1

I have a problem when printing in ABS.

For some reason, I never seem to get the same results as many other people.

Whereas my prints in PLA, PETG, XT or Nylon all seem to be super strong, my ABS prints all seem to be much weaker. I now that when it comes to tensile strenght and such, ABS IS actually weaker than PLA or PETG, but this what I experience must be something else.

I was printing a model in grey ABS and even while printing, I noticed cracks appearing in the section where the walls get thinner (see picture).

Printing temp was 235 C at first, but I also tried 245. Bed temp is 70 degrees. The ABS flows nicely at both those temps. No fan is used while printing.

When the print is finished I can quite easily pull the prints apart along the print layers? Not only at the places where there are cracks, but even in those places where everything seems fine.

Is there something wrong with my particular type of ABS or am I doing something wrong??

ABS-Cracking.jpg
ABS-Cracking.jpg1024×768 79.3 KB

3 Likes
2

First of all, ABS is a really challenging material to print with. So don’t worry, the problems you are having are normal.

Here are a few tips which you can try to get better results:

- raise the bed temperature to 100 degrees Celsius

- enclose the build volume (reduces cooling rate of the part and thermal stresses)

- increase the hot end temperature (I’m printing ABS at 250° Celsius)

- decrease layer height (this is a general trick to improve layer adhesion)

- reduce infill (again reduces thermal stresses)

Good luck!

P

3

Hi P,

Thanks for the reply.

I have just finished printed the object again, this time at 245 C and 90 bed. Print is a little better but still much weaker than a similar print in PLA and ABS. Sometimes I don’t quite get why people keep saying that ABS is such a strong material. It certainly is more temp resistant than PLA, and a little more than PETG or Nylon, but in general, I find those materials stronger in basically every application.

Layer height is already down to 150 micron, infill is 22% and I don’t want to go any lower. The parts needs some strenght after all.

Will keep you guys posted.

4

Try raising the nozzle temperature even more. I print ABS at 254, heat bed 100 to 115 and just like you: no airflow preferably

5

I would try to use some glue stick if you have a removable build plate(otherwise you need to clean the surface always and it is difficult if the build plate is fixed). I never print ABS without a heated bed up to 90-degree celsius. however, my print result is always better with a glue stick even when I print relatively big objects as well. It is worth to try.

6

Like I said before: increase your temperatures!

Bed: 100 to 110 (or even 115 for all I care)

Nozzle: over 250 (I print at 255)

Your temperatures are too low as far as I’m concerned.

1 Like
7

Hi,

Your bed temperature is fine, also using no fan is good.

We usually print abs at 245 degrees,

Try using a smaller layer resolution and slowing the print rate down to say 45-50 mms

Hope this helps!

8

I have a solution:

Use this special ABS sheet. It is like “buildtac” but much cheaper and if you treat it nicely you can get more uses out of the same sheet.

How it works is that there is a layer of weaker ABS on a PCB sheet. The printed ABS filament bonds well to it, yet separates easily since the sheet’s ABS bond is weaker.

If you sit down and add up all the money and time wasted using tapes, sprays, and glues, it makes a lot more sense just to use a low cost sheet that will give you reliable results.

Want to try it out: buy it from here:

1 sheet: http://www.ebay.com.au/itm/191798568233?ssPageName=STRK:MESELX:IT&_trksi…

4 sheets: http://www.ebay.com.au/itm/191798569645?ssPageName=STRK:MESELX:IT&_trksi…

or contact for larger orders, custom sized sheets, etc: InventionFactory@debeers-education.com