Feed Failures with PETG

[Jules]

First a warning, I am an EE and a rank amateur at 3-D printing. I read about PETG and really wanted to use it and I made some test prints and it came out great, much better than expected. I love the combination of tuffness and flexibility, plus the semi transparent material has a jewel look to it.

So I go to print the real parts and I get the feed problem talked about in this topic. I keep trying different FFF settings (slower printing , hotter/cooler, more or less feed multiplier, etc) and nothing worked (different results).

I'm such a novice that I didn't know there was a extruder screw adjustment until I found and read this thread. I didn't see anywhere in the MakerGear directions about adjusting this screw. The eSun is on the small side (typically 1.65 to 1.72mm from my measurements and what I have read). I noticed the screw was loose (which I guess is right for PLA) so I cranked it all the way down and it feed a little bit and stopped with a clicking sound (OK that was too much). So I used my thumnail as a feeler gauge (later measured to be about 0.4mm thick) to give a small gap. On retracting the material after adjustment, I notice that I had a nice gear indentations in the filament such as showing in the article at: http://softsolder.com/2015/03/13/makerg ... entations/

I'm about 2 hours into a 12 hour print and so far so good. You mileage may vary.

Congrats, on accidentally discovering the Filament Drive tension screw...we have a write-up on how to determine the correct tension here:

viewtopic.php?f=3&t=2694

The Beginner's Guide for the new machines will be posted this evening.....it's currently under review by the experts. (Watch the forum for new posts. )

[treat1]

As I warned, I am a newbie. Well I think I had too much tension and/or a combination of size issues with the ESUN filament. About 4 hours (approximately due to where it stopped) into printing I got an extruder jam. The there was a lump of filament after the roller so the filament could not extrude. I was able to take just the extruder apart and the roller out and push the filament through in the reverse direction.

So I am guessing there is too much tension so I backed off on the tension to try again.

Thanks Jules for the link, I wish I had found that first. One would think that the "quick start" guide for the printer would talk about this.

One comment, I like the "patterning"/bite that is show in the guide, but wonder if the pattern should be a little different based on the material. The PETG for example a bit softer than say PLA and therefore might need a bit more tension/force. Once again, I am new at this so this could be completely off.

[Jules]

Nope, you want exactly the same pattern bite in any filament you print....only 10-15%. That means adjusting the tension on the screw when you switch to a different type of filament, but too much of a "bite" will cause jamming no matter what filament is in there. (And it's worse for the softer filaments like PETG.)

[Jules]

Oops, I'm so asleep at the wheel these days.....treat, if you're new and this is your first time printing PETG and you haven't slowed down the printing speed for that filament (and upped the temperatures) over PLA you're going to have a lot of jamming. Be sure to check the Filaments section of the forum for info on printing PETG, and read the guide that pertains to your machine tonight. You have a new Rev.E machine, and a lot of the tutorials and procedures for the previous version do not apply to you. (The Filament Drive one does though.)

[treat1]

Jade, thanks,

I knew about the temperature and print speed and downloaded an FFF from another thread on the PETG subject. There is all kinds of information about what print settings to use, BUT I did not find out anything about the extruder screw tension until I found this tread. It was a doh moment when I realized that it was adjustable. The "quick start" guide should really have a part that has a brief explanation of anything that a user may want to adjust and really something like the "how much bite" you linked to should be included (or at least a link to it). When you are starting out, it is good to know EVERYTHING that is adjustable so you can know that it might need adjusting.

[PcS]

If the filament doubled over itself. Then you are trying to print it to fast.

[Jules]

Jade, thanks,

I knew about the temperature and print speed and downloaded an FFF from another thread on the PETG subject. There is all kinds of information about what print settings to use, BUT I did not find out anything about the extruder screw tension until I found this tread. It was a doh moment when I realized that it was adjustable. The "quick start" guide should really have a part that has a brief explanation of anything that a user may want to adjust and really something like the "how much bite" you linked to should be included (or at least a link to it). When you are starting out, it is good to know EVERYTHING that is adjustable so you can know that it might need adjusting.

That kind of thing is in the Beginner's Guide here. (Which again, is not the one you need to use......yours will be posted tonight.) Ain't it great being on the cutting edge?

[treat1]

Thanks for all the help and input . . . but I am hoping my problem is the ESUN filament.

I have tried doing the calibration of the feed by making the 10% to 15% bites into the filament. I have back off and gone and littel tighter and NOTHING works. It will feed for one to as many as 3 hours and then it jams.

The ESUN filament I have is definitely undersized and has the "rough" finish.

I see you and others say you get the circular ware mark when the tension is too much, but I get this when there is little or no tension (the tension screw is loose and less bite into the filament). I have had the filament stop with the half circle cut out of the filament, I have had the filament blob up and jam after the drive wheel, it has balled up and jam before the drive wheel.

I'm really hoping it has something to do with variations/defects in the filament as I like the mechanical properties of PETG. I have two different brands on order (Hatchbox and 3D Solutech) to try and see (they are due in Friday and Saturday). I also gave the ESUN roll of PETG to someone with a ROBO printer so see if a different extruder makes a difference. I will report back my results.

[PcS]

Print at 1800 mm and at 255 or 260 .I run my filament tension very tight. I would rather see the filament doubled over itself than have the half circle cut out of it. In either case when you see either of those issues it is...at least in my experience caused by trying to print to fast. The v4 never clogs for me. Once in two years I think.Slow and steady wins the race. I have ran a lot of 30 plus hour petg prints with great success as long as I did not run too fast.

[wmgeorge]

I usually print with PETG and I might have discovered something after I printed a new extruder end out of PETG. I was having problems feeding and someone here suggested drilling the hole in the nozzle after the drive gear to a diameter of 2 mm. I did so and it worked great after that. Since we are using 1.75 filament, the 2 mm hole makes sense. As long as the filament feeds into the hot end, that's all you need. Two jams since August 2015.