Problems with PLA and Breakaway

[Emerald 1]

Hi,

 

we've got a brand new Ultimaker S5 at work and I've been experimenting with it so far. I've used tough PLA, generic PLA, PVA and Breakaway.
We can't use PVA because of regulations of our towns water supplier. Therefore I started to work with Breakaway more and run into problems and I can't figure out what's going wrong.

 

It seems to be either oozing or under extrusion and its never both at the same time.

 

When the filament is oozing it results in a wrong distance of the nozzle to the bed during auto leveling, because Breakaway forms a blob which cools down and Ultimaker levels against the blob rather than the bed.

 

When the filament is not oozing I'm dealing with under extrusion to the point that almost the entire first layer is only printed in small dots.

Before I start a print I check if the material is able to flow out of the nozzle. After that I know I will be dealing with oozing.

My setup routine is me standing beside the printer and wiping all oozing material away, hoping after calibrating the first nozzle no material will be stuck under the second one, because there is no time for me in between for brushing that blob away. 

 

I experimented with ooze shield and prime tower to deal with oozing during the print. The prime tower works best atm but it is far from perfect. There are some bits that get stuck in the main material.

 

To deal with under extrusion I placed a helper disk and print it as support.

 

I hope someone can help me figure out the problems as I don't know the normal behavior of Breakaway. Please see attached pictures of the problems i ran into. (Order of appearance: Breakaway wasn't printed, lost blob on print, Nozzle was too far away, under extrusion, under extrusion on first layer)

 

Thanks

PS I see that this is a recurring topic so this is somewhat similar to my problem.

 

 

Edited September 25, 2019 by Emerald

[geert_2 557]

I can't answer your questions about breakaway, as I never used it.

 

But concerning PVA-regulations: if you can not legally dissolve it and flush that waste-water down the drain, then maybe you could legally pour it over old newspapers, let dry, and throw away these newspapers? Then it does not pollute rivers. Very often old paper is recycled separately, this is the preferred option. But in our city it is also allowed to throw it in the regular "rest-section" of trash, because it makes it easier to burn that rest-section. See your local regulations. Or make papier-maché from it (=mix of old paper, water and wood glue until it is a clay-like paste), and use that to mould artwork? Or let the kids make art and toys with it? (But check the skin-safety first and let them wear gloves.)

 

This might be a temporary and legal workaround until you get the other issues solved?

 

[Emerald 1]

Thanks for your input, Geert.

 

Since the printer is at my workplace, I can't make a mess with drying the waste water on newspapers. My colleagues wouldn't approve either.

 

I get the printer to work but it is such a hassle atm. Some times I need to cancel the print multiple times until I get the perfect first layer. I even save the print on USB to avoid walking between my desk and the printer. I simply want to start a print without watching the entire setup routine. 

Maybe it is a bad batch of the Breakaway material. I don't know if it shows tendencies of oozing normally. 

 

I wanted to add, that I print with the recommended settings for generic PLA and Breakaway.

[Emerald 1]

Hi again,

 

I wanted to share some pictures of my most recent print.

 

First I checked the material flow manually and started a print, which I aborted, because the nozzle was too far away. So I tried again, this time with severe under extrusion on the first helper disk. Thankfully I placed a second one and the print came out ok afterwards.

Additionally I tried to capture the cold blob, that causes my leveling problems. This was snapped after the leveling process and during the heating of the first extruder. (Tweezers for focus.)

 

 

[johnse 31]

I have the UM3, so slightly different, but I have a bit of a different experience.

 

like you, my Breakaway oozes as the nozzles are heated. I always have Breakaway in nozzle 2 when using it, and it measures nozzle 2 first during the nozzle height comparison test. This always puts a tiny amount of Breakaway in the spot where that test is done, but it doesn’t seem to cause problems. The key here is that the nozzles and bed are heated at this point.

 

After that it does the 3-point bed leveling measurement. On the S5, it would be the mesh measurement, I presume.

 

The only time I tend to have a large ooze blob on the head is if I stop the feeder too soon when loading.

