How much air flow is needed for PLA? Hey everyone. I have a Makerfarm Prusa i3 with a hexagon hot end, which requires a fan blowing on it at all times. I had an interesting idea to make a fan shroud that would divert some air from the hot end, over to the extruder. A large portion of the fan is blocked by the extruder mounts anyway, so if I space the fan away and free that up, I should be able to take some flow over to the nozzle without effecting the hot end cooling too much. I'm just worried that it would be enough cooling for the PLA. So how much air flow is actually required? Is having a dedicated fan really necessary? Thanks! https://reprap.org/forum/read.php?1,454063,454063#msg-454063 Mon, 14 Sep 2026 23:54:14 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,454063,454282#msg-454282 Re: How much air flow is needed for PLA? https://reprap.org/forum/read.php?1,454063,454282#msg-454282 LoboCNC General Mon, 12 Jan 2015 14:39:12 -0500 https://reprap.org/forum/read.php?1,454063,454222#msg-454222 Re: How much air flow is needed for PLA? https://reprap.org/forum/read.php?1,454063,454222#msg-454222 This hel0s the bed adhesion. Or you may need more fan speed for smaller prints to cool them quicker.

But you need a constant fan for the hexagon to keep the cool end cool. On all the time the hot end is powered.

So i cant see how a single fan shared between keeping the hexagon cool and the variable fan for cooling the print could possibly work.

Ive got the hexagon hot end myself on my prusa i2 with a slim tiny 12v fan on constantly and a seperate variable fan, controlled by
marlin on ramps, for ninjaflex and pla. I mainly print abs but without a fan.
It works very well but does need the cooling fan on the cooling fins constantly.
It was quite a bit of work fitting that lot into a custom carriage for my prusa i2. Not a lot of room between the smooth rods.
I should imagine you have more room on the i3 so you wont save anything by combining the cooling of the hexagon and print with the same fan.

Gordon]]> gordonendersby General Mon, 12 Jan 2015 12:40:29 -0500 https://reprap.org/forum/read.php?1,454063,454105#msg-454105 Re: How much air flow is needed for PLA? https://reprap.org/forum/read.php?1,454063,454105#msg-454105
Quote
Traumflug
Well, give it a try and tell us. Very early extruders worked without any fan, so I guess it's a matter of patience. With insufficient cooling you have to print slower to allow the heat going to ambient. Where "insufficient" starts ... who knows without trying it?

Yeah I've been printing without a fan for a while and I see the need for it. I'm working on a design but I'm just afraid it won't be adequate.]]> nope_bye General Mon, 12 Jan 2015 08:00:09 -0500 https://reprap.org/forum/read.php?1,454063,454068#msg-454068 Re: How much air flow is needed for PLA? https://reprap.org/forum/read.php?1,454063,454068#msg-454068 Traumflug General Mon, 12 Jan 2015 06:28:45 -0500 https://reprap.org/forum/read.php?1,454063,454063#msg-454063 How much air flow is needed for PLA? https://reprap.org/forum/read.php?1,454063,454063#msg-454063
I had an interesting idea to make a fan shroud that would divert some air from the hot end, over to the extruder. A large portion of the fan is blocked by the extruder mounts anyway, so if I space the fan away and free that up, I should be able to take some flow over to the nozzle without effecting the hot end cooling too much.

I'm just worried that it would be enough cooling for the PLA. So how much air flow is actually required? Is having a dedicated fan really necessary?

Thanks!]]> nope_bye General Mon, 12 Jan 2015 05:56:06 -0500