ABS or PETG

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psd
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ABS or PETG

Post by psd » Tue May 03, 2016 8:50 pm

Which filament is a better all around filament?
Would you go with ABS or PETG?

Do they both have similar strength characteristics?


I assume that PC is too problematic with warps.

PLA is good but not so resistant to temperature or humidity,

so what is the material of choice for 90% of prints?
- peter,

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www.petersolomondesign.com

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Jules
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Re: ABS or PETG

Post by Jules » Tue May 03, 2016 9:19 pm

If the temp matters I use PETG.

For strength, believe it or not, PLA is hard to beat at high infill. (When I first got here, one of the experts did a fantastic stress test on all 3 filaments with buckets of water.......can't remember now which one of the guys did it, (old age setting in), but it's worth trying to find that thread, cause it was a fascinating result. PETG tends to separate by delamination, but PLA doesn't.)

I've got a roll of ABS, but never cracked it. That requires an enclosure for keeping the cracks and warping down, and it stinks, which tends to distress my better half. (Allergic to everything, poor baby.)

PETG has it's downside though - total crap on bridging, and the stickiness of the filament requires some care be taken with the nozzle height or you wind up with blackened bits in your print.

Also - I think Justine was recently getting pretty good experiences with the PC using a PEI surface to hold it in place and cut down on the warping.

(Check out the other posts in the Filaments section of the forum.......there are a lot of good write-ups in there.) :D
Last edited by Jules on Tue May 03, 2016 9:22 pm, edited 1 time in total.

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zemlin
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Re: ABS or PETG

Post by zemlin » Tue May 03, 2016 9:21 pm

I've only printed a few parts in PC, but at 100C on PEI over aluminum I'm getting good adhesion - that was with eSun. I have a spool of black PC from Gizmo Dorks coming. In the testing I've done (bending round test rods) PC is the strongest of the materials I've tested and it prints cleaner than PETG, but costs about twice as much as more standard materials. I have not tested PLA for strength, as it's not an option for my current projects due to temperature requirements.

I like PETG - but it's a fine line between over extruding and getting blobs, and under extruding to get gaps between perimeters. Strength seems similar to ABS in my tests, but I have not had great luck with ABS.

The biggest issue I have with ABS is bonding strength between layers which leads to delamination and poor part strength.

Nylon hasn't won me over. It's strong enough, but my prints have been fairly ugly with it. Lots of variation in the filament diameter so the surface quality is inconsistent.

If I want a part to look good, I use PLA. Haven't had anything print prettier.

psd
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Re: ABS or PETG

Post by psd » Tue May 03, 2016 9:24 pm

Jules wrote:If the temp matters I use PETG.

For strength, believe it or not, PLA is hard to beat at high infill. (When I first got here, one of the experts did a fantastic stress test on all 3 filaments with buckets of water.......can't remember now which one of the guys did it, (old age setting in), but it's worth trying to find that thread, cause it was a fascinating result. PETG tends to separate by delamination, but PLA doesn't.)

I've got a roll of ABS, but never cracked it. That requires an enclosure for keeping the cracks and warping down, and it stinks, which tends to distress my better half. (Allergic to everything, poor baby.)

PETG has it's downside though - total crap on bridging, and the stickiness of the filament requires some care be taken with the nozzle height or you wind up with blackened bits in your print.

Also - I think Justine was recently getting pretty good experiences with the PC using a PEI surface to hold it in place and cut down on the warping.

(Check out the Filaments section of the forum.......there are a lot of good write-ups in there.) :D

I have been reading through the Filaments section of the forum.
I had recently ordered some ABS from MakerGear and it looks like I am going to try to sell it, anyone want it?

I don't have an enclosure. Looks like I will have to stick with PLA and PETG. I thought PLA was just for temporary uses.

I do have a PEI surface so maybe I will try PC. I would like a material that after a bit of fine tuning I don't have to fuss with any more....

What are you printing with a dual head? What is your nobel material and what is your soluble material? PETG and PLA
- peter,

innovative product designer and tinkerer

www.petersolomondesign.com

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Jules
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Re: ABS or PETG

Post by Jules » Tue May 03, 2016 9:49 pm

psd wrote:I don't have an enclosure. Looks like I will have to stick with PLA and PETG. I thought PLA was just for temporary uses.
You can do smaller ABS prints without an enclosure, but the taller the print gets, the more likely it is to crack without an enclosure. I wouldn't sell it, you might like it, and who knows, next year might be the year that we get the enclosure upgrade for ABS. (Nope, don't know anything, just been around long enough to anticipate cool surprises from this crew. :lol: )
What are you printing with a dual head? What is your nobel material and what is your soluble material? PETG and PLA
I tend to print more in PLA, because i like the finish, and most of what i need it for is just little throw-away stuff, and I've got about 20 rolls of it in different colors. :roll: The solid color PETG is what I use for anything that requires staying power (replacement parts for the machine, etc.).