 

When loading, I’ve noticed that a thin ooze will drain from the nozzle before the filament is fully loaded. I always wait until I see a steady flow. The Breakaway has a bit elasticity that makes the thread to be a bit thicker than the nozzle width. I can actually see the thread pulled up a bit when it retracts at the end of loading.

 

Between being sure it’s fully loaded and using a prime blob, I’ve never had underextrusion issues with it.

 

Good luck.

[Emerald 1]

Thank you, johnse, for your reply.

I'd like to comment my experiences:

 

13 hours ago, johnse said:

like you, my Breakaway oozes as the nozzles are heated. I always have Breakaway in nozzle 2 when using it, and it measures nozzle 2 first during the nozzle height comparison test. This always puts a tiny amount of Breakaway in the spot where that test is done, but it doesn’t seem to cause problems. The key here is that the nozzles and bed are heated at this point.

 

I can verify this behavior. The second nozzle oozes a little bit.

 

13 hours ago, johnse said:

After that it does the 3-point bed leveling measurement. On the S5, it would be the mesh measurement, I presume

 

The S5 levels with the first nozzle roughly 50 times. In between the second nozzle cools down to idle temperature (100°C).

After that the second nozzle is again leveled against three points. If there is a blob, this will cause the nozzle be too far away during the print.

 

There is no chance for me in between to bush this blob away and I can't pause during calibration.

 

13 hours ago, johnse said:

The only time I tend to have a large ooze blob on the head is if I stop the feeder too soon when loading.

 

I cant't verify this, as I'm certain the material is loaded correctly.

 

13 hours ago, johnse said:

Between being sure it’s fully loaded and using a prime blob, I’ve never had underextrusion issues with it.

 

I tried to tackle this with my helper disks. I'll try prime blob next.

 

 

It seems as I always have to abort once to produce some sort of small blockage on the extruder only to purge it again with prime blob or helper disks. This can't be right, can it?

 

Over all this printer is awesome and produces nearly perfect prints. It just has some hiccups during starting sequence. Is there a way to pause during set up for me to intervene? 

[jones007 1]

I have both a U3 and several S5s, and I can report pretty much the same experience. The U3 is actually easier to work around. It never heats nozzle 2 enough for the breakaway material to ooze during active leveling. I just need to remember to clean the tip well before leveling starts. On the S5, I have not found a fix other than babysitting the printer - to include 2 or 3 aborts and restarts for each job that includes breakaway material.

 

I too work at a facility that does not allow me to dissolve PVA into water without treating the water as hazmat afterwords. I generally like the performance of the breakaway support material - with the exception of the startup procedure. It seems to stick a little bit too much to some materials (CPE, for example), but generally works well.

 

Is it possible that perhaps retracting it a bit more at the end of a print, and feeding a bit more into a prime blob would help out here?

[Emerald 1]

Thank you for your reply, jones.

 

At least I'm not alone with the problem of oozing breakaway. 

 

I changed following settings 

• Enable Retraction to true (checkbox ticked)
• Limit Support Retractions to False (checkbox not ticked)

I left the retraction distance unchanged, because I didn't figure out which nozzle would be affected by this. The amount of the print blob is fine, perhaps a little too much because it sometimes sticks to the print core housing and strings all over the place. However it can be removed easily and is not an issue at all.

 

It seems there is no other way than observing the start up and first layers and abort the print sometimes. Other than that, I'm really happy with this printer.

 

Are there any other settings that can be tweaked?

[johnse 31]

Some things that might help:

* Sometimes, in addition to the prime blob, it will print a second skirt in Breakaway. This nicely deals with the stretched line from the blob to the print. I really wish I knew what setting caused this second skirt...I’d enable it all the time.

 

* in lieu of the above, try positioning your model—or a model—such that a first layer area of support is closest to the prime blob. This can minimize the effect of that blob string getting embedded in actual part.

 

* failing thin towers, often outside the model caused by internal  support too close to the edge, can cause lots of debris. Once a piece breaks, the rest of the layers for that section print on air and cause lots of curly chaff to be blown around. Try decreasing Support Horizontal Expansion ( downside is this may make intentional towers less stable) or place support blockers sized to eliminate these unwanted expansions.

 

An example of the latter can be seen in this post to which no-one responded.

