interiors. But the walls should follow that basic rule and be manifold themselves; i.e. solid themselves. Many models uploaded are just 2D sheets and just will not slice and create other weirdnesses.

 

See this thread for an example of that.

Edited January 29, 2018 by kmanstudios
Typelexia

[Foulkn 0]

Sorry I did not specify. 

My problem is with Cura reversing extruders.

[kmanstudios 1,120]

Just now, Foulkn said:

Sorry I did not specify. 

My problem is with Cura reversing extruders.

have you just tried to print a simple box to see if it does it?

[Foulkn 0]

OK, that did not really make sense. I tested with a one color test cube and work correctly. Reloaded the test bridge and now it is starting with the correct extruder. 

 

I just finished setting up Marlin with my Hictop for dual extruders and it actually started the test bridge correctly. I had to stop it because the new extruder motor was running backwards. I switched direction and re uploaded, after that it would no longer work. 

 

[kmanstudios 1,120]

That is a bit strange. It would seem that there is a curious communications error. Especially after what you described.

 

Just for kicks and giggles, try the process this time, but make sure the extruder is going in the right direction than before.

[gr5 2,172]

Let's get back on subject.  For the UM3 what could he have done to make one object print on one extruder and the other object print on the other extruder?  And how could he have seen this in layer view?

[kmanstudios 1,120]

He is using a 3rd party printer, the Hictop. That creates an issue I am not familiar with having only used the UM3 series.

 

But to answer your  questions:

1. When you select an object, you can go to the bottom of the left side strip and there are two icons with numbers that are circled. They match the extruder icons in the top right of the interface. You can select either 1 or 2 and it will assign the appropriate feeder that you want to use.
2. You can also see the material colors on the objects in solid view. But they highlight to a degree that if they are close in color, they are not easy to distinguish.
3. Selecting the layer view, you can choose to see things by material color so that you can tell what is printing by which extruder. Not much help if your choices are very similar in color, but you can see what is printing what with each extruder by way of color. It is the best way to make sure you are not making a bad selection. I almost did that one day by not paying attention to a couple of default settings. This would be the brim and support. I always use PVA for my supports as I mostly do 1 color printing. But, the brim and supports had been overlooked for some reason and it was all printing with the default extruders for Brim and support, extruder 1. You can also turn on or off different types of functtions, such as turning off the helpers or infill, or walls.

As far as I can fathom, this should work on any dual nozzle printer. But, in odd cases, there may be some weird cross talk or bug that does not like to play along. Outside of the UM3 series, I am making extreme guess work.

[gr5 2,172]

@foulkn - sorry - I read it too quickly.  The title of this topic mentions and the first post shows UM3 so that confused me.  Your problem is "not the same problem" and should have been a different post but whatever.

 

If you click on extruder1 and extruder2 in the top right in cura in layer view it makes the model darker/brighter.  Brighter shows which models are printed with which extruder.  Maybe you accidentally clicked on the button just above where you change between solid and layer views which assigns one of the models to one of the layers.  Maybe you should just start over and avoid those 2 buttons. 

 

I think it would be helpful if you posted some screen shots of what you are seeing in solid view when you click on each part and when you click on "layer 1" and "layer 2" in the top right.  And note which button is highlighted above the layer view button.

 

I also use cura in Ubuntu.  Yah Ubuntu!  But sometimes the (assign part to extruder) icons go all fuzzy and I can't read them and I can imagine you clicked on one by accident.

[Foulkn 0]

I chose to join because even though he was using the UM3 the problem he has was exactly the problem I had with using the second extruder even though I had all settings indicating to use the first.

I checked the G-Code output and it was wrong so problem was with Cura not the UM3. 

Once I printed the single color print it picked the correct extruder. Since then even 2 color has worked correctly. 

Now I get to learn the intricacies of dual color printing. 

Thanks for all the suggestions.

 

Ed. 

[kmanstudios 1,120]

Just now, Foulkn said:

I chose to join because even though he was using the UM3 the problem he has was exactly the problem I had with using the second extruder even though I had all settings indicating to use the first.

I checked the G-Code output and it was wrong so problem was with Cura not the UM3. 

Once I printed the single color print it picked the correct extruder. Since then even 2 color has worked correctly. 

Now I get to learn the intricacies of dual color printing. 

Thanks for all the suggestions.

 

Ed. 

Still damned weird that would happen though. But, I am glad you got it figured out.

 

Just out of curiosity, are you doing multicolor prints or using the second core for support?

[Foulkn 0]

Support.