PETG or PLA?

ge_rik

British narrow gauge (esp. Southwold and W&LLR)
24 Oct 2009
10,095
1,114
Cheshire
www.riksrailway.blogspot.com
Country flag
I notice that LGB-Sid LGB-Sid among others now uses PETG for his prints eg - What have you been printing.

I'm sure I'm not the only person to have concerns about using PLA for models in an outdoor environment. I've tried spectacularly unsuccessfully to print with ABS and see that PETG seems to have many of the advantages of PLA (eg adhesion to bed, lack of odour when printing) without the disadvantages ( ie biodegradability).

Just wondered what people's experiences with it were and how it compares with PLA in terms of preparing the printer.

Rik
 

ge_rik

British narrow gauge (esp. Southwold and W&LLR)
24 Oct 2009
10,095
1,114
Cheshire
www.riksrailway.blogspot.com
Country flag

LGB-Sid

Registered
19 Sep 2016
1,522
943
62
UK
Country flag
Hi rik everything I print is in PETG now, I have had stuff printed in it now for three years left outside permanently and there doesn't seem to be any change in things, I do paint everything, unlike the PLA things I have tried that failed left outside. The one disadvantage with PETG is it likes to stick to everything while printing, the bed, itself, the nozel it comes out off :), some things can be a bugger to actually get off the bed if you have left it overnight to print, I have had to warm the bed up again to get the print off :rofl:

It took awhile to find the correct settings and temps for my printer to get it to print, I use one made by Eryone found on Amazon, not saying its the best, but I have found that once you have your machine setup to suit a filament then it's best to stick with the same maker especially with PETG.

I can print quite happily with the printers in the house without horrible plastic smells coming from the printer , as you say not so with ABS. If you design the parts to suit, then you can get some good strong parts with it, all my locos , Wagons, Signal boxes and soon to be carriages, are printed with it. The other advantage of PTEG over ABS is less warping during printing

 
  • Like
Reactions: 1 user

LGB-Sid

Registered
19 Sep 2016
1,522
943
62
UK
Country flag

ge_rik

British narrow gauge (esp. Southwold and W&LLR)
24 Oct 2009
10,095
1,114
Cheshire
www.riksrailway.blogspot.com
Country flag
Hi rik everything I print is in PETG now, I have had stuff printed in it now for three years left outside permanently and there doesn't seem to be any change in things, I do paint everything, unlike the PLA things I have tried that failed left outside. The one disadvantage with PETG is it likes to stick to everything while printing, the bed, itself, the nozel it comes out off :), some things can be a bugger to actually get off the bed if you have left it overnight to print, I have had to warm the bed up again to get the print off :rofl:

It took awhile to find the correct settings and temps for my printer to get it to print, I use one made by Eryone found on Amazon, not saying its the best, but I have found that once you have your machine setup to suit a filament then it's best to stick with the same maker especially with PETG.

I can print quite happily with the printers in the house without horrible plastic smells coming from the printer , as you say not so with ABS. If you design the parts to suit, then you can get some good strong parts with it, all my locos , Wagons, Signal boxes and soon to be carriages, are printed with it. The other advantage of PTEG over ABS is less warping during printing

Thanks Sid. That's really encouraging, particularly as I too use an Eryone (Thinker SE).
Are you still using the Eryone glass bed? Mine lost its stickiness so I've flipped it over and now use Pritt with my PLA printing.

Rik

Flippin predictive text on this tablet - it changed 'Sid' to 'Sir' and 'Pritt' to 'Print'...... Unless, Sid, it knows something about you that the rest of us don't know .... ;)
 
Last edited:

LGB-Sid

Registered
19 Sep 2016
1,522
943
62
UK
Country flag
rik I Print on a bed with 3M painters tape on it, as it sticks to it well, and as I print large surface areas in contact with the bed its easier to get things off for me. My Printer is fully enclosed and has a fixed Print bed so access can be a pain to remove things sometimes.
 

LGB-Sid

Registered
19 Sep 2016
1,522
943
62
UK
Country flag
Have now ordered some Eryone PETG which was on offer on Amazon. I'll let you know how I get on.

Rik
Got a reel yesterday as it was on Offer as well :)
 

beavercreek

Travel, Art, Theatre, Music, Photography, Trains
24 Oct 2009
17,551
678
East Anglia
www.facebook.com
Country flag
Hi LGB-Sid and Ge-Rik. A few weeks back I picked up a CTC dual extruder printer from '3-Minutes of Fame' (Matt). He was giving it away and was kind enough to take me through some basics of the art of 3D-Printing, he does quite of a lot printing which is of really nice qualit (he has posted some of his exploits on the forum).