 

 

[jones007 1]

@Emerald: thanks for the tips. I'll try those. I haven't had too much trouble with the prime blob tagging along, but I've made sure to apply glue to the entire print bed, including where the prime blobs go.

 

@Johnse: I try hard to avoid skinny support towers, as they always fail, but I have yet to get the support-removal option to work as intended in Cura. I guess I need to look for some YouTube video to demonstrate use, as intuition is failing me here. I have run into other support issues that are super annoying. I have been printing a lot of large shell structures, where I need support underneath to support the top part of the shell. Unfortunately, I have some small bolt holes adjacent to the hollow parts, and Cura seems to like to add support for some radius around where it is really needed - to include on the opposite side of a vertical wall. This includes stuffing microscopic, useless strands of support in vertically oriented bolt holes. I have not figured out a way to prevent this, and of course, they always break and end up as junk stuck in my part.

 

For the most part I love the S5s. They print quite accurately, and pretty large parts. However, on both of them I have had to disable the filament detection. On the first S5 it worked for a month or so before the detector failed. On the second it never worked. In the end, it's very nearly a useless feature, for me anyway. The idea is that it would pause a part if you ran out of material and let you swap in a new spool. In principle this works, but if you let the part cool before swapping in the new spool, I've found the layer adhesion to be rather poor. Most of my jobs are multi-day, and if the spool goes out in the middle of the night, the part is really wrecked anyway, so no point in restarting. I should qualify this - this has been my experience for parts that are intended to be structurally functional. If you're printing something that just sits on a shelf, I think this would be a useful feature. The auto spool swapping from the new S5 Pro Bundle might resolve this, if they could get the filament detection system to be more reliable.

[johnse 31]

For support blockers:

1. select the part to which blocker should apply
2. select the blocker item on the left side
3. click on selected part somewhere close to where you want blocker. This inserts a grey transparent cube.
4. Select the cube
5. Switch to sizing. I find it useful to uncheck the keep proportional. Use handles to stretch block to contain areas you don’t want support. For example, the entire height of a thin column.
6. position (and I assume rotation-though I’ve not tried that) should work similarly.

The spreading of support through walls is caused by “Support Horizontal Expansion” defaults to 2mm.

 

i don’t have an S5, but I read on here that at least in some cases where the sensors didn’t work it was because the user placed filament reels in a different location, like a drybox or a reel holder to the side. The sensors are apparently tuned to expect filament to be entering the feeder from the central spool holder. Some found by crossing side-mounted filaments, so one from the right side entered the left feeder and vise versa made it work better.

[Emerald 1]

Hi again,

 

@ johnse: I noticed something weird during yesterdays print, wich took 20h to print and turned out wonderful btw.

I changed the extruder, which prints the skirt, to the second extruder which prints Breakaway support. I wanted to see immediately if the nozzle is too far away because the first layer often takes at least 30 min to print.

 

Oddly the S5 did not print a prime blob with Breakaway and starts right away with the skirt and first layer of support. After that it printed a blob with the main material and a additional skirt.

I think that this is not a setting in cura and coincidentally found out. Perhaps it is a feature? 

I haven't experimented with support blockers yet, but thanks for your detailed explanation.

 

@ jones007:  Maybe you can stop cura from filling small holes with support with the option Minimum Support Area? 

 

My colleagues and I are looking forward for the first insights from users with the new pro bundle and we consider buying one, too. At the time the filament is stored inside a box behind the printer and so far the sensor never failed. 

 

 

Edited October 9, 2019 by Emerald

[johnse 31]

Previous discussion of flow sensor issues. One user fixed by moving spools:

And @CarloK from Ultimaker replied with some explanation:

 

 

[Job_van_gennip 23]

Going for a very long shot, but what print core are you using for the breakaway?

[Emerald 1]

I'm using a AA 0.4 print core for Breakaway.

[jones007 1]

I'm using AA0.4 as well. Pretty much all my parts use 0.25mm for the build material, but it won't allow 0.25 for the breakaway. I'm building model aircraft parts that are extremely hollow, so 0.48mm walls and very low percentage fills. It's pretty amazing what you can get away with if you really push it.

 

@Emerald: Thanks for the tip - the Minimum Support Area took care of that issue.