2
$\begingroup$

I use a Prusa i3, and this is ABS printed part with 225/90°C. Why did this happen?

First ABS print - image#1 First ABS print - image#2 First ABS print - image#3 First ABS print - image#4

I tried to print this part again with new settings on Slic3r (I used Cura for previous print), but I got the same result. I found that the problem is because the model starts to bend after about 1 cm height. Also the blue tape starts to separate from the bed.

I don't use the fan for printing part (although the MK8 extruder's fan works all the time), and the temperature for the new part was (225/85°C first layer and 220/80°C for other layers). Also I must say that the adhesion of the model sticks to the bed is very good and strong, but it is bent!

Second ABS print - image#1 Second ABS print - image#2

$\endgroup$
  • 1
    $\begingroup$ ABS is a royal pain to work with. About all I can suggest is to build an enclosure and try to keep the entire workspace (air volume) as warm as possible $\endgroup$ – Carl Witthoft Nov 27 '17 at 16:29
  • $\begingroup$ Enclosing Prusa i3 completely puts mainboard and PSU at the risk of overheating. Don't do it before you ensure proper cooling for your electronics. $\endgroup$ – ZuOverture Nov 29 '17 at 6:19
  • $\begingroup$ @user145959 tapes unstick after long periods of heating. High temperatures are good only for first layer to get adhesion. $\endgroup$ – Fernando Baltazar Nov 30 '17 at 18:32
4
$\begingroup$

Multiple problems here. Let's try to isolate them.

  • Blue tape. Good for PLA, not suitable for ABS. ABS works fine with kapton tape, glue stick, hair spray, ABS juice over glass, aluminum or PCB epoxy composite board.
  • Always use at least brim feature to ensure good adhesion along the edges (your last photos have none). For parts with small hotbed contact area use raft.
  • Hotbed temperature should be 100°C+, because at 80°C adhesion is weaker. If you can't raise hotbed temperature to 100°C, think about thermal insulation.
  • Layers of plastic don't stick to each other. Either plastic comes from extruder being already cold (check that there are no draughts of cold air nearby), or you're printing too fast (50 mm/s should generally work, if not try 30 mm/s).
  • No infill between walls. Either it is set to 0 or optimized out by some option.
  • Round walls aren't round. Either printing speed problem, or your belts are loose.
  • Underextrusion. Bottom of your first print looks like mesh rather than solid surface. Check that plastic flow is around 100%.

Also check that your thermoresistor measures the actual temperature of the extruder (i.e. is in direct contact with it). Otherwise you will get overheated plastic extrusion, which looks like your first photos.

Also, print a 1 cm cube first. Don't do anything complex, just cube.

| improve this answer | |
$\endgroup$
2
$\begingroup$

My best results with ABS have been with a hot bed (100 degrees C), and using the "acetone/ABS slurry" to stick the print to the bed.

I was not able to get ABS to stick well enough to blue tape at low bed temperatures, and at high bed temperatures the blue tape would sometimes separate from the bed.

The ABS slurry is applied to the cold bed, and gives you an ABS film intimately attached to the bed. It will be a thick enough film to carry the color, so it is best to make the slurry with the same color as you will be printing with. There is no absolute ration of acetone to ABS that should be used for the mixture. In service, the acetone evaporates. A thicker slurry will leave a thicker coating.

I use flux brushes (sometimes called acid brushes) to apply the slurry, although one can also use a watercolor brush, or just pour a small puddle on a bed if it is level enough to not run off the edge.

| improve this answer | |
$\endgroup$
1
$\begingroup$

Try putting your printer into a heated chamber, and when the print is finished, slowly decrease the temperature of the chamber. I would also recommend using putting something like buildtak or printbite onto your buildplate. If you are not able to do that I would recommend putting some purple gluestick onto the bed, or a few spritz of hairspray should do the trick.

| improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.