Fan shroud upgrade?  

Yes, but...

I have found a shroud that provides better cooling around the back (IMO) but I'm still on the original R2 extruder & hotend design.

Improved part cooling fan duct.

I have found this gives a small but quite worthwhile improvement particularly on bridging and on back side overhangs:
https://www.thingiverse.com/thing:4106196

I have it printed in a cellulose lactide or PLA/PHB material.  In my case Extrudr Greentec Pro Carbon, but normal Extrudr Greentec Pro or Fillamentum NonOilen will work just as well; both have a HDT >=110°C

I also tried the Improved Part Cooling Fan Duct

I did print and switch to the above mentioned improved part cooling duct but switched back to the standard one after a couple of weeks. Initially after first installing it, I thought that it was better but after more detailed testing, I concluded that the results were similar to the standard fan running at about 75%. It also meant that I could not rely on the various standard Prusa Slicer profiles for different filaments so confidently. There may have been a small improvement in cooling behind the nozzle and the nozzle visibility during printing was great though.

@xanthe

Interesting, but it looks like there's no Mk3S+/R6 compatible version of it, and no step or f3d files.

Concur

It would be good with the designer made one.  

Posted by: @fuchsr

@xanthe

Interesting, but it looks like there's no Mk3S+/R6 compatible version of it, and no step or f3d files.

RE: Fan shroud upgrade?

This is the one that I tried on my Mk3S+:

https://www.prusaprinters.org/prints/62523-delta-p-fan-duct-v2-r2-for-mk3s-extruder

@brad-2

Is the Delta P the one you were referring to in your previous post as basically delivering 75% of the original shroud? I thought you were referring to the one that @xanthe mentioned in the post before that. 

While I'm always intrigued by the ingenuity of these designs I can't help but wonder if it actually translates into consistent, repeatable performance gains -- ideally without the need to maintain separate profiles or if I don't want to switch every machine over. 

Sorry...

I missed that you were using a Mk3S+.

Yes I installed the Delta P fan duct and after a while concluded that the stock duct had actually provided more cooling (at least for my models) so I reverted. Let me know if you need more information about how I came to this conclusion.

Posted by: @fuchsr

@brad-2

Is the Delta P the one you were referring to in your previous post as basically delivering 75% of the original shroud? I thought you were referring to the one that @xanthe mentioned in the post before that. 

While I'm always intrigued by the ingenuity of these designs I can't help but wonder if it actually translates into consistent, repeatable performance gains -- ideally without the need to maintain separate profiles or if I don't want to switch every machine over. 

Thanks guys. I think at this point I just go with the stock shroud. I have occasionally seen some issues with severe overhangs but it's not common for the models I'm printing.