Another new one...

So, I’ve been playing with printing ABS lately. With the new 200W bed I’ve had no issues getting the bed up to 120 and staying there and I’ve never had any issues getting the hot end up to 230. Yesterday I was having troubles though, with edges lifting and perimeters not quite lining up against the center area. I watched carefully and noticed my extruder was wiggling during X axis movements. I killed the print and investigated to find that the clamp portion of the mount had stretched! It’s now a very loose fit, falling off with the slightest encouragement. The original mount (I assume made from PETG) I had had broken and I’d reprinted it with PLA. The only thing I have ATM for a theory is that the hotter hot end with fan blowing on it transferred enough heat to the mount for the PLA to soften. Anyone have other suggestions as to what the culprit could be?

I’m thinking I’m pretty close to ready to test a bowden/E3D combo out to allow more flow-through cooling on the throat…

I would guess the radiant heat from the bed is the issue. If you could insulate the mount bottom and any other exposed parts a bit im sure it would help.

If you are going to run your bed at 120C its going to soften pla parts. They start to get real soft at 60C, petg is around 80C I believe. Usually there is enough airflow to keep things cool enough. But 120C is really high does it stick for you at 90?

Another suggestion is ditch the abs and switch to petg, almost the same properties but prints with lower temps.

Do you have an old hair dryer that you don’t use anymore?
If yes, you can open it, inside there should be a sheet of fiberish insulating material that looks like carton. you can use this to protect your bracket against the radiant heat coming from your build plate+nozzle.
Aluminum tape could also do the trick, but less likely to work.

Wow, I print(when I print) abs with a 90C bed. I do print on painter’s tape though. Hotend at 210C. My printer is in an enclosure though, that really helps with abs, seems like the slightest breeze will screw it up.