Using fan to help overhang and sharp corners?

Hi, I'm using Slic3r at the moment to generate the g-code but its cooling options are limited (getting better each version though).

I find that when I run my 40mm fan on full models come out much smoother/cleaner/tidier. But at the cost of strength. They break between the layers pretty easily. So I am wondering if there is a slicing tool that can turn the fan on for the moments when the print head is going around a sharp corner or doing overhang?

So while it is doing perimeter and infill the fan is off, and then during overhang and tight corners the fan turns on then back off when on the straight/long arc stuff... Possible?

Cheers,
Phiz

Not sure about that. it seems odd what you are talking about. do you want better prints or the fan feature for corners?

I had a similar problem with sharp (tighter than about 120 degrees) corners on my prints, they came out messy and sticking up too much. In the end the solution I found was to use 2 40mm fans, front and back of the head running all the time at about 60%, except on layer-0 when they're off, and raise the print temperature by 10-20C. Now I'm getting prints with neat, precise corners and no problems at all with layer adhesion.

With the fan running my parts are weak as they don't fuse between layers properly.

Without the fan 90degree corners and small arcs such as 3mm radius lift up.

What I want is to run the fan for short periods only while printing the perimeter of those small arcs and 90 degree angles.

is this on PLA or ABS? i'm curious about this too.


also, @ Azrael_UK, whats that fual fan configuration? double push or push pull?

@dragonfly Double-push, offset from each other slightly in the X-direction so they make a small vortex around the head instead of blowing directly at each other. I'm looking at upgrading to [www.thingiverse.com] this X-carriage soon though cause I'm not satisfied with the stability of the stock one, so that may change the fan arrangement.

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i had found this out a while back, but recently I bought a space heater to heat the piece as its printed. I noticed something amazing too, my kapton sheet had come unglued from my print surface, when I turned the hot air blower on the plastic began to behave like a soft heavy clay, the infill drooped instead of just staying flat and taught, and the sharp corners that would often raise without the hot air stayed at the level they were printed at. I cant control the temp output of the blower, but i may be able to mix in cool air to lower the overall output temperature.

ABS.