Noodly deposits on back right corner of models

[Stenrik 0]

I've been having a consistent issue with my new Ultimaker 3. 

 

I'm using the Ultimaker brand of silver PLA, with its PVA as a support. 

 

However, my printer consistently leaves these deposits of PLA material, only on the back right corner of the model on the bed.  It seems like it's not retracting properly when the head changes direction. 

I am using the UM3 default settings for temperature and retraction and such.  What is going wrong?

[Smithy 1,144]

Have you enabled the Prime Tower in Cura?

If not, give it a try and enable it, but position the tower manually nearer to your object. Per default, it is located in the back right corner and you should put it as near as possible to your object which avoids the stringing.

[Stenrik 0]

Thanks for the suggestion!  I just printed a new model with a prime tower.  I placed it near the spot where I was getting all the deposits (back right) and as close as I could get to the model.

The issue does seem to be largely gone (although I didn't print the same model to compare 1-to-1 yet). 

Interestingly, the noodly deposits were evenly distributed around the tower, rather than clustered in the back right corner as I would have expected.  Curious why that is.

 

But the main question I have now: is there a way to disable Extruder 2's infill material in the tower, or reduce it? 

The tower consumes a lot of time and material (adding ~23% for my current model).  And that's with the minimum tower size I could set (which was 11mm minimum size/3mm cubed minimum volume size to avoid the minimum volume box turning orange).  The slicer is currently filling all the rest with PVA.  That seems like overkill, especially since my primary issue seems to be with Extruder 1 (the silver PLA).  I want to conserve as much PVA as I can, any tips for reducing waste in the tower?

[Smithy 1,144]

The purpose of the prime tower is to also to wipe your nozzle, that's the reason why you have the zits now on the prime tower. The location of the zits depends on the travel moves, so they can be everywhere, not always at the same place.

 

The drawback of the prime tower is, that you waste some material, that's right. It is also not the best idea to keep the tower as small as possible. If you print higher models, the chance that the tower will fall down is very high. So usually you define a bigger diameter for the tower to keep the risk as low as possible. 

 

Normally the tower has no infill, it is hollow. But maybe due to the small size and the setting "Prime tower minimum Volume" it looks like an infill. Because this setting says, extrude this minimum volume per layer, to purge enough material. 

 

You don't need always a prime tower if you print with dual cores. Some users don't use the prime tower, only when using dual colors and not with PVA. But it depends on the model, so in your initial case, it was important to use it.

[Stenrik 0]

Thank you for clarifying.  Still seems like an awful lot of material to purge just to wipe the nozzle. 

 

I still have a lot to learn in judging what types of models need what, it seems. 

[Smithy 1,144]

It is not only to wipe the nozzle, but it also purges the nozzle after standby that you have a good flow.