1 Topic by MLA

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Topic: Has anyone printed PETG on the Press?

I got a spool of PETG from eSun to try out on the Press, but no luck...

I have turned my speeds way down, which helps, but I think the extruder is the issue. If I print below 230 I get the "thump of death" and nothing will extrude. If I bump the temp up to 240, I can print for about 15 min before the extruder gets too hot and the filament starts to jam before the hot end, bringing back the thump of death.

Has anyone else tried this material with the press?

2 Reply by trayracing

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Re: Has anyone printed PETG on the Press?

Does your extruder fan blow or suck? Flipped to blow into the extruder seems to cool much better, and it matches the Press in the marketiing video. (Rant about poor SD support suppressed. Mostly.)

Tried Inland (Microcenter) clear PETG last night. Initial results: Prints great so far on small prints! (Tried it because my heat bed is too dead to print ABS. Waiting on SD support on that one too.) PETG flows fine at 230C, but needed to go 240C to get better interlayer bonding. The corners lose some detail at that temp, so slowing down with a lower temp would probably be better cleaner - haven't tried that yet. There was also a little oozing and a few minor strings at that 240C. I'll know more after I've worked with it some more.

3 Reply by MLA

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Re: Has anyone printed PETG on the Press?

My fan is flipped to blow into the extruder. Are you using the plastic cover? It seems like mine cools better with the cover off. Even with the flipped fan I think cooling is my main issue. The heat sink on this extruder seems to be too thick to dissipate the heat and the fan location could also be better. I think I may try adding a 2nd fan that mounts on the front of the extruder or relocate the existing fan to the front. I can get the PETG to print great at 240 for the first 15 or so min before I get the thump of death and at this point the top of the heat sink where the filament feeds into the extruder is hot to the touch. I don't think much heat should be making it that far up...

4 Reply by jagowilson

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Re: Has anyone printed PETG on the Press?

You are experiencing heat creep, which causes failure for PET because of its low TG temperature. Not a lot you can do with the stock hotend except put a fan around the heat sink of the hotend itself like e3d does. Oh did I mention an e3d will solve this problem? wink

5 Reply by MLA

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Re: Has anyone printed PETG on the Press?

I will definitely be looking into an e3d in the future if I can't fix the cooling issues with the stock extruder.

6 Reply by jagowilson (edited by jagowilson 2015-03-11 18:53:03)

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Re: Has anyone printed PETG on the Press?

Try a shroud with a 30-40mm fan around the hotend heat sink, if you have room. That would keep the heat sink at ambient and prevent the filament from becoming flexible. This is what e3d does and it is extremely effective.

7 Reply by trayracing

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Re: Has anyone printed PETG on the Press?

Yes, I'm using the plastic cover. Running at Vref 1.4V, so a little less heat from the stepper. Also forgot to mention the square of ceramic fiber insulation sitting on my heater block, but I haven't done measurements yet to claim its efficacy. And I haven't tried a long print (hr+) yet with PETG, so I could be on the verge of stalling for all I know.

The fan is also the wrong kind for the job - this sort isn't designed for the back pressure of blowing into the slots. I've thought about replacing it with a blower fan (4010s), with a little bleed air leaking between the fan body and motor to give a little motor cooling too. Haven't gone there yet - keeping it stock while it's under warranty. (Although given the support, not sure why.)

Also, our PETGs might be a bit different.

MLA wrote:

My fan is flipped to blow into the extruder. Are you using the plastic cover? It seems like mine cools better with the cover off. Even with the flipped fan I think cooling is my main issue. The heat sink on this extruder seems to be too thick to dissipate the heat and the fan location could also be better. I think I may try adding a 2nd fan that mounts on the front of the extruder or relocate the existing fan to the front. I can get the PETG to print great at 240 for the first 15 or so min before I get the thump of death and at this point the top of the heat sink where the filament feeds into the extruder is hot to the touch. I don't think much heat should be making it that far up...

8 Reply by MLA

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Re: Has anyone printed PETG on the Press?

I picked up a 40mm fan and started working on a shroud design. We'll see how it goes, space is very limited on this thing!

9 Reply by trayracing

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Re: Has anyone printed PETG on the Press?

trayracing wrote:

And I haven't tried a long print (hr+) yet with PETG, so I could be on the verge of stalling for all I know.

Yep. Dreaded thumping started at about an hour into the print. Sigh.

10 Reply by MLA

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Re: Has anyone printed PETG on the Press?

Well... I added a fan to blow on the heat sink and left the stock fan in place to pull the warm air out. It did help a lot with the cooling issue. I couldn't print abs over 235 without getting the thump of death. Now I have printed a few longer jobs at 250. However, the fan did nothing for printing petg. I can print for about 15 min before it goes to hell.

Here are a few pics of the fan. Anyone have any other suggestions? If anyone's interested I'll share the stl file.

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11 Reply by trayracing

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Re: Has anyone printed PETG on the Press?

OK, now that's weird. Today when I tried PETG again, it came out yellowed, like it'd been cooked. Considering print temp on the label is 250 and I was printing at 240, I shouldn't be printing too hot. The temp sensor is giving credible reports, but the print looked soupy in the last few layers before it jammed.

I'd blame it on the spool, but the change happened between prints, so it's unikely to have lined up so well with the print boundary. Dunno.

12 Reply by trayracing (edited by trayracing 2015-03-18 02:24:24)

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Re: Has anyone printed PETG on the Press?

Got a 2 hour print at 230C & slowed to 30mm/sec external perimeters for better bonding.
(Woot!)
Then it jammed starting the next print.
(Bummer.)

Don't know what the yellowing was about - it cleared up part way into the 2 hr print. Maybe some sort of contamination when I cleared the jam?

13 Reply by n2ri

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Re: Has anyone printed PETG on the Press?

I think the press has trouble printing with recommended filaments much less exotics

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs