Constructing your own Sabertooth duct-plate

[BonzaiDuck]

I've been "renovating" an old Stacker 830 case, and decided to try my hand at motherboard ducting again.

The interesting thing about this Stacker: I had fitted it with a Cross-Flow fan -- a 13+inch-long barrel fan that is supposed to intake air from the case side panel and blow it across the motherboard. But that doesn't suit my purposes with this: I installed the fan for exhaust. The duct-plate lies on top of the fan and extends toward the rear of the motherboard.

Doing something like this with Lexan is a real chore. While folks might work with different cases and find a different strategy for fan-deployment with a duct, it could be an exercise in integrating interior case features with a duct that is only supposed to cover the motherboard.

Here's what you do.

Go to the motherboard-maker's web-site, find your board, look for a "gallery" of pictures, and find the picture "reconnaissance photo" from the vertical angle to the board. Copy and save the picture.

Load the picture into a graphics-design program like Corel Photo Paint. Crop the motherboard picture to the very edge of the rectangular motherboard. Then, with a "resample" or "resize" feature, change the size to match that of the motherboard to the fraction of an inch.

Print out the mobo photo in 11"x17" paper. [An ATX board like mine is about 9.6"x12", so you'd use this "tabloid" paper size.]

You can now draw your duct on the reference photo, with room to spare if the duct overlaps the mobo. Paste the paper on the thin type of white cardboard you could find at COSTCO used as separators on a pallet of paper-towel rolls. Then cut the board pattern, and use it to score its shape on a Lexan panel. After that -- the tedious work of scoring or sawing with a coping saw.

I'm not sure how much folks would lean toward ducting these days, but it would help for either air or water cooling. The essential objective would be to exhaust air immediately to the case exterior from under the duct plate. You'd need to find your own solution for a dedicated exhaust fan. For water-cooling this actually might be easier compared to an air-cooled setup with only one primary exhaust fan.

If the thread draws interest from my colleagues here, I may try and post some pictures of my recent work, together with a list of tools, glue options and other useful things.

 

[Fallen Kell]

I have debated this myself from time to time. I think the biggest issues that gets in the way is dealing with offsetting the plate high enough from the motherboard components to promote easy airflow while at the same time restricting it enough so that the fan can produce enough suction to pull air across the components, all the while dealing with heatsinks and heatpipes that are raised up on the board and and not interfering with riser cards/boards such as RAM, graphics, etc...

 

[XavierMace]

The reason you don't see ducts that often on desktops is most of the the time they aren't moving enough air volume for it to really matter. Servers and workstations move a lot more air and ducts are pretty much standard on them.

 

[BonzaiDuck]

If I had to mount 40mm to 70mm fan(s) on the duct-plate as part of the design -- similar to the Sabertooth duct -- I would definitely want the duct closer to the motherboard.

But this Crossflow barrel fan pulls air equally from the front side of the board -- from both the top and underneath. Since the mobo pan on the Stacker is ventilated with 1 cm diameter holes, it is actually pulling intake air from outside the case, and interior air from the top of the board and exhausting both streams.

So the duct, which sits at least an inch and a half above the mobo, is about .5 cm below the bottom fin of the heatsink. The duct is cut to allow for careful placement over the fins like a necklace. You just put the duct in a vertical position to line up the rectangular hole for the cooler and push it into place.

Because it sits that high, there is a "skirt" around the intake side of the board, allowing much air through a small aperture at the rear side of the chipset heatsink. Similar refinements pull air from the back of the board across the VRM heatsinks, through and across the RAM.

This was a rare opportunity to use the Crossflow fan effectively. I was almost planning to throw it away. But your point is well taken -- the use of expansion slots complicates the design and makes for extra work. For this, you'd have to settle on a "permanent configuration" of PCI/e devices unless you want to modify the duct again.

I knew this one would be a simpler prototype for systems like that, since the system will perform as a server with some small PCI-E controllers. No graphics card: I'm using the Intel 2500 on the chip.

Now suppose I want to move the server into a piece-a-shit case that still has decent ventilation? I reclaim the Stacker, put the duct on the bench and start refining it for gfx and expansion cards.

I'll try and take some pictures. My computer stuff today is full-time maintenance, and I'll get around to it.