He showed me an item that he created with wood impregnated PLA (a Groot figure). The item had been outside for a few years in a pond and seemed to have lasted well.
I am reading your thoughts on PLA and using it for outside items.
As I will be using the printer for making parts and replacements for broken items on rolling stock and also figures and building detail, the fact that they might degrade due to UV and possibly very hot days (memories of the bliss of last summer) does drop an item of concern into the melting pot (sorry!).

But as a very much newbie to 3D printing, the idea of making the print process (with using PETG) even a bit more complex can seem daunting.

Have you any experience with the CTC printer?
 
  • Like
Reactions: 1 user

LGB-Sid

Registered
19 Sep 2016
1,522
943
62
UK
Country flag
Hi I have not used a CTC printer ?, you have one advantage over me if it has duel extrudes, as one thing PETG does is stick well to itself so supports are hard to remove in a lot of cases, so I design to avoid supports where ever possible. You can use a suitable filament in your second extruder for support work, which would make life a lot easier.Some of my failures were down to heat, I got a fair amount of delaying on things left out overtime printed with PLA, but probably there were bad prints or poor PLA filament, not sure but since I found PETG I have stuck with it.
 

ge_rik

British narrow gauge (esp. Southwold and W&LLR)
24 Oct 2009
10,095
1,114
Cheshire
www.riksrailway.blogspot.com
Country flag
Hi Mike
My smaller printer is a CTC, but it's an Anet A8 clone with a single extruder, so I doubt if it compares. So far not tried PETG with either printer so can't really comment. I'm quite happy with the results I've got with PLA so far.

I did a bit of digging and discovered that while PLA does biodegrade, it can take between 100 and 1000 years to do so when buried in landfill, so I think it'll outlast me - just.... !

Rik
 
  • Like
Reactions: 1 user

musket the dog

Registered
31 Oct 2009
734
118
Leicester
nlrr.webs.com
Country flag
I don't have experience in printing PETG but I have used the material a lot in my day job where it (or very close relatives) is commonly used for blow mouldings like the big coolant expansion bottles on your car.

It's worth remembering that all the materials we are able to print with will be effected by UV and perhaps more importantly for us in the UK, moisture. The best way to protect them (without being able to blend in other materials) is to make sure they are well painted. Normal automotive paints and primers should do a fine job. My experience is that PETG has to be very well primed in order to take paint.

I have printed with PLA and ABS so far, and have gotten to a point where I am happy with what I can produce down to OO scale. I do plan to have a go with PETG to see how I fare. For every new material you introduce to the printer will need you to do some tweaking to find the perfect settings for your environment. That counts for different suppliers versions of the same materials too. Even the same material, from the same supplier, in different colours might need some fine adjustment. The issue is that terms like PLA, ABS, PETG are all quite generic. There's a lot of chemistry beyond that that changes from supplier to supplier. My advice would be to find a good quality material and once you get it to work for you stick with it.

It seems daunting at first but it's just a case of trail and error to begin with. There are a lot of useful guides and test parts from the likes of all3dp.com and Thingiverse. There should be some good base settings with the material or on your slicer program. Then it's just a case of picking a test part you like and tweaking one setting at a time until you have success :)
 
  • Like
Reactions: 1 user

3 minutes of fame

3d printing, electronics and trams
14 Dec 2020
202
73
Lincolnshire
www.mgnr.uk
Country flag
beavercreek beavercreek , that CTC prints PETG very well. I've done some rocket sweetie boxes in it and we have a bird box that's been outside for 2 years with no visible degradation.

I found playing with the print temp - maybe go up 10 degrees from PLA tends to work well. The Print Tak bed I gave you will adhere very well to the PLA, but provided you don't "squish" it down too much, it should come back off cleanly.

PLA will last a couple of seasons outdoors. a layer of varnish helps, but as you could see from the wooden groot and the fence post toppers, you can print inwood infused PLA and it will last very well indeed.

ABS is smelly to print with, but can give excellent results. delamination is the main risk if the cooling is wrong, but other than that, I had very few problems with it.
 
  • Like
Reactions: 1 user

beavercreek

Travel, Art, Theatre, Music, Photography, Trains
24 Oct 2009
17,551
678
East Anglia
www.facebook.com
Country flag
beavercreek beavercreek , that CTC prints PETG very well. I've done some rocket sweetie boxes in it and we have a bird box that's been outside for 2 years with no visible degradation.

