03-09-2021, 11:04 PM
Well I added a lid to cage in the fan but that didn't help as much as I hoped. First attempt was just a lid which had no effect so I added a wall so air only comes out one section, it did drop a little.
Results with cooling - Lid 3
Then I started wondering what temps do people get with heat sinks and went searching but couldn't really find much.
Officially Raspberry Pi says a heat sink isn't required.
https://www.raspberrypi.org/documentatio...ance-temps
Apparently the max temp is 185° F and the Pi starts to throttle down at 180° F to keep it from over heating although that link didn't mention it.
In my current conditions the fan did bring it down nearly 30° which isn't too bad. In a few months it'll be 80+ here so I can see what it gets to then.
One thing I forgot to mention is the lid stays 100% cool so it wouldn't warp.
The Pi 4 definitely runs hotter and is the bigger issue, I'm going to switch to it and see what I get.
Overall it's a balancing act for me, at this time I think I have to go with the internal fan and no heat sink for a few reasons. I did look around for taller headers but all seem to be 3.5mm or 8.5mm.
First I'm stuck printing cases for whatever I go with. Bottom line heat sink means tall case which could increase print time by up to an hour over the extra needed for the lid. I'm already always waiting on the printer. I feel the fan is needed as the lid can warp and that is definitely solved. Then packaging, the box I use just has enough height to stack the power bar and controller with space for padding above and below, any taller and I lose the top or bottom padding, as crazy as it might sound I would feel 10mm. The next standard size larger box means higher shipping and extra packing as it's more than I need.
I've used those header extensions on my old controller to stack an Arduino and Ethernet board on both sides of a board. The pins on extensions are thinner than standard header pins meaning poor contact. Many times I had to tell people to bend the tip of the pin so it would make contact plus an extra 40 points to corrode. I could use just the extension and solder the long legs in board and have it hover to the necessary height but the pins are flimsy so good chance plugging in the Pi will collapse the pins, if you aren't careful it's almost certain to happen. Either way it also means I need to cut 40 pins for every board I assemble as they will stick out of the board too much. Overall it's ugly and won't work, ok for one off but not production.
Going the fan route all it requires is redesigning the lid and only adds about 30 minutes printing time and does have definite benefits. Easy for anyone to install the fan and doesn't require any extra labor on my side which is what allows me to keep prices low. So yeah it's not as easy as it might seem. I'm kind of impressed the actual Pi temp dropped considering the fan moves little air, my original tests I didn't check it, when I realized that I was worried only the case temp dropped but it's a definite improvement.
Results with cooling - Lid 3
- Case temperature = 79.6° F
- Pi temperature = 96.6° F
Then I started wondering what temps do people get with heat sinks and went searching but couldn't really find much.
Officially Raspberry Pi says a heat sink isn't required.
https://www.raspberrypi.org/documentatio...ance-temps
Apparently the max temp is 185° F and the Pi starts to throttle down at 180° F to keep it from over heating although that link didn't mention it.
In my current conditions the fan did bring it down nearly 30° which isn't too bad. In a few months it'll be 80+ here so I can see what it gets to then.
One thing I forgot to mention is the lid stays 100% cool so it wouldn't warp.
The Pi 4 definitely runs hotter and is the bigger issue, I'm going to switch to it and see what I get.
Overall it's a balancing act for me, at this time I think I have to go with the internal fan and no heat sink for a few reasons. I did look around for taller headers but all seem to be 3.5mm or 8.5mm.
First I'm stuck printing cases for whatever I go with. Bottom line heat sink means tall case which could increase print time by up to an hour over the extra needed for the lid. I'm already always waiting on the printer. I feel the fan is needed as the lid can warp and that is definitely solved. Then packaging, the box I use just has enough height to stack the power bar and controller with space for padding above and below, any taller and I lose the top or bottom padding, as crazy as it might sound I would feel 10mm. The next standard size larger box means higher shipping and extra packing as it's more than I need.
I've used those header extensions on my old controller to stack an Arduino and Ethernet board on both sides of a board. The pins on extensions are thinner than standard header pins meaning poor contact. Many times I had to tell people to bend the tip of the pin so it would make contact plus an extra 40 points to corrode. I could use just the extension and solder the long legs in board and have it hover to the necessary height but the pins are flimsy so good chance plugging in the Pi will collapse the pins, if you aren't careful it's almost certain to happen. Either way it also means I need to cut 40 pins for every board I assemble as they will stick out of the board too much. Overall it's ugly and won't work, ok for one off but not production.
Going the fan route all it requires is redesigning the lid and only adds about 30 minutes printing time and does have definite benefits. Easy for anyone to install the fan and doesn't require any extra labor on my side which is what allows me to keep prices low. So yeah it's not as easy as it might seem. I'm kind of impressed the actual Pi temp dropped considering the fan moves little air, my original tests I didn't check it, when I realized that I was worried only the case temp dropped but it's a definite improvement.
