Layer Delamination

I'm having some layer delamination issues. I read that this can be caused by drafts, so I cut a cardboard box to fit over the top of the machine. The box wasn't big enough to fully encapsulate the printer and let it work, so I cut slots for the print bed to protrude through and the top is somewhat open. I also read that it can be caused by too low of a print temperature so I turned up the temperature from 225°F. The layers kept splitting though. I attempted to make the skirt the same height as my print subject, but it refused to print properly and just made a bird nest.

Anything else to look at? Need to see pictures of my crappy box solution?

 

225 is low for ABS. Try a minimum of 230

 

Thanks Mike.

I've upped the temperature to 230°F and it seems to have helped. The print is better, but not perfect still. 230°F is near the limit of the stock hot end, right? I'm concerned that I shouldn't go any higher. Would slowing down the print speed help? I'm not sure what the speed is off the top of my head, whatever the Robo 3D setup guide told me to use, or Repetier Host default if the guide didn't specify.

Does using a higher/low infill percent affect the layer delamination?

 

235 is the max allowable temperature. You're fine up till that it's just once you get to the 250 range you start getting into a danger zone for the PTFE, but you can't do that unless you modded the firmware. Short version, 230 is fine.

So here's the thing with ABS. It has a thermal contraction that occurs on cooling. This is what causes warping and delamination. The more material you have down, the more contraction force s will occur. Thus, yes, more infill will likely lead to more delamination.

It could also be a result of the ambient air being too cool. As you get further away from the heated build plate the ambient air will drop and thus the difference in temperature between the applied layer and the cooled layer will be greater. This will lead to higher contraction tension and delamination.


You could throw a box or something on top of the printer to keep it warmer.

ABS is a tricky thing

 

Thanks Mike. I'll increase the temperature to 235, reduce infill to 33%, reduce print speed by 15-20% and go back to using my box. I also need to get some acetone and make some ABS juice to get my parts to stick better.

 

@Henry, it's 230°C not °F

 

Woops! I'd go back and edit it to eliminate confusion in case someone else comes in here looking for information, but I don't see an edit button.