Looking for a good part cooling solution

Gandy

After upgrading my A5 with the Zesty Nimble Remote Direct Extruder, I am now working on exchanging the hotend with an all-metal E3D V6. The adapter design has now reached a state where I need to decide for a part cooling solution:

Obviously, there is no space to use any part cooling fan duct that fits to the original printhead. Also, while the Blowhard 3000 I am currently using, is a major improvement over the original fan duct, I am wondering if the cooling performance can still be improved. Here is a part cooling torture test I printed at 100% fan speed (I deliberately chose a PLA filament which I know is difficult to print if not cooled properly):

   

There is a slight anisotropy in the results, as can be expected, with acceptable results up to and including 40° overhangs. The overhang facing the front (towards smaller y) degrades heavily at 50°, whereas the one facing the back (towards larger y) starts to degrade at 60°. The central spire has some issues below a certain diameter when retracts are involved, but that relates less to the part cooler and more to why I want to change the hotend in the first place.

From looking at how the airflow interacts with a water surface, the main volume does not seem to hit the area under the nozzle. Instead, there a 3 distinct indents at ~7-10 mm from the nozzle. I'd hoped for a sweet-spot moving the z-axis, but there wasn't any, at least not where the nozzle didn't submerge..:

Searching for possible solutions, I came along the Petsfang which appears to focus the air flow directly under the nozzle:

Unfortunately and apart from the fact that it does not interfere with the hotend cooler, it does not fit on the x-carriage without sacrificing print volume (28mm in X, 8mm in Y and acceptable 14mm in Z):

The Petsfang is under a license that does not allow for derivative work, so I cannot simply modify it to avoid collisions. But there may be other fan duct designs with similar performance I could use.

So if you, despite the lengthy post, are still reading this and want to share your experience with your part cooling fan, please do so. If you feel like printing the torture test, I'd be very interested in pictures of your results.

aestrems

Hi, thank you for sharing this information.

The Petsfang is under a license that does not allow for derivative work, that's right and we have to respect the decision of the designer. However the Creative common license says this:
- NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material.

If I'm not wrong the license doesn't forbid you to modify the fan what is completely forbidden is distributing the modified file. 

I think the good think to do is to send an email to the designer of the Petsfang and talk to him about adapting his fun duct to the A5/A5S . I think is the best way  

Gandy

@aestrems thank you for stating this so strikingly, the importance of licences and honoring their terms can not be stressed enough. I did not really intend to make this discussion about licenses, but maybe I should have stated my intentions more clearly. Actually, I am aware of the fact that the restrictions mainly if not solely refer to distribution of the modified material. I could put some effort into modifiying the design to my liking and maybe learn something on the way, just to print and use it for myself.

On the other hand, taking benefits time and again of the amazing work others are willing to share every day, I am willing to offer something back by sharing my design if it actually works out. In this case, the carriage design will need some kind of part cooling solution. Whatever works for me should also be easily available to others. Most likely, I will decide on a license that allows someone who might find a better solution to also share. Not that I disapprove of or criticise other licenses like the one the Petsfang designer chose. He has his own good reasons and every right to do so and it's not for me or anyone else to question that. But again, that was not my intention in the first place. Actually, I did contact the designer to ask for a possible solution and as of yet I am waiting for a response. That request may not end up in a modified Petsfang that can actually be shared, but that would also be OK.

Currently, I am following a modular approach where different mounting brackets for the E3D V6 allow for different part cooling systems to be attached. There is already one bracket in the works that accepts a Petsfang with the least restrictions on available printing volume. Another bracket will fit a more slender cooling duct that does not impose unnecessary restrictions. If it should ever come to a specifically designed Petsfang, another bracket can be adapted, accordingly.

Still, that leaves the question on what your experiences with different part cooling designs are. I'll be happy to learn about them.