hi Ned i am watching this with interest. looks really neat and tidy. one thing i do want to ask is on the screws . are they metal or plastic. if metal did you use a fibre washer. keep the story coming mate.. len
pride before a fall.
The screws are s/s with a black treatment to prevent any type of corrosion. I have had a few head up ass moments of late and ordered nylon washers. Luckly, I received a high high melting point nylon. I should have ordered teflon or fiber. After a lot of consideration, I would find the head diameter of the screw, then order a washer that comes as close as possible. Over size, not under.
The Star mounts are symmetrical, the die is not. If you look back in the thread to the picture of the die, you will see what I mean. So, it's important to pick a washer that will allow it to lay flat on the Star.
LEDs need wire
Look closely at the Stars and you can see where the thermal compound has oozed out around the star. If you look at the Star in the lower right, you will see the results of a broken tap. With a lot of work, I managed to get the tap out with a tap extractor and help from a few naughty words. OK, a lot, seeing as how I did not have the right size. Another trip to the hardware store.
Walton Tap extractors made this possible. Sadly, the tip of the tap had broken off and I needed to drill it out. No more tapping blind holes! By the time I was finished, I needed to fill the hole with metal filled epoxy, re-drill for 6:32 (better thread holding ability).
So much for that.
Onward to the soldering.
Know from the start that the Stars and the will do their damnedest to remove all the heat from where you are applying it. This means that the little 20 or 30 watt soldering iron will simply not cut it. If you have a soldering station rated at 40 watts or above, you have a chance. Set the temperature on the soldering station to 800 degrees F.
Pre-tin the the wire and the pad. To do this, apply the iron to the pad and start feeding solder to the point where the iron tip meets the pad. Apply just a coating, not a glob. This picture gives you the basic idea
Do the same with the wire. Strip about 1/2 inch of the insulation off the wire with wire strippers. Twist the wires together and apply the tip of the iron to the wire and feed just enough solder to coat it. You should be able to see the definition of each of the wires when done correctly. If you have too much solder on the wire, clean the tip and touch it to the wire. It will wick the solder away, back to the tip.
Now, with wire cutters, trim the tinned end to about 1/4 inch and lay it on the pad. Aim the wire toward it's destination.
Put a small bit of solder on the iron tip and apply it to the pad and wire. As It get's hot, feed a small amount of solder until
it flows about the wire and pad. In the picture above, notice the angle of the tip. You need to transfer more heat to the joint to overcome the action of the heatsink, so lower the angle so more of the tip is in contact with the wire and pad.
The wire will become to hot to handle with your fingers, and, as you don't have three hands, have a sacrificial buddy hold it.
Just kidding… Use some thing heavy to hold the wire in place. A small bag or sock filled with sand works well.
Remember not to move anything until the solder has solidified.
This is the best I could do as a close up, The joint has enough solder, yet the wires are clearly defined.
This is important and most folks don't bother because they have never been told about it.
The brownish material around the joint is the Rosen Activator. It's in the core of the solder and cleans the metal so a good joint is possible. While most Rosen is not active after soldering and it's save to ignore it, this is an exception. Rosen core is active at roughly 150 degrees and up. This means that when the lights are on, it's possible for the flux to become active and, over time, damage the solder joint.
So, go spend the $$ and purchase a spray can of Flux remover and clean all your work. You will need a couple of small, inexpensive stiff brushes also
Now, if you are really cheap, you can always use turpentine, followed by a Isopropyl Alcohol rinse. NOT rubbing alcohol, which is 30% water. You need Anhydrous USP 99% Isopropyl Alcohol. It should be available at your pharmacist. You will need a couple of small, inexpensive stiff brushes also. In the States, we call them acid brushes.
Tap removers http://www.waltontools.com/
Flux Remover Techspray - 1651-16S - Flux Remover, Aerosol
Wires need connectors…and controllers… and power supplies
Here we enter a jungle. I have 4 (or soon will have) heatsinks that need to be attached in some way to the controller. That will involve 8 wires per heatsink or 32 total.
Having a bundle of wire that is soldered in place at beginning and end is out of the question. So, it's connector time.
This brings other items that need to be considered.
1) The location of the power supplies,
2) The location of the controller,
3) How the panels are going to be mounted and suspended,
4) Murphy. (The British stage magician Nevil Maskelyne wrote in 1908:
"It is an experience common to all men to find that, on any special occasion, such as the production of a magical effect for the first time in public, everything that can go wrong will go wrong. Whether we must attribute this to the malignity of matter or to the total depravity of inanimate things, whether the exciting cause is hurry, worry, or what not, the fact remains."
