Hoping for a little print failure guidance...
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Again thanks for all of the information and suggestions.
I've changed the first layer to .02mm and I slowed down the print from 60mm to 30mm. I keep pushing the nozzle down .05 while test printing, I think its getting close.. thoughts? The rings are built from the center outwards, so the nozzle is getting closer the further out from the center.
VB,
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@vbtalent2
The outer rings are looking much better. Measure them with a micrometer so there is no guesswork going on. Be careful to avoid any bumps so you don't get a false reading.If you set 0.2mm as your first layer in the slicer then your printer should be putting down a 0.2mm first layer. That is the ideal situation you are aiming for.
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I think you've got this part nailed. Now be sure that your zoffset in config.g matches your outer ring and move on to the next challenge.
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I really appreciate the insight and help...! you guys are great...
I'm assuming that this should check the box on the Extruder feeds and amount of material as well as Nozzle distance to the build plate, correct?
I'll follow up in another thread about the mechanics to keep things clean and separated.
If it were you troubleshooting the next where would you start?
VB,
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@vbtalent2 said in Hoping for a little print failure guidance...:
I'm assuming that this should check the box on the Extruder feeds and amount of material as well as Nozzle distance to the build plate, correct?
I'll follow up in another thread about the mechanics to keep things clean and separated.
If it were you troubleshooting the next where would you start?
Wondering if anyone had any input to my last few questions in my last post???
Thanks.
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Next steps... The big categories (I think) are:
Basic accuracy - if you print a cube, say 25mm on a side, and measure it with calipers, is it the right size? Do the corners look sharp? Are there bumps or wiggles? Does things change if the printing speed is increased? Is the top surface pretty flat, or does it have lumps and ridges?
Ringing - (seen most often at higher speeds). If you have stretch in your belts, or something can wiggle, you can get defects in your prints. The Duet board can compensate for some of these. You'll need to get an accelerometer chip and run some tests.
Adapting for shrinkage - When your parts cool, they'll shrink a bit. Print something long that you can measure after printing with calipers. Once you find the error (as a percentage), you can add compensation for that in your filament files.
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I'm still having issues getting consistent prints and a little lost on where to start.. I thought I was getting close after getting the nozzle dialed in but, no...
So I recorded a few short videos so people could see what was going on..
In this 1st video, there's no material coming out when the print starts and when it does it looks like a blob and doesn't seem to stick?
this second video just seems to compound on the problems, each successive line print creates another blob at the starting point and gaps can be seen in the "finished" section, it's just junk.
The third video, is just showing the progression and is a bit clearer where you can see the mass of material where each line starts as well as the gaps.
I also snapped a few pics of the print, hoping to get some clearer images.
Any suggestions would be helpful...
VB,
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To me, this looks like the nozzle is too far from the bed. I say this because the individual filament lines look rounded on their tops. If they are rounded on their tops, they are probably also rounded on the side that is touching your glass plate. That can lead to bit and pieces coming off the build plate to make blobs. On my printer, I try to make the top surface of the first layer flat and smooth. The part of the nozzle where the plastic comes out is most likely flat next to the hole. I like to think of that little flat space as an iron that is flattening out the filament on top and providing some pressure to push it against the build plate.
This is where baby stepping should be used. you start the print as you have it, then use baby steps to move the nozzle closer while observing whether the result on the build plate is looking better (in this case smoother). If the nozzle gets too close, then the end of the nozzle will be "plowing" through the plastic already put down and you'll get rough ridges, not the smooth ones you see in your pictures. Then baby step away from the plate until it looks better. .
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@mikeabuilder thanks for the reply... I understand the rounded tops, makes total sense.
How will I be able to tell if its over/under extruding?
Any thoughts on the blobs when its moving to the next line to print?
VB,
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@vbtalent2 The gaps between adjacent seams look frightening. Maybe you can get rid of them following @mikeabuilder’s advice - but I’m puzzled by the fact that these gaps just begin to appear after about 10 perfectly looking rounds. From your videos, I get no clue: the nozzle deposits the first layer pretty well.
I can imagine two possible suspects:
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Mechanical issues. I've seen inappropriately adjusted V rollers to generate these gaps. However, as the first few rounds look perfect, probability of this to be the cause is low.
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Under extrusion due to some clogging which develops over time. It is often caused by heat creep, i.e. the temperature of the heater block gradually overcomes the heatbreak up into the cold end (of your hotend). In most cases, this indicates insufficient cooling by the tool fan or a blocked air flow. Can you provide an image of your print head?
The blobs should be a minor problem - they didn’t appear with the gray filament you used before, so I think you you just have to fine-tune nozzle temperature and maybe pressure advance for the black filament (to begin with, I would not enable PA at this stage).
As a final note, I'd like to add that you got to manage adjustment of the nozzle height very well. It's a long time since I saw such a perfect first layer seam as demonstrated in your videos. On glass, this is a rare event. Congratulations.
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