Overhang solutions

Overhangs are driving me crazy. I have never been able to reliably print overhangs. I use a .35mm J-head nozzle printing PLA only. I have a 40mm fan that blows at the part and nozzle. If i use two fans my hot end cant stay hot enough to print reliably. Ive tried printing support with two different slicers and while it can be done it causes more problems than it solves.

What is the real solution to stop the overhangs from curling up?
Is it more fans? Ive noticed some people using a ring style nozzle that goes around the print nozzle which i assume keeps the cool air away off of the nozzle.
Is it support material?
Is it needing to print at rediculously slow speeds on overhangs?
Or is it all of the aove?

more resolution in z axis helps, also keeping overhangs to less than 45deg helps. increasing flow rate may help as well, because the side walls can be thick enough to support overhangs.

jamesdanielv Wrote:
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> more resolution in z axis helps, also keeping
> overhangs to less than 45deg helps. increasing
> flow rate may help as well, because the side walls
> can be thick enough to support overhangs.

At the same time you want to check your flow rate is bang on for the extrusion width you are expecting - otherwise too much plastic can go down making the problem worse!

A ducted fan works much better than just a fan in my experience. However 40mm was too small and I now use a 60mm fan to get a decent airflow. You should insulate the sides of the metal block of your jhead. Wrapping a couple of mm of kapton tape around it will do the trick!

I have a bunch of ducted fans for RC jets laying around. Some of my 40mm spool up to 50K Rpm and an exhaust speed around 100mph+ , maybe that would do the trick. LOL.