PET - not pet-g

[curious aardvark]

A while back (couple years maybe) I bought a roll of pet-g from technology outlet.
When it came the reel said PET, Not pet-g.

It's odd stuff claims to be black but is kind of translucent grey.

And I've never really done anything with it.

So decided to give it a try yesterday, been making tripod inserts with adaptors for various cameras on top.
Figured I'd use the pet for the ipad holder.

So first i ran my filament test. Attached.
It's a small shape inside a larger shape. I place two a couple inches apart. This tests all the important things. The narrow gap between the two shapes tests short distance travel and retraction and the larger gap between the two models tests retraction over long distances.

My first pet settings : 23oc print, 50c bed, 75mm's print speed - pretty much hit the sweet spot.
Zero stringing, really clean prints.

And the properties of the PET were really interesting.

It's a lot more rigid than pet-g (which makes sense as glycol is a viscous liquid) and not as hard as pla. The small blocks were just about crushable, but did not split or shatter.
In pla the small shapes are just totally uncrushable and in pet-g they squish like hard chewing gum.

The larger shape in pet crushed, with some cracking and splitting - but NOT along layer lines.
Pet-g - the large shapes just squash and look chewed.
Pla - the larger shape resists until you put a lot of pressue on - then it explodes. Only did that once :-)

So pet is firmly in the sweet spot between pla and pet-g.
It prints easier than pla, and once I'd removed all squish from the print settings - sticks great to pei and removes pretty easy to.


Table confirms my 'slightly' less scientific testing ;-)

If I can get any more and it's a reasonable price - it could easily become my go to filament.

Quite why pet-g became the member of the polyethelene terepthalate family to become popular I don't really know.

Oh and this stuff has been sitiing on a shelf in my workshop for at least 2 years. No moisture issue.

My ipad mount builds out at a pretty steep angle - and was absolutely perfect at 0.3mm.

the base width is 43mm and the top width is 100 mm, with only 20mm vertical build.

ipad100.JPG

Even at 0.3mm layer height the underhangs were smooth and issue free.

Sooo, I'm currently printing one with 130mm width

ipad130.JPG

Still printing at 0.3mm :-)
So we'll see what the underhangs are like.
By rights they should work, but I'd expect them to be a litle rough. we'll see.
Might be able to go woder still - though the 100mm grips really well, so from apurely practical point of view I can't see anything wider than 130 being necessary.
But I am curious to see just how wide I can go :-)


It's a friction fit so the wider the arms the larger the area that's gripping the ipad. (it's an old ipad pro 9.7 my mate gave me - great camera)
Got a timelapse video of the 100 being printed, the ipad was being held in the 80mm first one.

Don't have alightning cable in here yet - so I'll upload later.

Right now to see if you can still get PET filament.

***

Yep - this looks about the best deal i can find: https://www.amazon.co.uk/ICE-Filamen...4420675&sr=8-6
only 750g, but at £18.99 - not an awful price.

And most stuff on amazon that just says PET in the title - is actually pet-g as it tells you in the description.

Oh and apparently it's hydrophobic - so zero moisture issues - ever !

I'll do some speed printing tests after this mount has finished.
But given how clean it prints at 75mm/s - I can't see any issued with 100 or 150 - we will find out :-)

On the 130mm mount front - there have been some crunchy noises coming from the printer. Print is still attached so i suspect I've had a little curling at the ends of the arms that are being caught on the metal, fan channelers. It Looks fine and print has not detached (what those noises usually precede) YET ! lol