Playing with the air nozzle design  

Re: Playing with the air nozzle design

I used the PC from ICE too and i got realy good results with this settings, attached in this post.
But i got an enclosure and i use gluestick.

Try it. maybe it will work for you too.

make sure, you use the print- and printersettings attached in this profile too.

Re: Playing with the air nozzle design

In the end, I got a good result with HK PC by using the stock Polymaker PC template modified with the following: 270/275 nozzle, 100/115 bed, auto cooling on, fan speed 0-30, bridges 30%, enable fan if < 20s, slow down if < 40s *and* 3 perimeters.

Here's the nozzle after a little hair dryer / wire brush cleanup:

To be on topic: haven't done any scientific performance tests, but cooling seems to be improved on the "seat of the pants"-o-meter. Thank you, @RHDreambox ! 🙂

Re: Playing with the air nozzle design

Thanks for design. I tried it hoping it will solve my problem with thermal runaway with R3 design. However this cools even more then Prusa original. When the fan starts on 100% after first layer, temperature on heater block goes down from 210 to 190 in some 10 seconds and print failed with thermal runaway. With this design I do not make it in time to reduce fan speed on LCD. So very good cooling, but not with MK2.5 R3 extruder 🙁
Magnetic heated bet is perfect, but printer reliability went down rapidly, bad decision with upgrade.

Re: Playing with the air nozzle design

When the fan starts on 100% after first layer, temperature on heater block goes down from 210 to 190 in some 10 seconds and print failed with thermal runaway.

i would get some e3d silicon socks to avoid that. that insulates the heater block.

Re: Playing with the air nozzle design

With this design I do not make it in time to reduce fan speed on LCD.

This sounds like something that can easily be fixed in software. Did you contact the developers?

Re: Playing with the air nozzle design

i am solving this issue for couple of months. Finally also tried Prusa chat. It seems that the heater is not givining what it should give. And there for it reacts not fast enough for the fan start. So every attempt for better cooling makes it worse. I meassured just 9.1V on the heater (have 12V version). That might be the reason. So will try to replace the heater first, maybe it could help and is quite easy. Then I will stay with this design, sure 🙂

Re: Playing with the air nozzle design

Hi RHDreambox

How far does your simulation program go? I found an intake funnel on thingiverse that claims to enhance airflow
https://www.thingiverse.com/thing:2718992

I printed it but it does not fit on 45 degrees mounted fan. So I really wonder if the concept does actually work. Especially while moving X. But IF that works it would be interesting to design a smaller version that fits on 45 degrees:-)

Best regards!

Re: Playing with the air nozzle design

Nozzle RHD Revision C is now uploaded at Thingiverse
https://www.thingiverse.com/thing:3249344

The deformation of the tip of the nozzle left side is a little strange. Could it be due to heat radiation from the thermal cartridge cable end, or is the extruder fan that sucks warm air over the tip from the hotend?

Hi RHDreambox,

I am currently considering installing the bear extruder on my MK3. Yet it is your nozzle that makes me hesitant. I heard from Gregsaun (author of the bear mod) that on that extruder the PINDA is one millimeter closer to the front (in y direction) as on the stock extruder. And of course, its philosophy is to have the center of gravity as close to X axis as possible. And to better protect the fans bearings by having it vertical. So I would like to ask if you have thought about doing a 90 degree version of your awesome nozzle and also check distance to PINDA in cad regarding bear compatibility 🙂

Would be awesome:-) What do you think?

Best regards

Re: Playing with the air nozzle design

How far does your simulation program go? I found an intake funnel on thingiverse that claims to enhance airflow
https://www.thingiverse.com/thing:2718992

I have tested this, but I could not see that there was any capacity increase of airflow. Perhaps the flow is too small, or I do not manage the simulation program correctly 😳 😮

So I would like to ask if you have thought about doing a 90 degree version of your awesome nozzle and also check distance to PINDA in cad regarding bear compatibility.

I have made many different nozzles now (one box full) but not something for a vertically mounted fan. But Christmas is long, so maybe I'll get along with that too 😀
Right now, I'm testing different solutions where I've removed the centered outlets. I have a theory that the centered outlets counteracts the airflow from the outlets in the sides.

Regarding the location of PINDA on the "bear", I think it's enough that I do a little less radius on the nozzle to avoid collision.

