Cuzza's Sega SC-3000H Nano-ITX Mod

[Cuzza]

Great mod Cuzza.

Just read through the whole topic and it really inspired me to try something similar

Good for you. What do you have in mind? I hope you will keep a log thread to share your experiences.

 

[Lazzer408]

Pardon my paintbrish skills, but if you cut out the middle you could make your fin layout work. That's the only way I can see you getting away with optimizing that design.

On another note. Look into removing the fan's housing and just leave the motor base and screw it to the heatsink. Everywhere you see plastic around the fan, you would have fins.

EDIT - Like I did in the second pic. This will take all night but you get the idea and can see the fin area you will gain. That's how I would have done my heatsink if I had a mill handy. Notching mine out like I did was easy on the bandsaw.

 

[bigsharn]

I love it, that working keyboard must have been a nightmare

 

[Cuzza]

Lazzer, great idea removing the fan housing, I never thought of that! i still want it to be able to exhaust out the sides so i'll make that work. sketchup is going to be busy.

@bigsharn, the keyboard was only hard in the planning stage. it took a lot of effort to work out, but was easy enough to execute. glad you like it!

 

[Lazzer408]

Lazzer, great idea removing the fan housing, I never thought of that! i still want it to be able to exhaust out the sides so i'll make that work.

The edited picture I posted was just to show the fin area gained. Without your build in hand it's hard to suggest anything optimal. You get the idea and that's what matters. I actually just found this thread yesterday. lol Now I know wtf you were talking about before. Looking good. Good luck with it.

 

[Cuzza]

Custom Sega Heatsink mkII

Redrawn from scratch. This one took me about 6 hours, lol. My sketchup skills have slipped lately! And the PNG didn't render very well this time, not sure what's going on there.

Anyway, Lazzer I took your idea on board and this would be much more effective. If you can't work it out the airflow goes like this

You have to realise that in the case there is no space (about 1-2mm) above the heatsink. So most of the air will go where the fins direct it. There is maybe 4-5mm above the fan, not ideal but should give enough air for it to be effective, even at low (silent) fan speeds.

You like?

 

[Lazzer408]

http://img.techpowerup.org/091031/heatsink multi.png


Redrawn from scratch. This one took me about 6 hours, lol. My sketchup skills have slipped lately! And the PNG didn't render very well this time, not sure what's going on there.

Anyway, Lazzer I took your idea on board and this would be much more effective. If you can't work it out the airflow goes like this

http://img.techpowerup.org/091031/heatsink airflow.png

You have to realise that in the case there is no space (about 1-2mm) above the heatsink. So most of the air will go where the fins direct it. There is maybe 4-5mm above the fan, not ideal but should give enough air for it to be effective, even at low (silent) fan speeds.

You like?

Now your cooking with gas! That's a win there cuzzo. Thats more what I was thinking about how to get out the sides. Make pegs.

EDIT - Why are the rear fins blocked off?

 

[Cuzza]

Why are the rear fins blocked off?

I was wondering about that. Ostensibly they are blocked off because there is very little outflow available at that side, so I thought to block it completely so all the air can go to the front. Then I thought maybe the air on that side of the fan won't go anywhere at all and will just slow the fan down like it's pushing against a wall. Opening it up could actually help the fan overall. What do you think?

The other thing I was wondering about it the slots underneath the fan - they are not very wide, and the fins there won't be doing that much cooling anyway since they are away from the heat source, so getting rid of a few of them won't hurt and will increase airflow towards the front.

 

[Lazzer408]

I was wondering about that. Ostensibly they are blocked off because there is very little outflow available at that side, so I thought to block it completely so all the air can go to the front. Then I thought maybe the air on that side of the fan won't go anywhere at all and will just slow the fan down like it's pushing against a wall. Opening it up could actually help the fan overall. What do you think?

The other thing I was wondering about it the slots underneath the fan - they are not very wide, and the fins there won't be doing that much cooling anyway since they are away from the heat source, so getting rid of a few of them won't hurt and will increase airflow towards the front.

