First off, I'm a big fan of what Vorta has been doing on his thread - if you haven't checked it out, definitely go there and check it out:
https://bitcointalksearch.org/topic/antminer-s5-3d-printed-mods-1072176I've been experimenting a fair bit with different case designs as well - in particular trying to find the best balance of cooling + sound + ease of build. As Vorta mentions, the thermal sensor on the blades is really a poor design - it doesn't really give you a good sense of what the board is actually doing, as I've I've seen it report 70c when it reality it was 90c+. I have a thermal camera (BTW, you can mod the E4 to have all the features of the E8, awesome!) that I've been using to analyse the heat dissipation and what is actual happening to the boards as I change things around - and try to use things less subjective, like anemometer to measure actual airflow, etc.
It's important to note on the thermal side of things it's a bit tricky measuring it - because things like acrylic are not thermally transparent, so they need to be removed in order to measure temperatures. At the same time, this affects the airflow, so in general I try to let it run for a couple minutes assembled, then pop off the side or whatever and image it so I get something that's closer to what reality is.
The first thing I did was replace the sides - personally I like the look of the circuit boards, so transparent acrylic works well for it in this case. I was also bored and decided to etch a BTC logo in it to be fancy:
I went through several design iterations, but ended up with this as the best general configuration - the sides are 2mm acrylic and the top and bottom are 5.6mm, but only because I used up all my 2mm and only had 5.6mm left. I think 2mm all around is what I'll use for my finished version. I also took the hint from Vorta's on ducting, and put a 5.6mm spacer between the fan and the enclosure - this actually made a big difference no matter what you're doing, so if you're looking for a super simple mod to do - do this. Here's the assembled verison:
It's worth pointing out the only the sides and bottom are screwed in - the top just rests on the PCB and sides. I found this to be the most convenient, and the cables and everything else hold it in place really well, so there really isn't a big need for anything else. You can see here how it attaches to the bottom:
Vorta filled in the bottom area with his design - which I think is technically better, but most of the fins on the bottom of the heatsink on my S5's look like a dogs lunch, so this works in all situations, and gets the bulk of the gains. You can see here a closeup on the top, and how it's edged around the Beaglebone:
In some of my earlier designs, I basically screwed into the top much like I did on the bottom of the heatsink, and then made my own mounting adapter for the Beaglebone - but this didn't make any difference in my measured results, and was actually a huge PIA to install - whereas this one just drops on and you're good to go.
Now, the only thing better than not generating heat is getting it the F away from whatever is making it, so ducting is also a big consideration for me - here was one of my first experiments with this design and a 4" duct:
Unfortunately, a 4" duct doesn't allow a large enough volume of air through, so it hurts the thermal performance too much for my tastes. I'm in the process of changing the flange that connects to the case, and moving up to the larger 6" ducts common to HVAC. I know I could have gone to 5", but in the US at least they are hard to find at Lowes or Home Depot, so better to have too much air volume than too little.
Once I was happy with the general design, I started playing with fan configurations - push, push/pull, and just pull. While I love the performance of the stock fan, I don't like the sound level - I've literally bought every 120mm fan that Amazon has to offer, and I've settled on this one:
http://amzn.to/1S6nDAVI've probably bought about 50+ in the past few weeks, so they're probably wondering what's going on!
It doesn't have nearly the performance that the stock fan does, but it has the best balance of the ones I've used. One downside is that it's not PWM controlled, but it's fixed speed of around 3k is more than acceptable for my purposes, since all my S5's ever do is spin up to full speed anyway - and personally I'd rather have the fan fully working the whole time anyway. Back to the case, without the enclosure, push is definitely the way to go - with there being a slight advantage to push/pull, but generally not worth the extra cost IMO. But, with the enclosure, pull works significantly better, and push/pull gains even less than the non-enclosure situation. Now, keep in mind, I'm basing this off my thermal readings of the PCB, not the temp reported - although in general they tell the same story. So here's one of them in action:
I think I may do a couple more minor tweaks, but I'm pretty happy with this design, and I'm more than likely going to do a big batch of them so I can upgrade all my existing cases. I wish I had one of the new S5's with the heatsinks on the side to test with, but even though I've bought a ton of S5's in the last month, I haven't been able to score one with them.
If anyone has any suggestions or ideas, I'd love to hear them... Since I'm in the mode of still tweaking it, now's the time!
And if there's enough interest, then I may make them for other people when I do my big batch - one nice thing is it's super easy to do, you can install it in under 5 mins and it's good to go.