Plastic under stand case for electronics of DIY LED GB Build

[donb]

OK, I recently built a single Lumia 5.2 on a Makers LED heatsink. See this document for more:

http://www.nano-reef.com/topic/343275-52-install-documentation-and-ideas

Since then, I have been gathering pieces and parts to make a control box to hold the controller, drivers, 5-up boards etc so that I could enclose them, get them away from the water while still maintaining some portability. The plan here is to (somewhat neatly) put it all in a case and mount the case to the inside of the door of my stand. Then have a cable from each side (input/output) from the Lumia to the box and some type of plug so I can easily move the box and lights in the future. So here goes….

I went to www.polycase.com and snagged one of these. It is the part number DC-96F. I chose this model because it is 10" x 6" x 3" and I wanted enough room inside for the Storm-X controller and up to 4 Coralux 5-up boards with LDD drivers installed. Right now I have 2 boards and wanted easy future expansion to a total of 4. This model also has predrilled mounting tabs on each end.



If you use this case, watch what cover you get. The default is a smooth recessed top that does not match the texture of the rest of the case. I think the textured matching top would look better. But it is going under the stand so out of site out of mind (kind of).

Next I set out to make the cables from the light to the new case under the stand. From each heat sink I needed to get the 10 wires from the Lumia 5.2 downs to the case. I decided to use 5 strand cable (x2) and a 5 pin din plug/socket to make the connection to the case.

This is the wire I used and the din 5 pin connectors:

http://www.allelectronics.com/make-a-store/item/5cs22/5-conductor-shielded-cable-w/drain/1.html
http://www.allelectronics.com/make-a-store/item/din-524c/5-pin-din-socket-240-degree/1.html
http://www.allelectronics.com/make-a-store/item/din-524/5-pin-din-plug-240-degree/1.html

Cut the cable to length (around 7.5’ for me to give some extra). Then remove the sheathing from one end to expose the individual wires inside. One of the wires is an uninsulated wire that provides a drain. We don’t need this one. The other wires have green, brown, black, white and red insulation. Doesn’t really matter which one goes where in the din connectors, just as long as you keep track of which one goes to each pin. (The pins are numbered on the back of the shell) I removed the pins from the min-din plug, tinned, soldered and heat wrapped each wire to a pin like this:



Now put the pins back into the shell, add the metal housing and rubber boot. Repeat this for the other cable following the same color pattern of the first.



I took about 8” of cable and removed the outer sheathing. Then stripped, tinned, soldered, and heat wrapped each wire to the socket side of the connectors. To make things easy, I made sure the color of wire soldered to each position on the socket (they are numbered also on the connector) matched the color I soldered to the plug. Again, (I don’t think) the order of the colors doesn’t matter, just that the plug pin color matches the socket pin color.



Next I used a step drill to machine two holes in the side of the case, one for each din sockets. If you haven’t seen one before this is a step drill



These things work great for machining holes in any kind of plastic and are stepped off in 1/16” increments. If you need to drill a fracture free hole in plastic, you need one. Only downside is that this type doesn't work well over 1/8" thick plastic.

The case now has holes for the din sockets and a 5/16” hole for a grommet that the power supply cable runs through for the 5-up. When I order parts for the next round of Lumias I add, I am planning on DC pin type connectors to replace the rubber gromet.



I used a #4 x 3/8” bolt to hold the panel mount din socket to the case. These connectors are at the top of the 10” side of the case. I plan on putting a second and third grommet (DC pin connector) on each side of the first for the other two 5-up power cables and 4 more 5 pin din connectors for the other 2 5-up boards.

Now, to the inside of the case where all the goodies go. Instead of purchasing the matching internal mounting panel that polycase sells, I just took an old piece of ¼” scrap acrylic and cut it to fit into the bottom of the case. I made mine so it covered one half of the inside of the case. Looked like this



I had to notch the plastic mounting plate to accommodate the lid posts in the case. Once the plate fit around the lid mounting standoffs, I marked and drilled holes in the plastic above the mounting bosses molded into the case. Then 4 - #4 x ½” metal screws from the hardware to mount the plastic to the case. This gives me enough room to stack 2 pairs of 2 5-up boards on each end.

I placed the 5-up board on the plastic, marked and drilled a mating hole for each mounting hole in the 5-up through the plastic. The board is mounted to the plastic using a ½” #4 nylon standoff and a #4 x ¾” nylon bolt and nut. This is what that mounted board and one of the mounts look like.

 

Now mount the other 5-up board onto the plastic mounting board the same way of the first. I am not using this right now, but will in the near future when I add the next pair of Lumia to my tank. Eventually I will get another set of longer standoffs and longer nylon bolts/nuts and stack the 3rd (4th?) 5-up board on the first two.



On to cutting a hole for the face of the Storm-X and control knob in the top of the case. I used a Dremel with a plastic cut-off disk to remove much of the material. Used a the Dremel drill bit to cut holes and finish the rough removal. Finished it off with a smoothing disk and then some sand paper to take off the edges. Added a hole on one side to accept the control knob. I kinda lost track of the cut-off disk on the upper left and scored the case a little. This is why I don’t do this kind of stuff for a living! This is it:



I am still looking for nylon bolts long enough to pass through the Storm-X board and up through the side of the case. Local hardware stores have been no help so far, so right now I just passed the wires through the cutout and lay the controller on the top of the case.



To wire the cables from the lights to the board, I took the same color from each din connector and connected to the matched pair on the 5-up board making sure that the wires from the top din connector went into the + connectors on the 5-up and the matching color wires from the bottom din went to the matching - connector on the 5-up. Next, I wired the Storm-X controller the other side of the 5-up just as one normally would.

After debating with myself for several weeks, (ok, maybe it was an hour or two) I decided to solder the cables to the wires on the Lumia molex connectors rather than using a terminal block. I looked back at one of my original goals and that was to protect the wires/hardware from saltwater and felt that solder and heat shrink wrap would do the best job of that. So, I tined, soldered and shrink wrapped each wire making sure the same color from the 5 wire cable matched the color coming from the molex connector from each side of the Lumia.

After pulling the two wire cable for power through the grommet connected 12v power to the 5-up, I put the lid on the case and used the mounting holes in the tabs to screw it to the inside of the stand’s door. Pulled the two five wire cables from the light down to the box and plugged in the din connectors. Connected the 5-up power cable to the power supply and plugged in the DC power supply to the Storm-X. Everything worked as it should (very lucky) and now all the electronics are tucked into a plastic case, yet accessible by opening the door on the stand.

OK, that is it for now. Sorry for the size of the images, but I have never posted a message with a bunch of pics and didn't know what to expect. I'll try to resize and replace this weekend.

 

Don

[aesp533262]

Id be lying if I said I wasn't spending time at work today trying to figure out how to solve this exact problem. Nice write up.

[donb]

Thanks for the comp. I have to admit that I MIGHT have used some down time at the salt mine to work on stuff like this.

 

The other thing I debated was the connector to use. the same place has a 10 wire cable and then you could use a smaller 10 pin din or similar and have just one wire/connector per light. I didn't because my skills working with small, teeny tiny stuff and soldering same is not to good. I have a 2" DC fan that came out of a pico computer case that I am going to mount in the bottom to blow outside air through the drivers/controller with some small vent holes in the top. Right now I just have the lid off the box and relying on convection cooling.