Okay, I stand corrected. Like Jim, I have never had any moisture issues with PETg in spite of keeping it out of the dry box and in the open, but yes, I do have central heating/AC, and the humidity in my basement stays pretty low throughout the year. For that matter, I've never had issues with any filament that could be pinned down to moisture issues with any degree of confidence. Still, I use the dry boxes for PLA and especially for hydrophilic filaments like PVA, and it keeps the humidity at around 10-12%.
The one time I got really poor results from my (black, opaque) PETg was when I confused my spools and thought I was using my black PLA (since I still have a roll of the MakerGear PLA before they started using the filament that has a matte finish, so it looks exactly like the black PETg). The remarkable thing is that it actually printed at 215 degrees. Not well, but it printed.
eSun PETg transparent variability
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bignordique
- Posts: 32
- Joined: Wed Jun 10, 2015 6:44 pm
Re: eSun PETg transparent variability
For the benefit of anybody else out there with similar problems...
I think I've got three problems.
1. The nozzle had a considerable layer of charred plastic built up on it. The worst of it was on the difficult to observe backside. A good scrapping seems to have eliminated the charred chunks in prints problem.
2. I'm attempting to build a relatively large quantity of these objects. One of the differences between the two prints shown in the picture is the "good" object was printed one up and the "bad" object was printed four up. This causes the printer to discontinue extruding, skip to the next object and continue extruding. I've learned that starting/stopping extrusion is not such a good thing. This was leading to whitish color and blobs. These blobs probably contributed to problem 1 above.
3. Randomly distributed through the print are these fairly small ticks... a bit like what you see with a layer change. The "good" object has none of these. Following the nozzle scrape and switching back to one up, they are now present in the prints. I don't know where they are coming from. Possibly the filament? The good news is they are small enough not to matter, but I would prefer them gone.
The remaining real issue is production throughput. I really would like to print 4 up. Don't have a solution to this problem.
I think I've got three problems.
1. The nozzle had a considerable layer of charred plastic built up on it. The worst of it was on the difficult to observe backside. A good scrapping seems to have eliminated the charred chunks in prints problem.
2. I'm attempting to build a relatively large quantity of these objects. One of the differences between the two prints shown in the picture is the "good" object was printed one up and the "bad" object was printed four up. This causes the printer to discontinue extruding, skip to the next object and continue extruding. I've learned that starting/stopping extrusion is not such a good thing. This was leading to whitish color and blobs. These blobs probably contributed to problem 1 above.
3. Randomly distributed through the print are these fairly small ticks... a bit like what you see with a layer change. The "good" object has none of these. Following the nozzle scrape and switching back to one up, they are now present in the prints. I don't know where they are coming from. Possibly the filament? The good news is they are small enough not to matter, but I would prefer them gone.
The remaining real issue is production throughput. I really would like to print 4 up. Don't have a solution to this problem.
Re: eSun PETg transparent variability
The reason the 4up is whiter is all because of heat. The 1up print is hotter because it has less layer cooling time. You can increase your temp while printing a 4up batch. I have printed esun petg as high as 270. It will also be a little clearer if you increase your layer height. The ticks are what oozes out during the travel move. Try retracting a little more. Also if your on s3d then add a small amt of wipe, coast and as a last resort a little neg restart distance. Its all about tuning those settings o the first page of an s3d process. You can also choose to start each layer at the corner if a print which will collect all thise ticks in a row.
Re: eSun PETg transparent variability
If it fits into your workflow/needs, you can also try XTC-3D, it does improve transparency of PETG somewhat: viewtopic.php?f=3&t=1992
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bignordique
- Posts: 32
- Joined: Wed Jun 10, 2015 6:44 pm
Re: eSun PETg transparent variability
Thing were running pretty smoothly... then last night I again got some charred plastic in a print.
Sure enough the nozzle had a pretty fair coating of plastic char, again mostly on the hard to see backside.
Fixed the problem by removing the extruder and scrapping off the char.
Of course, removing the extruder is somewhat time consuming and I'd like to avoid that.
As an interim solution, I'm going to start inspecting the nozzle after each print and hopefully clean up the nozzle without removing the extruder.
But it seems the fundamental cause of the char is blobs. These tend to form in the "pre-game warmup". Usually, once it gets to the first layer the blobs have been wiped off. But not before coating the exterior of the nozzle with some soon to be charred plastic.
What I'd really like to do is figure out how to avoid the blobs altogether. I'm using slic3r. Anybody have any good ideas for blob control?
bignordique
Sure enough the nozzle had a pretty fair coating of plastic char, again mostly on the hard to see backside.
Fixed the problem by removing the extruder and scrapping off the char.
Of course, removing the extruder is somewhat time consuming and I'd like to avoid that.
As an interim solution, I'm going to start inspecting the nozzle after each print and hopefully clean up the nozzle without removing the extruder.
But it seems the fundamental cause of the char is blobs. These tend to form in the "pre-game warmup". Usually, once it gets to the first layer the blobs have been wiped off. But not before coating the exterior of the nozzle with some soon to be charred plastic.
What I'd really like to do is figure out how to avoid the blobs altogether. I'm using slic3r. Anybody have any good ideas for blob control?
bignordique
Re: eSun PETg transparent variability
What is your startup sequence? The one most of us are using homes, heats up bed and extruder, then moves the extruder off the right side of the bed and extrudes ~20mm to prime before coming back across the bed slowly to cut off the strand. Usually this results in no filament on the nozzle itself, unless it curled around, and you can always take the opportunity to fix any curls with tweezers before it finishes.
Re: eSun PETg transparent variability
Petg collects on the nozzle from overextrusion. Petg cannot be over extruded in the slightest. Actually it prints best when you get the rxtrusion exacly correct the back off the multiplier 1 point. Also the biggect pla e this happens is on the first layer and the bed gap being too tight. Vlean the nozzle before each print. Goto home depot, tool section where the welding stuff is. They have small stainless wire brushes for cleaning welding tips. Just give a quick brush before each print.