When an axial fan (airflow parallel to it's rotating shaft) is used in this way it will have no choice but to push the air out the sides like a centrifugal fan (airflow perpendicular to shaft). You see Zalman doing this all the time. Don't worry too much about not having fins below the fan. The air IS going to be pushed out the perimeter of the blades. Blocking the rear fins is only restricting the airflow because that's where the air is being pushed to. Depending on what's above your fins back there, the air will have no choice but to make that 90 and head upwards where the fins are open, but this is less efficient. Picture your heatsink filled with water. You want the water to flow out as easy as possible without asking it to change direction. That only makes turbulence. Opening those fins will allow more water to "spill out" from that area. If anything you should block the top of the fins to force all the air through the heatsink.

 

[Lazzer408]

Here's a small fan from a cheap harddrive cooler. I broke it off just for you. It's actually a very quiet fan but it shows just how effective an axial fan can be when up against a flat surface. The airflow stays close to the surface (the lighter is against the table) and you can see it's effect. I think you'll be impressed with just how well your heatsink design will work.

In all honesty it would be just as effective, if not more, to keep things moving in a line.

 

[Cuzza]

Cool bananas. So I've got the basis of a pretty good design in terms of fucntionality. But do you think it is practicable to make?

 

[Lazzer408]

Cool bananas. So I've got the basis of a pretty good design in terms of fucntionality. But do you think it is practicable to make?

It's twice as much machining time if you have to cut channels in 2 directions. If you can keep all your fins running in the same direction it's cheaper to manufacture. In fact, you could buy fin-stock already made and the machine shop would only have to cut the fins off the area for your mounting hardware and then cut the bevel for your keyboard clearance.

EDIT - Maybe you could find something like this and save some shop time. Search for soc771 heatsinks. Overall Dimension 89.0 x 78.5 x 25.7mm Anything close to what you need? http://cgi.ebay.com/Dynatron-T119-S...emQQptZLH_DefaultDomain_0?hash=item518d1d27d8

 

[Cuzza]

Next job is to simplify the design. Right now it's at the "ideal but unlikely" stage. I will trim it down around the edges, make it more basic.

Hey lazzer how much space above the fan do you think is minimum for it to work? I figure I could drop the fan in deeper if necessary, since you seem confident of the radial airflow it will put out

This pic shows the clearance it will have as things are.

I was wondering, maybe the low clearance on that side will make the fan less effective on that side, and if the fins are opened up at the other end (as we had discussed) more air will go that way. What do you think?

 

[Lazzer408]

Let me go see what that fan in the pic likes. one sec.

Ok the little fan I tried doesn't work well with any less then 1/2" space above it. If you only have 5mm above your fan then it's not going to work. Do you have room to mount the fan off to the side? I'll have to go back and look at your pics. Can you take a nice shot of the area where this cooler will go?

Cuzza. Can you get your hands on an old single slot videocard? The fan's in those are centrifugal and are designed to function even if another card was next to it. Were talking mm here. They suck! It's a good thing.

Like this. Get your hands on this type of fan and your golden.

 

[Cuzza]

I don't have one, but I bet I can find someone willing to part with one.

 

[Lazzer408]

I don't have one, but I bet I can find someone willing to part with one.

There you go. Toss a want add on tpu. I found a fried 3870 I needed some smt components off of to fix mine and it was free.

Look for a fried x1950 pro or gt. I know the pro was a single slot with a good fan. 4-wire PWM fan! And you can probably use the shrowd too. A little heat to conform it maybe?

Do you have Yahoo? I'm (edit) Kickerfox on it.

 

[Cuzza]

edit: no i don't have yahoo, sorry

PWM is no good, no PWM on my mobo! but that aside, any of those single slot coolers will probably do the job, i'll start looking.

just so you know, here's where the heatsink will go

compare:

 

[Lazzer408]

http://img.techpowerup.org/091101/hs placement.jpg

Can the fan be moved to the right? That way you can have full fins where the fan is in the picture. Not having PWM isn't an issue. The fan will run at full speed without the PWM signal wire connected. You can just use a resistor to slow it down from there.

Get yahoo. It makes it easy to point at stuff while your watching. lol

EDIT - BTW, use a smaller fan. A slight breeze on more surface area is always better then high cfm on less surface area.

