Bench Testing and Tools

posted Jul 24, 2012, 11:42 PM by Andrew Stock   [ updated Jul 24, 2012, 11:42 PM ]
Time for an update! 

First of all, as shown in my previous post... EVGA finally sent me a motherboard that works! Hooray! To get it working, I had to pick up a new processor... and while I was at it, I decided to pick up a PSU tester JUST to make sure it wasn't my PSU blowing things up. 

Fortunately, the PSU for my bench tested out fine.  I also grabbed that little tail LED so that I could do some more Acrylic/light testing. 

Here's the bench, up and running on the first try!

(I moved it into the living room... it's been 100F outside the past week or two, and the heat in the garage was getting unbearable. So the wife gets to deal with my workbench floating around the house with me. )

There's that silly "stasis chamber" on the motherboard. As far as i can tell, it's just a useless chunk of plastic with a pulsing LED behind it. Other than that, the board looks great and performs admirably. It's been running at 100% CPU (torture testing with Prime95) for about a week now, and no crashes or problems yet! I haven't been wasting all that burn in time, of course... I've been testing! Stand back, I'm doing SCIENCE!  

Okay... so it's not super scientific... but it's sufficient for what I am trying to determine anyway! It helps that I moved my rig into the house... so the temperature is somewhat controlled (only varying 5-10 degrees F instead of 30-40!) I'm just measuring the air temperature compared to the water temperature over the course of a day or so, measuring at random intervals. I then subtract the air temp from the water temp to give me my Delta T (difference in temp between water and air), which gives me a fair idea of how efficient my radiator setup is performing. Assuming that my heat generation is consistent (which it should be, the CPU is 100% pegged using the same wattage the whole time), I should have a pretty good basis for comparison. 

So far I have only tested two configurations... The first setup is rows of fans on the outside of each radiator pusing air into the center of the 'radiator core', and there is a gap between the radiators where air is vented up/down. So the orientation is basically Fans > Radiator |air baffle| Radiator < Fans. This orientation yielded a Delta T of around 1.875 degrees F. Pretty darn good! That means the radiators were able to keep the water temperature at nearly air temperature. Keep in mind that a Delta T of 0 should be nearly impossible to accomplish... so yea. Pretty good. 

The second setup I tested was similar to the first, but I just reversed the airflow. Now the fans are configured to pull air from the center of the radiator core, so the setup goes Fans < Radiator |air baffle| Radiator > Fans. As you can see from the second chart, I ended up with a Delta T of 3.88F. I knew that fans in 'pull' configuration weren't as good as fans in 'push' configuration... but I had no idea it would make THIS big of a difference! So it's clear that configuration 1 is superior, and that narrows down my options to only those that consider fans in push mode. Neat!

(Yes, I know, there are other variables at play here that could shift the balance in favor of one configuration over another... but for the highly un-scientific needs of this project, I will consider this level of testing to be sufficiently similar to the performance I will see in 'real world' scenarios, which is why I am doing it this way... because... well... my computer will need to operate in the 'real world' at some point. )

Anyway, while all this was going on in the background, I decided to play around with acrylic some more! Always fun to experiment. This time, I wanted to try out cutting Acrylic with a power saw, joining it with superglue, using a corner mold, etc... all tasks I will need to do in some capacity for the project. First of all, time to meet the power tool... a good old miter saw!

The nice thing about using a miter saw is that it has the angles printed right on the base, making it very easy to get exact angled cuts for joining. 

The blade on this saw wasn't designed for Acrylic specifically... but it has a pretty good teeth-per-inch rating on it, so it should be passable. We'll see though.  Safety first! In the small experiences I've had with Acrylic so far, this stuff flakes off like crazy and gets extremely hot... enough to burn your hands should a stray piece land on you... 

First cut! 

Pretty rough... but I rushed it a bit. Nothing a little liberal sanding cannot fix! 

Now to try an angled cut! 

Also a little ugly. The blade on the saw clearly isn't sharp enough or cut out for Acrylic, as it is melting the stuff rather than cutting/shaving it.  As it goes through the acrylic, it should be flaking off like snow... instead, I am getting cotton ball-like webs and piles here and there: 

Fail.  Guess I'll be buying a new blade once I can find a good store that sells Acrylic tools. I need some Acrylic drill bits and glue anyway. 

No matter, though! We can still fix the scrap pieces I am working with, and proceed onward. Time for some sanding! I used P250 grit for this work, as there was a significant amount of correcting that needed to be done.

Looking better... 

Much better! I cut a second piece using the same process... now to try out joining them! I read somewhere that using IPS Weld-on #3 is about the best stuff you can get for 'highly visible' joints such as what I will be doing on the front of my case... however... I don't have any of that yet, and couldn't find it at the local hardware stores. I also read that super glue can be used in a pinch, though it usually ends up looking rather ugly by comparison. Fortunately, I have plenty of super glue... so let's see how it goes!

I used a metal corner beam that I found at the local hardware stores as a 'mold' for my 90 degree angles. I put a line of superglue down the crease, then clamped it to the mold to let it dry for a few minutes.

And the result:

Not too bad! I only spent a minute or two sanding, so the edge was not perfectly matched. I also stopped at 250 Grit rather than using higher 1000 or some of that acrylic polish that helps get a perfect surface... so I can see this working very nicely once the joint is uniform. Even with a quick sanding job and cruddy old super glue, the weld ended up being almost invisible... here's a look at it from the front!

Pretty slick!  Looking forward to what I can do with a bit more time and care, on some higher quality Acrylic with appropriate tooling and adhesive!

Next... I went on a bit of a hardware shopping spree...  I've only just started collecting real power tools and such... most of what I have done around the house could be accomplished with a table saw, hand saw, and simple wrenches/screw drivers/drills. Now that I am getting some serious detail work done, I thought it was time to get some accurate tools for finer work. First, I raided my fathers garage for any old tools he was no longer using... he gave me free reign so long as I 'treated them nicely.' He's seen what I am capable of, clearly. 

First tool, a table router! This should come in very handy for some of the edging to get my Acrylic window mounted flush against the case wall. Should also be great for using a template to cut identical case windows on either side. 

Next, a rotary sander! Beats the heck out of manual sanding for pieces that require a lot of correcting. Finer jobs are best left to manual sanding of course... but this will really speed things along for working with metal I think. Might be a bit much for Acrylic... but we'll see. I can also get a buffing wheel for this to polish my Acrylic and such. 

Third... an old, dusty grinder! Should be great for evening up edges on metal cuts, and I can switch the wheels out for buffing and such too. 

Finally, who can forget a the trusty old table saw?

I also raided a multitude of routing bits and such... can never have too many tools. 

There was still one tool I was planning on getting for this project though, and I finally decided to just go out and get it... a shiny new drill press!

I also cleaned up some of the garage and put together a work area for all these great tools... now I have a pretty solid work area for all of these bits and pieces!

Anyway, that concludes this update! All the tools are in place, save for a few bits and blades... I think it's time for me to go and order some Acrylic now...