Hotend fan shroud

Projects & Prints
1

Not a very glamurous project, more of an experiment, really.

Someone on these forums once asked if it would make sense to print FDM printer hotend and extruder parts on a Form1. Obviously, for any structural parts, the answer is no (at least with regular, non-tough resins), due to brittleness. And resin parts aren’t very suitable for high temperatures either, because they tend to make methacrylate crack.

However, out of curiosity, i decided to give printing a hotend fan shroud (duct) a try, just to see how well it works.

I’ve been having serious reliability troubles with a particular hotend (that i won’t name out of decency, until i get a response from its makers) and a printed fan shroud they’ve sent along with the hotend. Even their updated shroud design they’ve emailed me sucked pretty badly (no, not “sucked air”, that would’ve been a good thing). So i’ve decided to design my own and give it a shot.

https://dl.dropboxusercontent.com/u/1702513/Photo%2009-09-15%2023%2030%2055.jpg

Ignore the fan orientation, it’s wrong in this photo :smile::

https://dl.dropboxusercontent.com/u/1702513/Photo%2010-09-15%2016%2021%2055.jpg

In action:

https://dl.dropboxusercontent.com/u/1702513/Photo%2010-09-15%2016%2029%2005%201.jpg

https://dl.dropboxusercontent.com/u/1702513/Photo%2010-09-15%2016%2030%2009.jpg

3 Likes
2

Observations so far - heat makes the resin expand slightly, but plastically, not elastically.
I.e. once it heats up, the grip on the radiator fins loosens and remains loose.

1 Like
3

So far so good.
Apart from the expansion / loosening, no adverse effects from the heat.

One thing you need to make sure of when printing objects that are going to be exposed to high temperatures - give them PLENTY of time to cure. Apparently, the themal expansion is partly dependent on the state of resin. If the object is not completely cured, or not uniformly cured, it will deform (warp) badly when heated.

4

Fourth iteration (the blue FDM one was 0th) curing:

https://dl.dropboxusercontent.com/u/1702513/Photo%2013-09-15%2017%2035%2019%201.jpg

1 Like