 

[Cuzza]

Fan can only go where it is. You may not be able to see in this picture but the space is very very limited in all directions. I measured it up quite carefully and the heatsink I have designed uses ALL the available space.

Smaller fan? No way. The whole point of this exercise is to use a larger fan, so I can run it slower. The 40mm that's in there at the moment is too darn loud.

 

[Lazzer408]

Fan can only go where it is. You may not be able to see in this picture but the space is very very limited in all directions. I measured it up quite carefully and the heatsink I have designed uses ALL the available space.

Smaller fan? No way. The whole point of this exercise is to use a larger fan, so I can run it slower. The 40mm that's in there at the moment is too darn loud.

What I'm saying is the benefit from more surface area is greater then the loss of cfm from a smaller fan. The small fan doesnt have to spin at 5000rpm and move the same cfm as the larger one. It can spin as slow as the large fan and move less cfm but be more effective because of the surface area gained. Follow?

Put it this way. 20cfm across 10" of surface area is more effective then 40cfm across 5" area.

What's in this area? It would help significantly if you could vent the air out the back of the case. You'll probably heatsoak the inside of the case without any flow in and out. If the cpu fan could blow out that would keep air circulating in the case. I got it. Flip the mobo upside down so it gets fresh air off the bottom. lol

 

[Cuzza]

Yeah I get what you are saying, but with the positioning of the fan dictated as it is, using the smaller one isn't going to give much more surface area anyway. And the new heatsink will have much more surface area than the old one, big fan or small fan. so may as well go with the bigger fan.

compare:

I figure by reverting to 40mm fan I'd gain about 20% in the area of fins, and the blue area is short fins anyway, so I'd say 10-15% more surface area with smaller fan. I'd rather have the (substantially) greater airflow of the larger fan.

 

[Cuzza]

What's in this area? It would help significantly if you could vent the air out the back of the case. You'll probably heatsoak the inside of the case without any flow in and out. If the cpu fan could blow out that would keep air circulating in the case. I got it. Flip the mobo upside down so it gets fresh air off the bottom. lol

as things are there is very little airflow in or out, it certainly gets pretty hot in the case, i've run it all day and it doesn't overheat, but it's a bit worrying nonetheless

here's a close up. sorry its blurry, my camera battery just died so couldn't try again

you can see a few air holes in there. I don't think it's possible to vent out there but I guess it would be possible to cut a bigger gap there and make a duct to bring air in to the centrifugal fan (which I don't have yet so can't plan anything for). the centrifugal fan can mount much lower in the heatsink allowing space above it for the duct.

 

[Lazzer408]

as things are there is very little airflow in or out, it certainly gets pretty hot in the case, i've run it all day and it doesn't overheat, but it's a bit worrying nonetheless

here's a close up. sorry its blurry, my camera battery just died so couldn't try again

http://img.techpowerup.org/091101/SV402960.jpg

you can see a few air holes in there. I don't think it's possible to vent out there but I guess it would be possible to cut a bigger gap there and make a duct to bring air in to the centrifugal fan (which I don't have yet so can't plan anything for). the centrifugal fan can mount much lower in the heatsink allowing space above it for the duct.

I'm bent on having a duct in mine. I know it helps alot. It works much better that way since the cpu fan isn't bringing in hot air from inside the case. And what do you mean not much more surface area? That fan is like 1/3 the size. lol. I guess if you count "total" surface area. I'm kinda feeling out the "effective" area just above the CPU. I think the centrifugal fan and air duct is going to make a huge difference though. For the life of me I cant find this old 6800 I had kicking around. I'd mail it out to you if you can't locate a fan.

BTW I'm a fan of retro anything and I love the project. I have an old 70s Yamaha CS50 analog synth I thought about putting in a PC, touchscreen, and Reason 4.0

 

[Cuzza]

Thanks man. And thanks for all your help. I thought I had finished this project, but it looks like I'm going to be tinkering with it for a while yet!

 

[dr emulator (madmax)]

dam shame your not in my country as sir_real gave me an old ati fan very similar to the one in that pic
never mind ya projects coming along well