PETG Drying

PaulHew

Well, I have just ordered from Amazon what Deckingman posted above from Susi.
Need to try something just incase, as Phaedrux and Deckingman have suggessted it might be damp..
I printed 6 PET-G parts last night and they all were weak and the slightest presure they snapped, like a twiglet.
The PET-G was stored in an air tight bucket with silica.

I am printing a pair in the PETG-G CF which I struggled with in another post, after it had been in the airing cupboard for over 24hours, and made sure my partner did not put her washing in there!

I found 2 of the original brackets I printed in PET-G 2 weeks ago, same manufacturer as of the snapped ones, applied the same sort of pressure as I had with the ones above and increased it and they did not snap, much much stronger.

Phaedrux

It really sounds like over cooling with the weakness between layers. Then It occured to me that the Ender 3 hotend fan blows quite a bit downward onto the parts through the gap around the heat block. Perhaps you could seal up the gap somehow.

I haven't printed PETG on my Ender 3 yet, but it seems like others do so without too much trouble. Is your ambient temp rather low? Perhaps a makeshift enclosure could help.

PaulHew

I am not running a part cooling fan, its about 18/19 deg C in my upstairs workshop.
This is my hotend.

Titan Aero's fan blow towards the heatsink, according to E3D that is correct.
This the outlet from the heatsink, all 4 edges.

I coud turn the fan around so it pulls the air through the heatsink.
The light blue parts were printed with the same hotend.

I had a delivery today, I shall craft an enclosure!

Phaedrux

Ah yes, you're using the Titan Aero, I forgot. I was thinking of the stock Ender.

Still, the Aero does blow downwards a bit. Especially with the stock fan. That thing is quite powerful.

Maybe give something like this a try?

https://www.thingiverse.com/thing:2325332

I used it myself before swapping the stock Aero fan for a Noctua.

PaulHew

@phaedrux Your a star, I shall print them tomorrow.
Wish I coulld buy you a beer or drop a bottle of your fave tipple round!
P.

DocTrucker

@paulhew said in PETG Drying:

Well, I have just ordered from Amazon what Deckingman posted above from Susi.

Bit late now but I ordered from ebay second hand. I did also find that Aldi are currently doing desktop convection ovens for £25. No use for drying below 70. It will allow me to heat up a second hand hotend assembly that's locked up with plastic and dry silica gel at 135C.

I've three spools of cheap black PLA that O've not used for an age that probably need drying that I will start with.

DocTrucker

If anyone else is interested in meadurong humidity have a read here:

http://www.kandrsmith.org/RJS/Misc/Hygrometers/calib_many.html

At a glance it appears the DHT22 isn't that great above 50% or a way from 25C.

PaulHew

No worries @DocTrucker , sometimes I would rather get something that will work and I have prime so free delivery and easy returns.

PaulHew

Update on Drying solution that @deckingman posted.
Bought the dehumidifier and 'cake' box.
Drilled 5 holes in the cake box and all goes together nicely.

Put a roll of PETG in it as it was giving me grief and within 5mins I could see moisture inside the chamber, not lots but noticable.
Took it out after 2 hours and tried again and printed first time.

Also thanks to @OBELIKS for the drying times, very useful.

deckingman

@paulhew Glad that worked for you. It's still on my todo list to try (it's coming up 2 years since Susi sent me the info)