Re: Playing with the air nozzle design

Regarding the location of PINDA on the "bear", I think it's enough that I do a little less radius on the nozzle to avoid collision.

That would be awesome!

If you need CAD files. The bear extruder is completely open source

https://github.com/gregsaun/bear_extruder_and_x_axis

Re: Playing with the air nozzle design

Regarding the location of PINDA on the "bear", I think it's enough that I do a little less radius on the nozzle to avoid collision.

Very good news! I am the Bear developer so I would be very happy to help you if needed. In case of, you can get my source file (Fusion 360) on my GitHub here : https://github.com/gregsaun/bear_extruder_and_x_axis/tree/master/src .

Out of the bear question, I have some questions and proposals (at least for testing) :

I also take this opportunity to thank you for all the hard work on this shroud as well as on the other parts of the printer!

Re: Playing with the air nozzle design

Very good news! I am the Bear developer so I would be very happy to help you if needed. In case of, you can get my source file (Fusion 360) on my GitHub here : https://github.com/gregsaun/bear_extrud ... master/src .

I downloaded your files to convert them to STEP, but I only managed to open some of them. On the others I got the error message (New design cannot be created from a local file containing external references).
I downloaded Fusion 360 to convert your files, so maybe I was wrong because I'm not used to that program.

But I managed to collect STL files from different places so that I got together the most important parts.
And, I do not think the new PINDA placement will be a problem. I also assume you want the fan where it was previously located.
I promise nothing, but I will take o look at a suitable nozzle.

Re: Playing with the air nozzle design

Very good news! I am the Bear developer so I would be very happy to help you if needed. In case of, you can get my source file (Fusion 360) on my GitHub here : https://github.com/gregsaun/bear_extrud ... master/src .

I downloaded your files to convert them to STEP, but I only managed to open some of them. On the others I got the error message (New design cannot be created from a local file containing external references).
I downloaded Fusion 360 to convert your files, so maybe I was wrong because I'm not used to that program.

But I managed to collect STL files from different places so that I got together the most important parts.
And, I do not think the new PINDA placement will be a problem. I also assume you want the fan where it was previously located.
I promise nothing, but I will take o look at a suitable nozzle.

Mmmmh I'll give a check, project export with Fusion is not the most stable feature... I think you will only need extruder body and cover or do you need something more? Stepper?

Pinda is 1mm more in front on my extruder (but the X carriage is 1mm closer to rods)

Re: Playing with the air nozzle design

Very good news! I am the Bear developer so I would be very happy to help you if needed. In case of, you can get my source file (Fusion 360) on my GitHub here : https://github.com/gregsaun/bear_extrud ... master/src .

I downloaded your files to convert them to STEP, but I only managed to open some of them. On the others I got the error message (New design cannot be created from a local file containing external references).
I downloaded Fusion 360 to convert your files, so maybe I was wrong because I'm not used to that program.

But I managed to collect STL files from different places so that I got together the most important parts.
And, I do not think the new PINDA placement will be a problem. I also assume you want the fan where it was previously located.
I promise nothing, but I will take o look at a suitable nozzle.

Here are the step files, let me know if you need more 😉

ps: I could not replicate your issue with fusion 360

Thank you very much!

Re: Playing with the air nozzle design

I was wondering,
what is the reason for keeping the air outlets at quite some distance away from the heater-block?

When I got the measurements right, the side-outlets are 5 mm away from the heaterblock, so why not go down to 3 mm?

Re: Playing with the air nozzle design

Printing with a smaller distance between the fan duct and the heater block will result in a deformed fan duct when printing at high temperature with low part cooling fan settings, even with a PC fanduct.

Re: Playing with the air nozzle design

Would a silicone sock improve this?

Re: Playing with the air nozzle design

A silicone sock would help, but only as long as it's intact. I do not want to usw any parts that can simply fall off during printing.

Re: Playing with the air nozzle design

the socks are consumable item when you take them off to give your heater block and nozzle a good brushing with your soft brass brush take the chance to turn them inside out and crack off any cooked plastic and inspect them for signs of deterioration if they don't return to their proper shape after cleaning then replace them that is why they are sold in pacs of 3

Re: Playing with the air nozzle design

Something more to think about if you want to improve your printer.

https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/nozzle-droping-not-a-heat-problem--t26844.html
and
https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/the-extruder-injector-duct-does-not-work-as-intend-t26832.html