1 Topic by poppinfresh (edited by poppinfresh 2016-01-27 03:07:35)

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Topic: Having a very hard time with PETG....

I've tried so many different things now I'm running out of options.

I'm using a MakerBot Replicator 1 DUal Clone from MonoPrice.
With PLA it is da bomb.  But so far not liking PETG.
PETG is not one of the filaments is lists as compatible, but it does list ABS

Simplify 3D Software
I've tried temps between 210 and 230
Speed setting is generally 2000 mm/min
Extruder Temp  - 220C (last attempt)
Material setting is ABS
Quality setting HIGH
Nozzle Diameter .4mm
Extrusion Multiplier 1.00
Extrusion Width .40mm
Infill Extrusion Width 140%
Build Platform Temp 60C
Print Support Every  1 layers
Infill- Rectilinear / Rectilinear
Layers/Outlines & Shells 5-5-3
Ooze Control Retraction YES
  Retraction Distance 1.0mm
  Retraction Speed 1200 mm/min


Here's the deal.....

Bottom layers seem to print great.   They are smooth, strong and look perfect basically.
The problem comes with the infill and the Support material.
Once it starts printing support material the print goes to hell in a hand basket.
It has a pretty hard time with Infill too.   With PLA the infill is sharp and clean and just totally precise.

With PETG the infill looks a bit sloppy and like it's saggy.

This is what my prints look like :-(
http://i1079.photobucket.com/albums/w512/urbansurvivalist/PETG_BadPrinting_zpsmfcgovec.jpg

Again, the Outline, Perimeter and Shell all look great.
I would describe the problem roughly as....
90% Support material
10% Infill

Can anyone please offer suggestions?
Thanks

2 Reply by carl_m1968 (edited by carl_m1968 2016-01-27 03:02:56)

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Re: Having a very hard time with PETG....

Slow down to 20mm per second (1200mm/m). PETG needs to print slow when it is being fed fast such as with infills. The issue I have with PETG are the little pieces that collect on the nozzle then burn and fall off into my print.. As long as it happens on the inside no big deal. But too many time it has happened on an exposed area.. Also turn your infill extrusion width down. It should never need to be more that 100% of your diameter. Turn the platform down to 60, your temp is way too hot for a platform. It should never be over 120 no matter what you are printing. Set your extrusion width to automatic or .48 which is what is proper for a .40 nozzle.

Unless your object has overhangs there is no need to have support even turned on..

The PETG I have prints at 265. Have you confirmed what your nozzle temp actually is versus what is reported? Are you sure your extruder is calibrated correctly?

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

3 Reply by poppinfresh (edited by poppinfresh 2016-01-27 03:16:35)

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Re: Having a very hard time with PETG....

Thanks Carl.

The 200 Platform temp was a typo.
Platform temp is 60C and EXTRUDER temp was 220C

I will try the other settings you suggested.

Thanks!

As far as the actual temp, do you mean at the nozzle?
If so, I have a laser thermometer right here so once I heat it up again I can check.
I  - think - the actual temps are higher than indicated because with PLA I always printed about 20 - 30C cooler than specified and it printed perfectly.  Setting the temps hotter resulted in strings and worse prints.

4 Reply by poppinfresh (edited by poppinfresh 2016-01-27 14:02:42)

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Re: Having a very hard time with PETG....

Well, thanks to Carl_m1968 and a lot of T&E, I finally got a fairly complex object with lots of supports to print reasonably well.  I printed at 230C and slowed down the print speed to 1000mm/min

It took a LONG time but completed successfully in some respects.

The biggest problem remaining is that support structures were VERY difficult to remove.  It took quite a fight to remove them and they left quite a mess on the printed object.  Compared to PLA, it's a nightmare.   It seems the PETG bonds so well, it bonds the support material as well. 