I found playing with the print temp - maybe go up 10 degrees from PLA tends to work well. The Print Tak bed I gave you will adhere very well to the PLA, but provided you don't "squish" it down too much, it should come back off cleanly.

PLA will last a couple of seasons outdoors. a layer of varnish helps, but as you could see from the wooden groot and the fence post toppers, you can print inwood infused PLA and it will last very well indeed.

ABS is smelly to print with, but can give excellent results. delamination is the main risk if the cooling is wrong, but other than that, I had very few problems with it.
Thanks Matt, that does allay my fears of using PETG and also how to delay PLA from degrading outside.
I think that I remember you saying that the wood impregnated PLA can be a bit inconsistent in width and become stuck in the nozzle.

The building details etc that I want to create are probably the ones that will have to stand up to the rigours of UV, moisture and temperature.
I will also be doing some complete small buildings, like outhouses, line-side huts etc.

How would PETG, PLA or ABS stand up against commercial self coloured plastic kits like Pola and Piko as I have some of those that have been outside for 15 years now and the only degradation is a bit of brittleness on the details and a bit of colour lightening here and there and a loss of any gloss on the plastic (handy that it looks just like weathering!).

I have a couple of small resin kit buildings and the walls have warped somewhat through the years.
 

justme igor

Registered
17 Apr 2020
297
32
Netherlands Westwoud
Country
Netherlands
Country flag
I'm sure I'm not the only person to have concerns about using PLA for models in an outdoor environment. I've tried spectacularly unsuccessfully to print with ABS and see that PETG seems to have many of the advantages of PLA (eg adhesion to bed, lack of odour when printing) without the disadvantages ( ie biodegradability).
Pla will shrink 5 to 10% outdoors, it will take years to deteriorate, many years.
I have same pieces in the garden for over two years now, they only shrunk a little.

ABS is quite simple to print, dont even breath at it at 3 foot/1 meter from it.
This was rule number one if it is not in a enclosure.
Even a radiator (thermal air displacement) can influence on the stickiness of the print to the bed.
So disable your fans also!
Dont open the door to the room where the printer is in.
With other words no air distortion.

Rule number two:
Leveling and a first thick layer at slow speed(My setting: 0.3mm thick and 30mm/s)
Experiment with temperature, increase first your bed from 90 with 10 celcius at the time.
Than your nozzle temp from 200 with 10c at the time.
My setting: 240 nozzle and 90 bed.

Create a stl file for instance: a sleeper.
Cheap and a quick print.
Look for a temp tower on thingiverse to save some time but it will take away some learning curve.

Hope this will get you a bit where you want. Yes try and error, ABS that is...hmmmm
 
  • Like
Reactions: 1 user

beavercreek

Travel, Art, Theatre, Music, Photography, Trains
24 Oct 2009
17,551
678
East Anglia
www.facebook.com
Country flag
Just seen this on a G scale Facebook forum about using PLA for garden railways and the problems of exposure to heat etc.:

"So a bit of an update on 3D printing with garden trains. I have found that PLA is fantastic for printing up stuff that stays indoors. I have made a few items for my N scale mini layout and they are great. I tried to make some small 4 wheel ore cars for my garden railroad in PLA, and they too looked great, that is, until the first day when temps hit over 80 degrees. Then the things melted in the sun. The only thing salvageable were the Kadee couplers and the wheel sets.
I am now learning how to print with ABS. It has a much higher heat tolerance, but in exchange, its a bear to print. It does not stick to the print bed very easy and will begin to lift up on one edge. I purchased some liquid coatings and am now experimenting with these to hold the print in place. Results are mixed, but I seem to have found one by the name of Bedweld. It sticks to the bed very well and once the bed has cooled down, it just pops off. I will keep you all updated on the progress."
 
Last edited:

