ABS brittle etc???

[dunginhawk]

So Im working with a brand new roll of filament (abs) that came with my new printer... I think its bad
Would the qualities of bad abs filament be brittleness? Because I printed it out at 240 degrees (10 higher than normal) and it came out looking ok, but cracked easy and was very easy to snap. would that be the 10 degrees? or poor quality filament?
Just curious.. as im having a serious issue with cracking with this filament

[DavidF]

What do you mean by cracked? Separated between layers?
have a picture?

[DavidF]

Try burning a small piece of it and see if it burns clean with a blue flame, or black and smokey.

[dunginhawk]

yeah separation between layers... and with my other ABS the part is strong and very robust... this cracked, and broke easily

black and smokey

[dunginhawk]

really hope its the filament and not something else..
so its a 5-8 hour print, and im running it at 50-60mm/s print speed, which isnt too fast, so i wouldnt think thats too fast.

[DavidF]

I mostly print in pla, so im afraid i wont be much help. But im thinking you need to slow down to 30mm/sec and see what you get then.

[dunginhawk]

I may have to try that, but i do think id kill myself if i had go from 60mm/s or more down to 30 haha.

[DavidF]

slow and steady wins the race

[dunginhawk]

slow and steady does not win this race

[DavidF]

you can live your life a 1/4 mile at a time, but im looking for mileage

[0110-m-p]

60mm/s is too fast in my book for a ABS without a full enclosure (and probably too fast for that too). Depending on the size of the part I print ABS with 0.2mm layers and a 0.4mm nozzle at 30-40mm/s. If you want to print fast, you need to use PLA.

Also, hotter is usually better for layer adhesion and will help keep a print from splitting.

EDIT: I'm curious though...what brand/color ABS is it?

[JFettig]

I would definitely say its a speed issue. The layer printing doesn't get enough energy into the previous layer to get a good bond. Not having an enclosure I experienced quite a few 'brittle' ABS prints. now that I have an enclosure on my printer, its printing very nicely. Infill also has had an effect on strength.

Jon

[dunginhawk]

So i do have a full enclosure on one of my printers, which im using. IM running first layer around 40mm/s the others at 60.

This brand is flashforge filament red.

it finished ok and the later layers were ok, so perhaps it wasnt the filament, but instead the speed of that first layer...
I sped it up mostly because I was testing the brim settings to get this giant piece to adhere without curling..

My new brim worked... I made 4 rectanglers .2mm high in 123design and brought them in to simplify3d... put them under the main print (overlapping a couple mm) so its a stronger brim than i was getting before..
worked really nice, and had no curling.

[JFettig]

Be patient with the 1st layer, its the most important layer in the whole thing. I run my 1st layer at 20mm/s, 35-40mm/s for the rest in ABS, at 235C generally.

[dunginhawk]

Yeah i may need to try that with my next print... Even with a brim, the corner (not of the brim, of the print) is still turning up..
110c bed, 230c temp. full enclosure. PEI bed sanded and rubbed with acetone..

its bizarre that a corner can pull up, yet its absolutely insane how hard it is to get the print off of this PEI... its crazy

[dunginhawk]

so im trying this print now at like 15mm/s for the first layer.. not even sure its going that fast... think something is wrong with simplify 3d.
either way its a 14 hour print at the speeds im at now...

[dunginhawk]

so the first layer is so slow in fact its been over 1 hour and its only about 3/4 done...
its 7.2 inches x 5... with a brim...

[DavidF]

thats the wonderful thing about 3d printers, you can go to be and wak up to your finished part in the morning (or somedays spagetti )

[dunginhawk]

except ill wake up and still have 8 hours left haha.
i mean there is NO WAY this is printing 25mm/s no way in heck.
something is definately not right... but its putting down an AMAZING layer... i just cant afford to do a 14 hour print haha

[DavidF]

sounds like the perfect reason to sleep in.

[dunginhawk]

whole kids up at 6am to eat thing get in the way, and job too... haha.

[dunginhawk]

well, woke up this morning and a couple corners are STILL curling up, with the brim, with the 110c bed (measured it at 104 in one of the corners, through the layer and PEI), and with 10mm/s first layer, and 20mm/s all other layers.

Im at my wits end

[0110-m-p]

Could you post some pictures?

[dunginhawk]

As you can see this has to be pretty strong to pull up a brim like that... Crazy thing is this PEI at 110c holds this part SOOOO well in every other spot that I literally have a VERY hard time getting it off the plate. like 10 minutes of work.


[img]http://i1132.photobucket.com/albums/m562/dunginhawk/A4DCF284-29D8-4415-95C6-130246C29997_zpsxaeden46.jpg[/img]

[img]http://i1132.photobucket.com/albums/m562/dunginhawk/B7ED25C4-2E80-489B-B086-C5E8D614C6C6_zpswgqyqvue.jpg[/img]

[JFettig]

Have you tried printing on top of a raft?

When I first started with PEI I had it around 105C and had the same problems getting parts off. Even at 90C I have a hard time getting parts off the PEI unless I print on top of a raft. I also don't have any issues with corners coming up on a raft which is nice.

The downside to the raft with large parts is that its huge and takes a long time to print.