Support Settings....
Support Infill Percentage - 20%
Print Support Every - 1 layers
Horizontal offset from part - .4mm
Upper Vertical Separation Layers - 2
Lower Vertical Separation Layers - 1
Support Infill Angles - 45,


The bad news is that the object broke easily at one place, rendering the 8 hours of printing wasted.
Overall so far, I'm seeing no advantage to PETG but lots of disadvantages.

5 Reply by carl_m1968

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Re: Having a very hard time with PETG....

Heartlander wrote:

try your extruder at 265c, speed at 2800, bed at 90, infill 70 and no support. make sure to clean your bed every several prints. i use glass with hairspray. if i let it go too long or let the spray build up too much, i start having curl.

He said in another thread his extruder cannot do more than 260..

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

6 Reply by jagowilson (edited by jagowilson 2016-01-28 20:19:07)

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Re: Having a very hard time with PETG....

Heartlander wrote:

I missed that, Carl. Thanks. I now have set my extruder down to 260 and bed to 85 with no change in quality and no sticking/curling problems.

Don't mean to keep nagging you about this, but 260 is too hot for the PTFE in the Lite6. PETG will print at 245. If you need 260, buy a full E3D v6. Seriously, off-gassing PTFE is very bad for your health.

Please read:
https://en.wikipedia.org/wiki/Polymer_fume_fever

and stop putting yourself at risk of illness.

7 Reply by Heartlander (edited by Heartlander 2016-01-29 05:49:36)

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Re: Having a very hard time with PETG....

I suspect the thermistor is giving me exaggerated numbers since I put a glop of JB Weld hi-temp epoxy over the thermistor to keep it in place. I think it may reflect/refract heat back and create a hot spot. Anyway, if I try to print much cooler I start running into problems. But, I don't notice any off gassing at all.

I measured the heater block with my infrared thermometer (no good there) and a digital meat thermometer and the most consistent reading I got was 240 when the thermistor was reporting 265, so I don't know what to believe. 25 degrees is a helluva disparity but maybe I'm actually printing at 235c instead of 260.

But, I do appreciate your concern, amigo. Thanks. And I do run a fan and keep the door open.

P.S.: I deleted my prior posts where I said I was printing at 265 and 260 since I may be handing out free bad information. According to that Wiki article, out PTFE can start gassing at 232c! Sounds like a risky choice for a 240-rated hot end.

Robox printer, HICTOP (Prusa i3 variant) Model 3DP17 printer, ELEK 2.5W laser engraver, AutoDesk 123D Design, Windows 10

Heartlander's Website

8 Reply by Belcher (edited by Belcher 2016-10-08 13:14:56)

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Re: Having a very hard time with PETG....

jagowilson wrote:
Heartlander wrote:

I missed that, Carl. Thanks. I now have set my extruder down to 260 and bed to 85 with no change in quality and no sticking/curling problems.

Don't mean to keep nagging you about this, but 260 is too hot for the PTFE in the Lite6. PETG will print at 245. If you need 260, buy a full E3D v6. Seriously, off-gassing PTFE is very bad for your health.

Please read:

and stop putting yourself at risk of illness.

How it is bad for health?

Belcher's Website

9 Reply by carl_m1968 (edited by carl_m1968 2016-10-07 13:27:03)

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Re: Having a very hard time with PETG....

Belcher wrote:
jagowilson wrote:
Heartlander wrote:

I missed that, Carl. Thanks. I now have set my extruder down to 260 and bed to 85 with no change in quality and no sticking/curling problems.

Don't mean to keep nagging you about this, but 260 is too hot for the PTFE in the Lite6. PETG will print at 245. If you need 260, buy a full E3D v6. Seriously, off-gassing PTFE is very bad for your health.

Please read:
http://www.wordsiseek.com/

and stop putting yourself at risk of illness.

How it is bad for health?

It breaks down and gives off PTFE particulates as well as Flourine gas which is toxic in small amounts. However the PTFE use in the liteV6 should be stable at up to 300c.. But who knows for sure. I don't use hotends that have PTFE inserts that go into the hot side.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.