PBinLostAngeles

Registered
28 Jan 2021
2
1
64
Port of Los Angeles
Country flag
While I remain a rookie/newbie in the model train world, I'm no stranger to 3d printing, going back to its infancy - I worked in Standard Tooling Engineering on the B-2.
That said, as you seem to have found out - fundamentally speaking - compared to other filaments, where you might have a problem with bed adhesion, most people see the complete opposite with PETG. A material, which, by its nature, will stick hard to a bed. I've seen it adhere so hard sometimes, that a piece of the bed would come off with the print piece. Try a protective layer on your bed for PETG. In the Northrop labs, they used everything from glue sticks to blue masking tape.
Based on what you shared, clearly you've learned that with PLA, you’ve got to ensure that the gap between the nozzle and bed is tight - PETG is different: it needs a decent gap. For example, when printing with PLA, you've been setting your nozzle-to-bed gap @ .004+/- the nozzle-to-bed gap S/B .012+/- for PETG...These are +/- tolerance parameters, not exact settings.
While I've seen PETG print ops without a heated bed, the model makers our department supported eventually went to using heated beds every time out. Set between about 158 degrees F and 180 degrees F, with experiments going as high as a starting bed temp of 210+/- degrees F....
In the early days, on a "cold start" morning, the engineers would generally begin with about 158 degrees F - gradually increasing temp as - or if - they encountered bed adhesion problems. While not specifically applicable, perhaps these tolerances will help as point of reference, perhaps not....
 
  • Like
Reactions: 1 user

ge_rik

British narrow gauge (esp. Southwold and W&LLR)
24 Oct 2009
10,095
1,114
Cheshire
www.riksrailway.blogspot.com
Country flag
While I remain a rookie/newbie in the model train world, I'm no stranger to 3d printing, going back to its infancy - I worked in Standard Tooling Engineering on the B-2.
That said, as you seem to have found out - fundamentally speaking - compared to other filaments, where you might have a problem with bed adhesion, most people see the complete opposite with PETG. A material, which, by its nature, will stick hard to a bed. I've seen it adhere so hard sometimes, that a piece of the bed would come off with the print piece. Try a protective layer on your bed for PETG. In the Northrop labs, they used everything from glue sticks to blue masking tape.
Based on what you shared, clearly you've learned that with PLA, you’ve got to ensure that the gap between the nozzle and bed is tight - PETG is different: it needs a decent gap. For example, when printing with PLA, you've been setting your nozzle-to-bed gap @ .004+/- the nozzle-to-bed gap S/B .012+/- for PETG...These are +/- tolerance parameters, not exact settings.
While I've seen PETG print ops without a heated bed, the model makers our department supported eventually went to using heated beds every time out. Set between about 158 degrees F and 180 degrees F, with experiments going as high as a starting bed temp of 210+/- degrees F....
In the early days, on a "cold start" morning, the engineers would generally begin with about 158 degrees F - gradually increasing temp as - or if - they encountered bed adhesion problems. While not specifically applicable, perhaps these tolerances will help as point of reference, perhaps not....
That's really helpful, thanks.
In layman's terms, does 4 thou equate to printer paper and 12 thou equate to card?

Rik
 

PBinLostAngeles

Registered
28 Jan 2021
2
1
64
Port of Los Angeles
Country flag
That's really helpful, thanks.
In layman's terms, does 4 thou equate to printer paper and 12 thou equate to card?

Rik
I use feeler/gap gauges, they're more "truthful" and your can of course, use reliably again and again.... Pick up a cheap set at any auto supply or Harbor Freight Tools
That's really helpful, thanks.
In layman's terms, does 4 thou equate to printer paper and 12 thou equate to card?

Rik
I use feeler gages. Paper isn't always reliable and the difference in thickness - even within the same feeler-gauge.jpg ream - is often tangible.
 

justme igor

Registered
17 Apr 2020
297
32
Netherlands Westwoud
Country
Netherlands
Country flag
I use feeler gages. Paper isn't always reliable and the difference in thickness - even within the same feeler-gauge.jpg ream - is often tangible.
Yes paper is measured in gr a m2.
Always stick to ONE piece of paper and adjust your printer to that.
Gauges are better.

If your print does not stick your space between the nozzle and bed is to big.
And yes use a decent sticking spray...glue stuff and hairspray...willl.....can...work...do..the..job.....

Level your bed and figure out the distance between your nozzle and bed, adjust to that...
To close: get a chisel to get your ABS print of the bed....if you wont break the temperd glass of course
To far away: it wont stick...simple.
Use a simple adhesive, and not the cheap look a likes like glue patrons or what ever.
Secret to ABS i told you everything...there is no secret.
Read my former post please, it is not difficult, just sit down and have a nice and good conversation with your printer...with a sledgehammer if you have to...but that one is for you :cool:
If the nozzle is to close towards the bed take a chisel to get your print off...to far away you will get spaghetti.
Take your time to adjust your temps according to what your printer likes. and the brand of ABS likes..its not only the steak you are eating...bit of salt...bit of pepper, some parselie, fresh pig belly fat...maybe a touch of garlic...
Ofcourse pepper before salt....

With best regards Igor

My former post:
Post #15 in this topic.
 
  • Like
Reactions: 1 user