AirFlow in electronics compartment not optimal?

[Buurman]

Hi,

I am putting together my first Voron, where I am baffled about the design and how good things fit, I was surprised about the airflow/side skirts decisions.

With two fans PULLING air from the compartment (as advised) you should have a tunnel design to make it efficient. its designed to go from the left to right side of the printer.
Right now, the skirts next to the fans are OPEN, so are front skirts, even the skirts on the left could use narrowing to force the airflow over the electronics.
Airflow would try to find the path of least resistance, what means its just circulating around the fans almost.

My question is, has anyone else experimented with closing down the skirts everywhere but the left side, maybe even just the fan holes? (seen good mods)

https://www.printables.com/model/96714-voron-rm-front-rear-skirt-mod/files

I found these, but probably there are more, better ones.

[ahough]

I have the bottom on my printer and I started having issues with the PI getting too hot if the printer was left on after a print when the main compartment cooling fans would turn off. I also didn't want to leave the big compartment cooling fans running afterwards due to noise and power usage. So, I ended up designing some small fan brackets and attaching small 40mm fans that regulate the temperature of the main chip on my controller board and the PI. This also allows me to focus the main compartment fans primarily on the stepper driver cooling. The neat thing about this is it inspired me to add the chip temps to my console, so I could keep an eye on it.

I could keep my target chip temps higher than this, but I prefer to keep things nice and cool.

   

[claudermilk]

It really doesn't need to be optimized. While most people don't put the bottom on, that does help direct airflow a bit. Even after switching to 12V Noctua fans for the electronics bay (the 24V GDSTIME got really noisy), my CPUs on the Octopus & Pi stay in the mid-30s while they are running. But, I mounted mine pulling air in and blowing across the boards--I didn't even look at which way was recommended.

[SteveThatcher]

interesting, I never found anything that said what fan direction. I set things up to blow across the Pi, steppers, and controller. If the skirts had been closed up more, a fan direction blowing out would make sense, if the air inlet holes were in the right positions.

[Buurman]

True, I have been mistaken, it is mentioned in the manual what way the flow should go when srewing them on to the skirt, but I didnt notice that the skirt got fixed the other way around. So yes, they should blow inwards... and makes sense, feels like they make enough noise to cool all..  

I see a few noctua fans in my near future..... 

4 hours ago, SteveThatcher said:

interesting, I never found anything that said what fan direction. I set things up to blow across the Pi, steppers, and controller. If the skirts had been closed up more, a fan direction blowing out would make sense, if the air inlet holes were in the right positions.

 

[SteveThatcher]

21 minutes ago, Buurman said:

True, I have been mistaken, it is mentioned in the manual what way the flow should go when srewing them on to the skirt, but I didnt notice that the skirt got fixed the other way around. So yes, they should blow inwards... and makes sense, feels like they make enough noise to cool all..  

I see a few noctua fans in my near future..... 

understand... front, back, left, right, forwards, backwards, 180 degrees and 0 degrees... they did turn things around quite a bit

[porkbrains]

Noctua fans are quiet but have reduced CFMs. If you can duct them directly to the components I suppose they would cool well enough. Proceed with caution. 

[Buurman]

7 hours ago, porkbrains said:

Noctua fans are quiet but have reduced CFMs. If you can duct them directly to the components I suppose they would cool well enough. Proceed with caution. 

Thanks, I know, silent but slow, currently running the ones I have on 50% speed and its a good compromise on sound and air movement. (for now)

[claudermilk]

Looking at my Fluidd page right now. Running a print job and Octopus is at ~39C, Pi is at ~37-39C. This is with two 12V Noctuas running at 100%. It won't climb beyond that. The Pi CPU is rated to 85C before it starts throttling. Quick checks on the Octopus chips, the STM32F446 looks like it's rated to 85C or 105C. The 2209's appear to have a significantly higher tolerance. So short story long: the Noctuas seem plenty sufficient for the electronics bay cooling with the open skirts (and bottom installed--but that probably doesn't really matter).

[porkbrains]

That’s really good to know. Quieter fans would be awesome. Thanks for the info!

[claudermilk]

These are the specific ones I got: https://smile.amazon.com/gp/product/B009NQMESS

Be sure to remember to change the voltage jumper to 12V. They will run at 24V. For a while. And they won't be happy doing it... 

[Buurman]

7 hours ago, ahough said:

I have the bottom on my printer and I started having issues with the PI getting too hot if the printer was left on after a print when the main compartment cooling fans would turn off. I also didn't want to leave the big compartment cooling fans running afterwards due to noise and power usage. So, I ended up designing some small fan brackets and attaching small 40mm fans that regulate the temperature of the main chip on my controller board and the PI. This also allows me to focus the main compartment fans primarily on the stepper driver cooling. The neat thing about this is it inspired me to add the chip temps to my console, so I could keep an eye on it.

I could keep my target chip temps higher than this, but I prefer to keep things nice and cool.

   

I installed this baby, its not expensive, totally silent, and keeps my PI als around 35 degrees. I did put it on 3.3V instead of 5V to make it extra silent, but I cant hear it at all, so 5V is probably also ok.

[ahough]

14 minutes ago, Buurman said:

I installed this baby, its not expensive, totally silent, and keeps my PI als around 35 degrees. I did put it on 3.3V instead of 5V to make it extra silent, but I cant hear it at all, so 5V is probably also ok.

That looks great!

You're wiring is so clean. It's making me want to go back and clean mine up.