ABS Print and auto cooling option (Slic3r)
Hi,
so sorry for my english, i'm french..
Many people say "don't use fan when you print with ABS...".
So what do you think about "Auto cooling option" in slic3r with ABS filament ?
When i try to print peace in ABS, my peace are better when i turn on the auto cooling option...for peace who have hole for example..
So what is the best ? use or not use auto cooling for ABS printing ?
Thank you for your answer.
Re: ABS Print and auto cooling option (Slic3r)
In an Ideal situation you want Zero Cooling fan when using ABS or Nylon, however this is impossible in the real world.
You need the fan to lock in the ABS and Nylon dimension-ally so it does not continue to shrink when it cools naturally.
the problem with the Cooling is it causes the material to not fully bond layer to layer so you get a part that is weaker then it could be without the fan.
the best solution is to just use enough fan to get the detail you need and as much strength as you can get with that level of detail.
it means doing multiple tests searching for just the right combination of Fan the lowest you can find to complete the print.
however the best combination between detail and strength will not be very strong. this may result in having to redesign and beef up your design as much as possible to have some slight compensation of strength.
using lots of fan: Very nice ABS prints will be Brittle like glass. very nice Nylon prints will de-laminate by hand or snap off little details as it could not fully bond to the layer below.
So in short use very very little fan where possible. Autocool gives you some more flexibility in additional cooling since you can vary it with layer time the shorter the layer the more fan. you can also Delay a level and force the printer to wait a specific time before continuing that is above just slowing the machine down when printing. jut understand in the areas where the fan is working the most the ABS or Nylon will be even weaker then it should be.
an unintended side effect of autocool will be areas of the part will be stronger and areas weaker so you can have 5 layers that are very strong and 2 layers very weak and then 4 layers very strong which will make the part snap right at the weak layers.
leaving the fan on constant low weakens the part but seems to keep the strength more consistent then autocooling
there are situations where you must Hand code the Gcode to set aside a section of the layer where the fan must be 100% turned off. and then turned back on. this is a feature almost no slicers have at the moment, and you will have to manually program it.
there is additional post print processes with ABS and acetone that can address some finishing issues and some strength.
I hope this helps
dan
“One does not simply use a picture as signature on Prusa forumsâ€
Re: ABS Print and auto cooling option (Slic3r)
I recently found out that I have had to use auto cooling with small ABS parts. Because the next layer is coming along so quickly, its not solid enough to support another layer. So auto cooling is used to start up when the layers are so small that they need help cooling down to become more solidified.
You can set up the auto cooling to come on only when it takes so many seconds to the next layer. This way its off normally until you get to the small layers of the print.