Fan shroud for Devterm

looks nice!
But I think my CM4 will be in my hands wwaaayyyy earlier :laughing:

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I wondered why your shroud has these angles, now I realized they are due to the height differences because of the so-dimm slot. I opted for a simpler design thats possible because of 3d printing:

I will try a print and keep you updated :sunglasses:

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the hole is not perfectly centered, but big enough that it fits…

Please don‘t just print in PLA, that could get soft at those temperatures… I used PETG. I hope that is good enough.

Since I don’t see a way to attach a file here the code from openscad:

//numbers in mm

$fn = 50;

fan_w = 30.4;
fan_l = 30.4;
fan_h = 4.6;
fan_d = 21;

shroud_l = 25;
shroud_l1 = 3;
shroud_l2 = 11;
shroud_l3 = 3;
shroud_l4 = 8;

shroud_h1 = 4.6;
shroud_h2 = 7;
shroud_h3 = 1;
shroud_h4 = 2;
shroud_thickness = 1;

wall = 2;

translate([-fan_w-wall*2,0,0])fan_enclosure();
shroud();

module fan_enclosure(){

difference(){
    cube([fan_l+2*wall,fan_w+2*wall,fan_h+shroud_thickness]);                               //outer size
    translate([wall,wall,0])cube([fan_l+wall,fan_w,fan_h]);                                 //inner size
    translate([fan_l/2+wall,fan_w/2+wall,0])cylinder(d=fan_d, h=fan_h+shroud_thickness);    //fan hole
    translate([0,0,0])cube([wall*2,wall*2,fan_h+wall]);                                          //counter hole because of cable and easier mounting
    translate([0,fan_w,0])cube([wall*2,wall*2,fan_h+wall]);                                      //counter hole because of cable and easier mounting
}

}

module shroud(){

    difference(){
        
        union(){
            translate([0,0,fan_h-shroud_h1])cube([shroud_l1, fan_w+wall*2, shroud_h1+shroud_thickness]);                        //those 4 lines are to accomodate differnt heighs
            translate([shroud_l1,0,fan_h-shroud_h2])cube([shroud_l2, fan_w+wall*2, shroud_h2+shroud_thickness]);
            translate([shroud_l1+shroud_l2,0,fan_h-shroud_h3])cube([shroud_l3, fan_w+wall*2, shroud_h3+shroud_thickness]);
            translate([shroud_l1+shroud_l2+shroud_l3,0,fan_h-shroud_h4])cube([shroud_l4, fan_w+wall*2, shroud_h4+shroud_thickness]);
        }
        translate([0,wall,-fan_h])cube([shroud_l, fan_w, fan_h*2]);
        translate([shroud_l1,wall,-fan_h])cube([shroud_l2, fan_w+1, fan_h*2]); //because of the assymetric pci-e slot
    }

}

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Nice!

Another suggestion: I have removed the very thin tape behind the heatsink, then used a small piece (cpu size) of 3M thermally conductive double-sided tape (2mm thick, you can also use a thicker tape) to reconnect the cpu and the heatsink, which created a larger gap between the heatsink and core, and then… the overheating problem was solved!

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that would mean the adhesive tape is less heat conducive than your 3M…

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I’d be curious to see how this compares to the default adhesive on the heatsink. Maybe if someone else does this they can run a test with numbers, like the stuff posted here:

Given time I might even end up doing it myself and posting something. But I haven’t taken the time to actually build my devterm yet, so first things first! :slight_smile:

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That is VERY clean! A huge refinement on my 15 minute backyard job!
You’re 100% right re: my choices to do the angles based on the sodimm slot being a different height/angle.
You perfectly captured what I was going for, and absolutely nailed it!
Thanks! I’ll definitely be printing one myself!

Re: the thicker thermal compound conducting better than the tape, I remember my housemate telling me about quantum thermodynamics they were doing at uni relating to how something that seems like an insulator doing a better job at conducting. I’d be more keen to see the rest of the components touching the heat sink to pull more heat away.

However with a thicker compound comes even less clearance to the rear housing, and more hot air being localised and trapped. Ultimately a new rear housing design or modification needs to be done if we want to improve cooling.

I only encountered thermal throttling while trying to emulate GameCube/Wii on the “sixth gear”. Besides that though, nothing has really pushed my Devterm to the limit. Then again, I’ve only owned it for 3 days, so I’m sure to find something!

@adcockm ha! I was lucky I was in a huge model making bender! Otherwise it would have been stuck in my backlog too. If it’s any consolation, it’s actually a lot less work than the gameshell. You don’t even need to cut and sand the orange pegs down perfect for a slick build. They’re just retention pegs. Most of the mission critical parts are pre cut very nicely. :slight_smile:

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This is the test data using the “gear 6”:


and my heatsink :grinning:

I thought if I could get a larger heatsink like the M.2 SSD heatsink, it may be faster.

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This is very nice. I’ll give this a try when I get mine as well.

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Nice work! Completely un-related but I could not help but notice the rotary tool you were using looks to be based off a TS-100 form factor, I’ve never seen anything like it, also wondering what brand of pencil you were using, can always use more tools! :joy:

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I actually had to look up that TS100 tool! Hah, it looks potentially smaller? It has an auto shut off when it detects too much resistance. I use it for building model kits, and if stops me from melting my plastic too much. I just uses it to smooth off rounded cutout. It’s by a modelling company from China called dspiae. They make really nice tools. I’m a huge sucker for tools.

The pencil is a Rotring 800. Apparently rotring Germany got bought out by a Japanese company. So they released a modern ish iteration of the Rotring 600 drafting pencil, and named if the Rotring 800. It’s entirely metal, including the main internal shaft. Brass construction throughout.

It comes in a bunch of sizes and configurations. That one is a 2mm clutch pencil. I’ve also got it in 0.5mm with a capacitative stylus tip, 0.7 with a retractable brass barrel and a ball point pen variant.

I use it for drafting purposes, but honestly mainly use them for music annotation. Anyway here’s some more pics I took of them on my Insta, cos I don’t want to clog things up here. Login • Instagram

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The TS-100/TS-80 is fairly smaller but if you are looking for an open source soldering iron it is hard to be beat! Pine64 does make a similar open source iron called the “Pinecil”, I’ll give you a follow!

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I think if the fan delivers enough air the heatsink might be good enough, it is sometimes surprising how much a little bit of airflow helps!. .

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cooler is always better :laughing:

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Definitely. The problem mainly is thermal throttling that I’m experiencing when pushing the devterm to the limit.
I’m still getting throttling, although much later. I’m being stupid, and trying to emulate gamecube on it, just to prove it can. it does. just not in a very playable state. (yet)

The heatsink for my A04 was factory installed. The shroud was a little too long so I had to trim it down. If I get motivated I might edit your design to make it fit my A04 a little better. The trimmed version is fine, but I also messed up and got a bit of gold filament trapped in the print which annoys me so I want to print it again anyway.

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Those of you who have built a fan shroud for your devterm: how have your results been? Have you seen thermals decrease? Very interested in trying this out for myself if you have seen improvements!

Can we possibly get an STL for the shroud to print?

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PM me your email and I will send it to you, unfortunately it seems we can only attach pictures to posts here…

I’d recommend uploading it to a free file-sharing site (or Dropbox/Google Drive/etc.) and posting a link here. I’d like to get a copy too, but I imagine lots of DevTerm owners would. It’s the sort if thing that could go on the wiki too.

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