Gremlin in the Artist-D

Today has been a real nightmare. I have tried to print a unicorn for my great-nieces and got one printed and have tried 5 times today and every one failed. I started off by doing a small unicorn and using PVA. As the Z height increased the PVA seemed to get less and less to where it looked like a sponge and also felt like sponge. Since this is the first try at using PVA, I didn’t know if that was normal or not, but I didn’t think so. I was using extruder 1 as the PVA and extruder 2 as PLA or the main body of the print. I have had extruder 1 give some problems with some very sparse layers like there were layers missing. Really, like layers missing. The thing it would not repeat on the next print.
I tried the second print of the unicorn and the PVA broke loose from the raft at the tail. Another thing I noticed and noticed before was when the raft is printed extruder 2, extruder 1 does not drop to the raft but stays about 5-6 mm above, enough that the filament does not extrude to touch the raft. I learned to back off on the Z height by turning the motor down by hand to touch. Enough said there! At this point, I checked the level of the bed and found it was level. No adjustments were needed! I did some re-slicing and then noticed that extruder 1 when printing the raft was very under extruding - very to the point that it at first try would not extrude at all. At this point I took the extruder apart, could not find anything wrong and put it back together. I re-leveled the bed. Found that any time I change nozzles or disassemble the extruder that is necessary. Again it under-extruded. Out of a stretch, I checked the machine settings extruder1 and extruder 2. Some how the values of the extruder steps disappeared. Still trying to figure that out - The Gremlin got it. I re entered them and things seemed to improve. Then after the raft printed -3 times - the filament started to brake. Both of them! Explain that! I finally gave up for the night and will take a real hard look tomorrow. If any one can give me a suggestion as to what is happening, PLEASE chime in!

I’ve never printed with PVA so I know noting about it. If the filament is breaking I would say that it might have moisture in it. Do you have a filament dryer? If so I’d put it in there for 6-8 hours. My next suggestion would be to try printing the unicorns with PLA and see if you have the same issues. The printer loosing it’s settings, mine has done that too and for the life of me I don’t know why.

Sometimes a new day just magically fixes things too. Can’t explain that either.

First, I guess I, in my story, did not make things clear. The PVA filament did not break, it just under-extruded very bad on a progressive manner. It seemed to flow great at first and as layer numbers increased, it seemed to get worse. This, after finding my work around for only having one memory storage for two extruders steps to store, was missing. This also, seems to hamper knowing how the firmware reacts to duel extrusion and reading the machine settings in Cura. The filament that was breaking was PLA and both had been in vacuum bags with silica gel. One I had vacuum sealed the other from the factory. Looking back, as I have been studding things, I had the spools feeding from the outside and not from the inside I normally do. Just a trouble shooting thought with no proof of fault.

It would be great if the new day chased the Gremlin away. But, I think I will have to get a witch doctor to do his charm. LOL

As you said, I have never printed with PVA either, so all the problems with it just appeared at first to be normal. The other problems I was experiencing made these peculiarity’s seem to not be normal.

Now I hope I have not confused things more for anyone willing to help!

Just to clarify things for me, my understanding is that you’re printing a unicorn in PLA, using PVA for supports. The PVA is being fed through extruder 1, the PLA through extruder 2. The PVA is underextruding more and more as the height of the model increases. The PLA has started breaking, but you’ve also switched the way the spools are mounted, so the filament is feeding into the extruders from the opposite side of the spools from before.

Do I have that correct?

The first part, for the successful print was done with PVA on extruder 1 and PLA on extruder 2. After several failures, I decided to remove the PVA because of its cost until I found out what was going on, I switched it out for PLA for the support. At this time I also changed which extruder was doing the raft to extruder 1. This is where the filament started breaking or pulling out of the extruders. I think that is the better answer. And yes when I placed the filament on the spool holder, I did have the feed from the outside instead of my normal inside. That was an over look and when I notice the switch I choose not to interfere with the spools, especially since the first print was the same way.

OK, that’s new information. I did not get that you aren’t using PVA anymore.

My suggestion, for the moment, is to try printing only from 1 extruder for everything. See if you can get a good print. If you do, try again using the other extruder.

I hadn’t given any thought about doing anything today but that is a thought. I haven’t planned to do any printing today, instead ease my brain a little to be able to focus better tomarow, but that being something I hadn’t thought about doing. I will do it today.

On a lighter note, I had both front and back doors open where I had company and had cooked and the house was worm. I had an uninvited guest. I was taking my plate back into the kitchen and at the cats food bowl was a racoon. I eased out and told my guests about the racoon and they scurried so fast to see it that it was scared by them and it ran out the back door. Later it came back in and scared one of them, so the back door was closed. Later while we were watching a movie, my can came running in and turned around at the door with its fur stuck up. Shortly the racoon came around the glass door and she pitched a fit and it ran and did not come around again.

@Gramps What can I say!

I have straining my brain as to my filament problem. I believe along with having the filament feeding from the outside instead from the inside. This created a problem normally as being not, I was doing the prints at 50mm/s with a movement between points of 162mm/s caused a tug that caused the filament to pull lose from the extruder or break. I have not looked close to determine if it is breaking or pulling out of the extruder or both. I do not know why the movement is so high, but I believe I will set it to 60mm/s which is just a tad faster than laying filament down.

Does anyone think I am correct or maybe give you an idea to what the problem is. At this time I have not sat in the chair or turned the printer on. I am thinking about finding a stl of a print I have deemed a success and re-printing to see if works ok before going further.

Normally, a movement speed that high is not a problem, but it may be in your situation.I would try the lower speed as a test.

I am currently doing a duel print of a screw lid container and I have slowed it down to 65 for the travel speed . I am using normal filament and not glow in dark or PVA. I will take several hours, 5 to be exact, let you know how it went.

Good luck and keep us informed

Its a Good Day! I did the duel print of the container with screw on lid and used the settings that @Ender5r mentioned for this kind of print. I had been either enlarging the female or the reducing the male a percentage or two on size. This works better, and I did learn something! I also got two perfect prints I can be proud to give away. Lets just hope I can do as well on others. The travel speed had also been reduced to 65 from over 120. One more thing, The filament that I had used was from less than 40% full and had not been placed in vacuum or other means of controlling the humidity, where the ones I had trouble with one was vacuum sealed and one was a new spool just opened.

That’s 3D printing for you: 1 day you’re up, the next you’re down.

A bit late, but PVA is very hydroscopic, fwiw.


Yeah, I forgot about that. Of course, it is kind of a ‘duh’ when you consider that it dissolves in water. ?

@Lowteck Glad. your having a good 3D printing day, hope you have many more before the 3D gremlins visit you again.

I should have known that the PVA would absorb water out of the air even where the inside humidity was 40% or less. My bad!

Me too. I thought about it for a nanosecond and then did 1 of these [SIZE=26px]?‍♂️[/SIZE]

Well the Gremlin struck again over the weekend. I started a new print of the last print and before I got 1/4th of the initial layer laid down the filament on extruder 1 broke. Extruder 2 filament worked fine. This print is a two piece model. A jar with threads and a lid with threads. After 5 layers the jar part laid down two layers with out doing anything except the outer wall on the lid. Then it proceeded to lay a layer down on the lid. Of course it was a layer too high and it really made a mess. I let it finish laying 5 layers down on the lid and it did the walls on the jar. The lid looked great. This had to be a Cura failure. I am still using 4.11 because 4.13.1 will not display the picture of model on the printer screen for reference, which I like. The whole print looked great when finished.