So, I've never made a mold before and I've never made a casting. I've been reading the Alumilite online examples and I went ahead and bought their starter kit. I figured if they can tell me how to do it online, they can have some of my money.

The first thing I did was use modeling clay to plug the openings:

I'm going to have a two part mold and I won't be able to have those openings in there. Note that I really should make sure to smooth things down on the prongs, but hey, I want to know where to cut those holes back in. I'm banking on having a faint outline there to guide me.

You can see things are pretty smooth still though:

Note that the surface I care most about is that screw connector shown at the top in that picture. I really want it to be level such that the fan will not wobble. But given the way I'm building the bottom of the mold, this will not matter that much:

I've elected to have the seam be on the base and I've pressed the retainer into the clay. At this point I need to clean up the top of towers (look in the lower left one) or I'll be cleaning up each and every cast. Another decision is whether I want to add some more clay to provide material to shave off for the base connections. I.e., I pretty well near went into the outer wall on my earlier attempt. I still plan to add some material around the feet when I prep the bottom half.

Oh well, I still need to figure out what I am going to do about the casting box, so I've got some time.

I'm also hoping the resulting cast will be strong enough. The demos produced car model parts and I think that will be sufficient. I'll have to see - I may need to get different casting resin.

So we can see here that it doesn't look like I can shave enough off:

I went to Hobby Lobby over lunch and it looks like I going to need to make a mold and tap out some holes. I saw some Alumilite products that look like they would be durable plastic.

The plan would be to cover the screw holes and take a mold. Hmm, I might also look to add a bit of width on the hole bases. I.e., I probably need another millimeter or two of wiggle room. 1 for the hole and 1 for the rim.

But once I have a mold in place, I will also be able to make my own spares and not be so cautious with what I have. :->

Here is a picture of the CPU retainer bracket before any modifications:

All of the holes look nice and round.

I marked one corner (so I was always testing the same fit) and started in on the holes with a dremel. The intent is to shift them about 1mm up. I'm not using calipers or anything at all scientific. I'm doing it all by eye. Note that this means I might have the right side fitted correctly and not the left. And I may end up over compensating. My inspiration are those oval screw holes on older hard drive brackets.

I'm fitting the lower left and upper right screws in when I'm doing my tests. I leave the screws loose and move the bracket up and down to check the fit. Here we can see the original offset:

And here we can see the new and improved offset:

At this point, I'm getting leery of making more shavings. If we look at a closeup of one of the holes:

you can see that I may end up going to far. I have no clue what will happen as I tighten the screws later. I don't want a crack.

Just by eyeballing the remaining clearance needed and the bracket to be carved off, I'm not convinced that that this is plausible. Right now I have a working bracket for the stock CPU fans and I'm flashing on the old adage, "Measure twice, cut once."

Also, I've got another problem on the daughterboard. You can see that even unconnected my test blank is not going to fit:

There is a header there (for the CPU fan) that is blocking lining this up correctly. I shaved down the outside of the retainer and got it to fit:

I got the Dremel out and started shaving back the mounting holes for the CPU bracket. I think I can make it work. But on my last shave, I got a little impatient and made a cut bigger than I wanted. It wasn't damaging, but I realized I'm too groggy.

Anyway, I'll add pictures tomorrow and maybe continue on.

I've been assuming all along that the problem was the cpu fans. I did another search and came up with someone who installed a Zalman: here and write-up here.

One of the pictures had a closeup of the case fan, so I searched for it and here is a description: here:

If noise issue is no problem for you, you might want to consider this Delta 120mm fan. It features a whopping 152 CFM of airflow at 53 dBa. For a 120mm fan that is 38mm thick that isn't too shabby. This high end Delta 120mm fan is often used in rackmount server rooms where noise is not an issue.

I can't swear, but I think the CPU fan is a:

Tach output, 9 blade, very high performance 40CFM, moderate noise 38dBA,

Okay, it is clear Sun was getting a good deal on server room fans and not desktop fans.

But, as a server, these things kick butt!

If I wanted to keep the stock fans, I think I would look into building a box to house the computer. I've looked at noise dampening from an audio perspective (think garage band) and it looks like a simple box with 2 layers of drywall might do. Sounds heavy. I'd probably consider a light wooden frame and the sides made out of a double layer of cork. This would not be a load bearing box, just something that could be placed over the computer.

You would want airflow (the trade-off is classically sound versus temperature.) with a means for air to come out. Perhaps a low blowing case fan? :->

I think I could build something like that for much less than the sound reduction boxes I see online.

Hmm, too late at night - but I wanted to capture the thoughts on the noise reduction box!