You can get a knock-off of the sheet metal UM2 fan shroud on Aliexpress for pretty cheap. If you really want to print one, look for one that doesn't blow a lot of air directly on the nozzle, but evenly distributes airflow around it, pretty much like what @andywalter has described above.
Recommended Posts
andywalter 7
I have a UMO not UM2, but didn't find anything I much liked either. So I've 3D printed my own in ABS, in 2 bits. It uses the original single fan mounted in the original position. Aim is to get uniform air flow from all sides, trying to miss the tip of the nozzle but hit the hot plastic just below it!!!
The flattened torus is hollow, and couldn't have internal supports, so the model is sliced horizontally through the mid-plane of the torus. Then the sheared-hollow-cone bit is printed the other way up with full supports, and the tiny "cap" which is the bottom half of the torus is also printed upside-down with supports. Clean the supports out, Swiss-file the air-holes to clean them and Acetone-weld the bits together & it's ready to go.
I made the air holes to be angled-in, and the holes furthest from the main conical supply are slightly larger in diameter, as the air pressure will be slightly lower at the "far" end of the torus. It seems to work fine so far, ABS hasn't sagged or anything like that.
Top view. It's a bit tricky getting the nut onto thread through bottom-right hole. Next one I do will have a suitable cutaway-recess in the large sheared-cone section.
Edited by andywalteradd pics & improve layout of text + pics.
Link to post
Share on other sites