More LED Testing

posted Feb 11, 2013, 11:06 PM by Andrew Stock
So... I didn't do nearly as much this weekend as I wanted to. I really wanted to get started with priming and painting, but the temperature outside was far too cold... so it would have messed up the finish I think. Life has a way of making other plans for you, I guess.  I did still do a few things that are worth sharing!

First of all, I continued work on the reservoir a bit. I received some various bits and pieces of acrylic to try different shapes and sizes and see what I could do to diffuse light better. Unfortunately, none had the effect I was looking for. I tried rods, half-rods, spheres, semi-spheres, cutting long grooves into the back side of the prism... not much seemed to make a difference in how diffused the light was. Here are some experiments I did, with descriptions of what you are looking at attached to each video:

Test 1 
Test 2
Test 3
Test 4

I did many other tests, but most of them proved to be a detriment (they actually focused the beam, or scattered the light into a rainbow) rather than help. I think when it comes down to it, the LED lights on my strip are too far apart, and the acrylic I am trying to light is too thin, to accomplish the look I want.  Naturally, I started poking around online for a solution... and come to find the same company that manufactured my current LED strip made a Version 2 recently that is double density! I snapped up a couple of meters, and we'll see how it looks!

Anyway, in the meantime, since I still needed something to do this weekend, I went ahead and prepared the prism housing with the anticipation that the double-density strips will absolve the problems with light distribution I am having.  First, I cut a channel into the bottom of one of my prisms approximately the width and depth of the LED strip:

Next, I laid the strip in the channel to make sure it fit. There is a slight overlap at either end with this kind of strip that I am hoping I won't have with version 2, but there's a distinct possibility it will. Also, there are contacts at either end of the strip that I will likely want to wire up so that I can chain this on to another location instead of running another lead from my Arduino... so I need some way to reach those contacts. I trimmed the prism with the channel slightly, so that when the top prism sits on top of it, there is a slight gap on either side, like so:

When laid into the housing, it still overhangs slightly, and there's still the matter of what to do with the wiring. When I glue the tube reservoir into the housing, the bottom area shown here will be completely sealed and set against the bottom of the midplate. 

A simple solution came to mind... cut a port in the back of the housing like so:

Now, I can glue the bottom in place and the wires won't be in the way. Additionally, this port will be completely invisible as the prism will be covering it from the front, and I'll have 'other stuff' obscuring the back of the housing (more on that much later... )

Just for the heck of it, I lit up the current light strip with the unit all built. It's not glued together yet, since I will be replacing the Version 1 strip with a new Version 2 soon... but I couldn't let all of my work go without immediate reward! 

Also, a brief video, so that I can compare it to what version 2 will look like when I get it!

Anyway, enough of that for now... on to something else!  I did a little shopping at the local hardware store in preparation for painting, even though it wasn't shaping up like I would be able to paint this weekend:

I also started figuring out what I wanted to do with cable routing from my power supply. As you can see from this shot, my space is very limited in this case:

I'll need to make cuts in the midplate somewhere in order to pass the ATX cables from below the midplate up to the motherboard and peripherals... but I'd like to do it in a very 'stealthy' way. Also... there's the little matter of ventilation for the power supply. There's only a few millimeters above and below the power supply. In the current installed configuration, the fan is butting up against the midplate. I'm not sure if that's enough room for ventilation... but then again, this power supply only activates its fan when it is hot... and it's rarely on if ever... so... 

I played with the idea of cutting a hole in the midplate about like so:

I don't think I like it though... so I am tempted just to see how it goes with limited ventilation. 

I also played the location for CPU power cables to come up through the midplate... and I think what I will actually do is cut out a section of the motherboard tray and feed the cables under the motherboard. It's a little hard to explain, but here's where I am thinking of routing the cables (I just stuck a spare cable I had under there to make sure it fit, and to illustrate my idea. The final cables will obviously be sleeved. :

To fit the cable there, I'll cut a section out of the back side of the midplate, as well as a bit of the motherboard tray just above the markings shown here:

I plan on doing something similar with the ATX power, and the PCI-E power cables too. I'll cut a similar section like above, route the cables along the back of the motherboard tray, through an opening that will be hidden behind the motherboard, out from under the motherboard, and into the power ports. Clear as mud? 

Anyway, next time I'll keep going with the cable routing preparation. I also hope to get the new LED strips this week. See you next time!