Todays update:
Last night I cut up a piece of polyethylene, and chopped the ends of the barbs off. Today I started by drilling three 8.5mm holes for the barbs, then filed them out to the 12.5mm od of the barbs. The drill was the biggest I had, and also was the same size as the ID of the barbs, which was nice.
Ive justed tested it with bluetack to seal the base, that part didnt leak atall. The barbs did though, but that should be easy to fix when I seal it properly.
In the test it wasnt too restive and I had a nice amount of flow even with only the middle channels used, and half filled with bluetack. The tubing from the Y connector gets kinked because the angle is too close together.
Yet to do:
1. The barbs are 8.5mm ID and so doesnt cover all of the channels. On the inside of the top I will make the holes long enough to cover all of the channels and slope into the barb. The inlet Hole will be made long enough for all of the channels aswell, but will be reduced in width so that the flow speeds up as it hits the area over the core.
2. Drill holes in the top and base to fix them together. In the pics I used the mounting holes for this.
3. Seal the barbs to the top, and the base to the top.
1 and 2 are now done
pics attached.
I might add another layer of polyethelene on the top with some channelsin to combine the outer channels into just one channel, meaning I would only need one barb and no Y joiner. I think it would make it look better but takeup another pci slot. I have 5 unused pci slots, so it wouldnt matter
Doing this would not be easy though. I would have to buy a bigger drill (11.5mm probably) first. Then I would need many holes to about the same depth close together. then I would use a cutting disk and a 6mm milling bit (not sure on name, but can cut sideways unlike drills..) to remove the mess I would create. I would only go 7mm deep at most, so the layer would still be one peice with the center inlet going straight through to the middle layer.