print fan mod to get rid of the lousy stock fan  

RE:

There is nothing specialised or custom about the fan.  It is a standard radial blower fan that can be purchased pretty much anywhere. 

A radial blower fan and is perfectly suited for the role it was selected to do. That is, to move high volumes of high speed air from a very small and light package.

The design is quite well engineered and is why it has been this way for many years without issue.

I have literally done many hundreds of nozzles changes without incident. I am sure others will attest the same.

If you are breaking it as a result of doing nozzle changes,  you are doing it wrong and should watch some YouTube videos on how to do it correctly. 

RE:

thanks for the insights.

i do not know enough about radial fan standards and assumed, that one was design for prusas printers. and therefore you would need to build a workaround if you do not find an alternative model. but if this is a standard design, then this is good news. i will ddo better research then for getting a replacement in the future. so far i found not so many alternatives or only some from the same quality. and the soldering is poorly made, it breaks too easily and when you take a closer look on the connections it makes sense. so i was hoping for some better quality fans and happily pay more for it.

i know hot to change a nozzle, i followed the manual, there are  reasons why the fan still can fall and stress the cable connections. the fan itself has bad reviews in the prusa shop. probably for good reasons - even if you substract the unreasonable complaints or people who just don't know what they are doing.

RE:

It's poor form to call the fan 'lousy' and to carry on about and then later admit that you don't really know anything about it.

Given you hold the heater block with one hand and tighten the nozzle with the other; I fail to understand how you are braking the fan on a nozzle change?

You don't remove the fan to change the nozzle.

RE:

it's poor form to claim  i am doing the nozzle change wrong and recommend me youtube videos while you seemingly don't know the official tutorial about it, which i followed - and therefore removed the fan.

maybe this stupid judgement thing can end and we can focus on the topic itself again 😉

i call the fan (model) lousy because of it's poor weldering quality on the connection, which will break sooner or later if moved to often or put under constraint. and following the offical guide you need to handle and move the fan and when you put it not well enough between the belts, i can fall down.
the housing design is, what i have no knowledge about and so i was wondering, if there are other radial fans with other housings that can be made compatible. that's it.

more people face the same problem as it seems (review on the fan in prusa shop, some reddit posts), other have problems with fan noise even after shorter usage - even more postings on reddit about that. one person mentioned, that fans in angled positions are prone to rattle or get bearing trouble.

i don't know, if there are better models with better welding - maybe not. but you said it and also i started wondering about the fan removal after some nozzle changes - it does not seem to be nesccessary. so maybe i am just good with leaving the fan, where it is. if i am creative and motivated enough i can still start to build a mod - bringing the fan in a vertical position and guide the air differently. or try out, if an axial fan model with similar specs would work, if you build an air guiding housing behind it. let's see...

RE: print fan mod to get rid of the lousy stock fan

I have a custom fan shroud on my printer and I don't find changing the nozzle is hard.  I have the correct size metric wrench and socket to hold the print head and turn the nozzle.  The right tools for the job make a bid difference.

As with anything today, you can get a bad batch of equipment that is mass produced.  I have had new fans create headaches and sound like jet engines right out of the box and other fans that are a decade old with no noise.

A faulty thermistor has been my biggest headache of 3D printing.

RE:

i am not blaming prusa here, they don't build the fan. maybe there is too much variation in quality or the fine is just fine, if you never touch it again after mounting it. but if you follow the official guide... see above. so, for the guide you could argue with prusa and i think, i leave my feedback on this chapter, so they can adjust it. if they agree.

changing the nozzle is not hard, without touching the fan it's actually easy, yes.