Sleepy – the Sleeper-PC I'm building and then raffling – is almost finished. Today I design the distro plate and the pump/reservoir combo for the water cooling system. Unfortunately, the side effects of too much milling are bringing my progress to a grinding halt.
I originally wanted to mill out the distro plate and the pump/reservoir combo myself. But I'm afraid my skills as a CNC cutter are, to put it nicely, wanting. Before the parts are ready to be milled, I must first assemble them in the CAD tool Fusion 360.
I chose Fusion 360 because it's free for private users. In addition, Alex Banks from bit-tech published a «How to» guide on Youtube for creating a Distro Plate. The step-by-step guide is worth its weight in gold to me as a Fusion 360 newcomer. That's why I'm not giving you instructions here, but telling you what I thought about when designing the parts.
I keep the pump/reservoir combo and the distro plate in a sandwich-like shape. They consist of a base plate and a cover plate screwed together. The pump is mounted behind the base plate. The liquid flows between both plates through channels. On the outside, sealing rings ensure that no water will leak out. The holes for the ports are on the front panel.
The pump/reservoir combo
Last time, I created paper templates for the pump/reservoir combo and the distro plate. Now I know how big the two parts are and where to place the ports.
Since I like challenges, I start with the harder task: the pump/reservoir combo. It's my first time ever using Fusion 360. For safety's sake, I follow the instructions in the video at the start. First I place the pump – as shown by Alex – in the middle. That makes sense in my case: my pump/reservoir combo is too small to place the pump on the bottom or anywhere else. The four small holes around the large pump opening are for mounting the pump onto the backside.
Unfortunately, Alex Banks only makes a very basic pump/reservoir combo with straight inlet and outlet channels in his guide. If I copied the template, I wouldn't be able to place the ports where they're needed.
So I'm adding more channels. Before starting, I had the idea to design the channels as two half-circles – one on the left and one on the right side of the pump. This would have painted a wonderful picture of a stylised night sky on Sleepy's ceiling. I quickly rejected the idea. On the one hand it seemed too cheesy to me, on the other hand there wouldn't be enough room on the small pump/reservoir combo.
Due to my lack of experience with Fusion 360 and the limited space available for the pump/reservoir combo, I decided to extend the two original channels. In my version, the fluid meanders through a total of eight channels, four per side, which I connect to each other.
I also add another short channel in the upper right corner, as seen from the front. This will serve as a fill port, strategically placed at the highest point. Filling the water cooling loop will be as easy as possible.
Then I add the channels for the sealing rings, the ports and the screw holes. Here's what the finished design looks like:
The pump/reservoir combo isn't everything I need for water cooling. I'm looking for an easy and simple way to empty the cooling loop. Which is exactly why I design a distro plate in Fusion 360. It stretches from the lowest point of the loop to the radiator. The plate is therefore ideally suited for the emptying port.
Thanks to the template I made earlier, I know exactly where to place the port. Due to the limited space available, the distro plate is relatively slim at only 4.5 centimetres in width. Apart from that there's nothing else to say about the part, except that my model for it looks like this at the end:
Who's milling these things anyway?
After creating both components in the CAD programme, my search for someone to mill the parts for me begins. I ask various providers in Switzerland. As these are individual orders, the price points are rather steep. All in all, the pump/reservoir combo would run me CHF 625.– while I'd have to pay 370 Swiss francs for the distro. Relatively high prices, due to the fact that these are specialised parts. I don't know if I can justify the high price to my superiors.
For comparison, I ask for an offer from Protolabs. Protolabs is an internationally active online provider of prototypes and small series. Even outsourcing production abroad doesn't really cut costs. At 420 francs, the distro deal is even more expensive than the Swiss offer. The pump/reservoir combo is «only» 588 francs with this provider.
Unfortunately, my superiors are buying none of it. Hey, I'm an editor, not a salesman. In order for Sleepy to work as I planned it, I order the distro from the Swiss provider akuplex. The distro is more important to me than the pump/reservoir combo, as it contains the emptying port. It's important to me that Sleepy's «service» be as simple as possible. Instead of my self-designed pump/reservoir combo, I now use the Alphacool Laing DDC310 with an acrylic top.
Testing and hoping
After a few long days, the distro finally arrives: It sure looks awesome, and even though all that effort for the pump/reservoir combo was for naught, I'm still happy about the distro plate.
Next up, cutting the gasket to size. I decide to stick to a further video from bit-tech. In it, modder Alex Banks explains what to look out for when making sealing rings. Fingers crossed I do everything right.
I choose silicone as my material as it's the first thing I can get my hands on. I cut the sealing ring to the correct length and glue it together with super glue. Now I just have to put it into the channel and screw the front to the back. For this, I use M4 screws. Bam! The distro is ready.
Before I mount the distro plate into Sleepy, I test it for leaks. I create a small water cooling loop with the distro plate and pump. This will also test if my DIY construct can handle all the pressure it'll be under I run the test over the weekend.
When I arrive on Monday, one thing is clear: this distro plate is tight. I can install it without hesitation. But before we go there, I have to finish my work on Sleepy. And you'll hear more about all of this next time.
You can win like this: Over the coming weeks you can read about the sleeper PC project on Tuesdays and Thursdays. At the end of the articles I'll ask you a question with three possible answers. You can find the correct answer in the article itself. You get one point for every correct answer. Answer as many of the questions as possible correctly and you will make it into the final draw. The draw will decide who wins the PC.
What material is the sealing ring for the distro plate made of?