So generally, I run PLA through one nozzle and PETG through the other. PLA makes a fantastic support material for PETG. They don't bond and the two surfaces just snap apart with zero drama. You can use zero separation and get a great underside on the PETG print with overhangs. It also works the other way, but not quite as well, since the PETG prints hotter. (PLA doesn't dissolve though, so if it absolutely can't be removed except by dissolving it out, I'll run PVA. Don't care for it much though.)

You can run any filament through the dual, the woods, the metals, and I've got a spool of PC and one of semi-Flex that I plan to get around to testing one day. Others have tested them though, so we know they work.

The Dual really opens these things up.

psd
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Re: ABS or PETG

Post by psd » Tue May 03, 2016 10:20 pm

(PLA doesn't dissolve though, so if it absolutely can't be removed except by dissolving it out, I'll run PVA. Don't care for it much though.)

wow, I thought the PLA was the dissolvable support in our previous Dimension Stsratasys.
Maybe it was PVA, doe PVA not make a good soluble support system then?

I really liked building models completely encased in support and dissolving it away, always got a great surface finish and no risk of remnants.
- peter,

innovative product designer and tinkerer

www.petersolomondesign.com

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Jules
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Re: ABS or PETG

Post by Jules » Tue May 03, 2016 10:53 pm

PVA is the dissolving one - (in water). I had a really tough time getting PVA to stick where I wanted it to, although it clung like a limpet to everything else. (Like I said, I'm not a fan, especially given how expensive it is.)

But some of the other guys, (tim, insta, jin ) look like they had a lot better luck with it so they can give you more details when they log on. Tim did one of those totally encased prints on a chess piece, but I'm a bit of a tight wad....I refuse to waste filament that's twice the price of the next best thing, especially if the next best provides better support.

It's just personal preference, having tried both, if I have a choice and I can get to the support at all with a tool, I'll choose PLA over PVA for support.

Your mileage may vary....only way to know is to try it and see....... :lol:

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jimc
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Re: ABS or PETG

Post by jimc » Wed May 04, 2016 1:12 am

zemlin, interested to see what you think of the black gizmo dorks pc. i have printed a ton of the epc and its really great but would like to hear someones comparison who has used both. pc is generally the most warp happy plastic there is but esun managed to get that all under control. i also like the fact that its flame retardant. that great for hot end parts, filament drives, etc.

as for abs, it generally will always break along a layer line. petg layer bonds and fuses into one piece. abs doesnt really. i have tried atleast a dozen different mfg of abs over the last few years and they can all be separated or broken along layers if you try. overall its generally pretty strong though.

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zemlin
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Re: ABS or PETG

Post by zemlin » Wed May 04, 2016 12:37 pm

jimc wrote:as for abs, it generally will always break along a layer line. petg layer bonds and fuses into one piece. abs doesnt really. i have tried atleast a dozen different mfg of abs over the last few years and they can all be separated or broken along layers if you try. overall its generally pretty strong though.
Last night I switched over to a .5mm nozzle to print some parts, and ran a few of my 13mm test rods for bending strength. I'll have to check out the differences between colors alone, but it appears that the bending strength of PETG parts sees a huge improvement with the larger nozzle. Laying down more outlines with the .35mm nozzle did not improve the part strength.

The parts I ran were with the .5mm nozzle extruding to .7mm (a little wide, but was dialing in some gap filling) and a .35mm layer. Bending tests with the .35 nozzle parts in black failed at 2.8 kg. force at the end of the cheater bar. The .5mm nozzle parts pegged the scale at 5 kg, so I don't know the force, but when I finally snapped a part it was across the layer boundary for about half the diameter and then a lovely fracture for the other half.

Now I'm curious to see if ABS and PC see similar strength benefits with the larger nozzle and layers. Will also test black PETG.

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jimc
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Re: ABS or PETG

Post by jimc » Wed May 04, 2016 1:04 pm

Your additional layer bonding strength is probably more from extruding such a wide line compared to your nozzle dia and layer height. You are really squishing those extrusions together with those settings. I have done similar tests in the past and have found that petg fractures across the layer lines, not along them. My breaks were more like if i cracked a piece of plexiglass. That is assuming i have the temp right.

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