Black Filament Issues.
Well the saga of the new 3D printer just keeps on rolling along, first and foremost is it does print, there are jerks, grinds and levelling issues. But hey what in life is perfect, so time for some diagnostics (diagnosing) and then its on to the treatment. The black PLA I have been having problems with had compounded injuries as well as the difficult properties of the filament itself. Over the past week the black PLA print failures began to rise at a steady and consistent pace. From a very small lift on the front right edge of the prints, to a slow acceleration to not sticking, lines not connecting in the end. The obvious fact that it had to either be bad PLA that is inconsistent or it was a temperature problem were screaming out from the outset.
The first prints to show a loss of adhesion to the glass plate was the large white and gold print that was the last of the first three test prints I did.
It was only a slight rise and I thought nothing more about it as it was mostly a successful print. I set about building the battery pack and it was a couple of days before I got back to the print test. So it was time to test the black PLA. The first set of prints were not good and not bad, what would start of bad would end up good, and what would start of good would end up bad or good. This is where the idea of inconsistency came from and I just thought it might be the grade of the PLA.
After the levelling nut cap print it was looking like it had to be the quality of the PLA and I had about convinced myself of it by this time.Then this one started of great and the infill was even, with only little breaks in the lines no real big holes or gaps showing. The bad to good swing got me thinking more that it was inconsistency in the PLA at this point.
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I was frustrated and began scouring YouTube to get some answers, as well as looking in the ADIMLab groups search and files section to get a clue. Still no luck and the prints were getting progressively worse.You can see from the outer circle (above) I had to lean on the head to get traction going and that when I let go, a blob would be laid down from the backing up in the extruder. There were a few prints and failures from strings breaking down to not sticking and just leaving the print plate entirely.
So all the results were making it look like the PLA was just too inconsistent to be of any use. I then took one of the magnetic surfaces and decided to stick it to the glass to try to overcome the adhesion problems, I could always turn it glass side up again if needed. This still only had limited success as the first two tries still had to be held down with the putty knife, just like on some of the glass prints.
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Then during a coffee break I noticed how cold it was getting and then I found that the printer was right in the airflow current of a draught coming from my living room door and it was heading to my kitchen window vent. It was not enough to be noticeable to me as I felt nothing on my bare arms leaning over the table front end.This made it clear that the temperature drop over the previous four days may well have had something to do with the gradual deterioration in print quality. The first thing to do was to make a draught excluder for the door, as nothing will stop the flow from the front door to the living room door.
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This solution then needed a way to warm the airflow so that when it hits the print plate it will not cool the print head. When using the black it then proved better to have the extruder fan off as well and except for the first failure after the fix, to switch it back on for the lighter pigment colours.
As this image shows the gold running at the higher temperature after the air current fix was just a melted mush on the black surface.
Then it all just clicked with the convector on at medium, no fan on the black PLA and the draught excluder at work. It became clear I was still running too hot on the print for both the extruder and the print plate temperatures. This led to a print at 190 extruder and sixty for the print plate, with the fan of for the black and the gold still melted. Then I realised that the heat would now be secure with the convector and the air current being warmed up, that I could reduce the heat to a more normal level.
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The proof of the pudding is the last two prints where the black did not have to be started (leaned on the head) and except for a slight problem with the heat being too high for lighter pigments forcing a second change to the temperature, to the lower setting (above pics). With that and the ten or so days it took to get to the bottom of the problems and to realise it was not a single thing but a combination of things, the PLA problem is now resolved.
This now just leaves the ghosting and the judder that are the aggravation to the heating problems I had. They now require a bearing rail solution to get the printer into a stable 3D printing platform. I will design the bearing carriages to run on the existing gantry rails. The upright columns will have the carriage in the same fittings as the rail is fitted to the outside of the columns. The X arm will have a side mounted fitting, with a new head carriage designed to hold the extruder head. The Y rails will be an all new design as the ripples and the echo marks indicate the shake was aggravating the temperature problems that just got fixed.
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The mat on the glass has also raised the levelling to a ‘tight to the paper’ levelling program to get first time takes on the mat. This resolves the printing issues as now it actually prints. Now its all about the quality of the print and the finish that can be achieved.
This quick fix has a happier outcome as I have a large walk in wardrobe that will now house the 3D printer and the laser engraver that is coming next month. The area in the double door closet is seven feet by five by eight and a half feet. Just have to put a small thermostatic heater in and draught exclude the doors. This will have to wait till next month as my clothes are occupying the space, I will just stick to this living room arrangement for now until I need to put them in the other room where the engraver and the printer will have a shared atmospheric controlled environment.
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This is a little video edit of the process, it took since Friday to do all the editing reshoots, and re-editing. Learning what I used to do at ease again says a lot of damage has been done. It was compounded by all the updates since I used to use the programs. Updates I never had the time to get up to speed with so a lot of changes were slid under the door that made each of them a lot less than they used to be. I had to use Shotcut to get the final finish and then use Any video convert to reduce the fine HD media I made into something I could upload to the YouTube channel. Still, here is the first the others are in the next two articles that will be up in the next hour. So enjoy this take on the Black filament saga.