In the beginning, I had considered hanging the whole thing from the ceiling. This proved to be an unworkable for many reasons, least of which was the attitude from my wife which starts "Where do you get those *&^%$# ideas? "
On to Plan 2, I would build an enclosure for the panels and put the controller and power supplies in it as well. Then I would mount it on top of the tank. Oh well, that reduces the access to the tank and the hood would need to be 18 plus inches high. Rats.
Plan 3, Nothing, nada, zip!
Then, I was reviewing one of Davross threads and came across the answer.
I blatantly grabbed the picture he posted of his build. Most Excellent build!
and cropped it.
and shopped it.
What I plan on is to build an enclosure much like this, put the support tubes inside the enclosure or bolt on to the back. If it works, it will be able to slide it back to front on a mating support mounted on the wall (bolted into the studs).
That would allow me to put all the electrical stuff in the stand. Rats, what about the controller?
If I put the controller in the LED enclosure, I only need to run 4 sets of power to the controller. No long signal lines to get fuzzed. Hummmm.
Oh. You have not seen the controller yet. Well, lets fix that right now. (Build details later...)
Side view 115 mm high x 55mm wide and 85 mm long
Each board will drive 24 LEDs.
4 each 4 channel Power LED shields with the Buck Pucks.
this is from http://www.chestersgarage.com/store/...ed-shield-kit/
1 each Arduino Duemilanove,
1 each Nokia 5110 LED Shield
1 each Prototype shield with the clock, temperature (and the LED control circuit that is no longer needed)
I plan on using the room vacated be the LED control for a fan controller on another shield.
I'm drawing up the plans for the hood and the mounting hardware. I'll build the hood next week if at all possible. The mounting hardware will take a bit longer as I don't have the tools to work with tubing. That needs to be powder coated, etc, etc.
I also will modify the heatsinks a bit. Figure out a connector plan and get more wiring finished.
More about that later as the actual work gets done.
Last edited by Surff; 22-07-10 at 22:43.
The LEDs need a home
So I finally needed to design one and build it.
First, the sketch. This is about the 4th revision...
After I cut the wood, I dry fitted it with tape to make sure that it was going to work. Then, I made the heatsink supports.
I bought some 1/2 x 1/2 x 1/16 inch aluminum angle and cut it to 12 inch lengths (length of the heatsinks). Then on a table saw, I trimmed one side to 3/8 inch so it would not get to close to the Stars. If you are going to do the same, I suggest that you use a 80 or more tooth, thin blade. Set the blade height to just cut through the stock. Place a 1/2 x 3 inch piece of wood inside the angle and use that to hold the work next to the fence and keep your fingers out of the way. Use a push stick to feed the work through the blade.
Then drilled 3 holes on the 1/2 inch side. I set up a jig on a drill press so I could drill the holes in the same place on all the angles.
Then I removed all the machining burrs with a file and sandpaper and cleaned them with Acetone.
(Do this outside and wear gloves). Then I cleaned the long edges of the heatsinks the same way.
Now, look around for your coral glue. If it's a Ethyl Cyanoacrylate gel based product, your good to go. If not, get a new tube of Ethyl Cyanoacrylate gel. The stuff I use is distributed by bSi called IC-Gel.
Take a cleaned panel and place the long edge next to a stable vertical surface
Run a thin line of the gel down the center of the 3/8 inch leg.
Place the angle against the vertical surface and slide it down until in comes in contact with the heatsink while maintaining pressure to keep the heatsink next to the vertical surface.
Slide the angle back and forth a tiny bit. Center it on the heatsink. Place your fingers on angle and press it down on the heatsink. Slide your fingers back and forth to distribute the glue. Hold for about 30 seconds. MAKE sure that the edge of the angle is flush with the edge of the heatsink!
If you glue you finger(s) to the heatsink, DO NOT PULL them off. Peel, Don't pull! Use the acetone to help release the bond. Wash your hands and apply hand cream when finished.
Take the heatsinks and position them on the front or back pieces. The 90 you glued to the heatsink is positioned at the upper edge of the slot. After you get them positioned, mark all the holes with a pencil. If you made and used a jig to drill the holes in the angles, you can transfer the hole locations with a square. If not, drill you pilot holes and mount the heatsinks. Carefully turn the assembly over and place it on top of the other board. Adjust and mark the hole locations. Drill the pilot holes. Hint: Prior to mounting the heatsinks, drive the screws you are going to use into the holes. This will make it MUCH easier to mount the panels when the time comes.
I used #8 x 3/8 pan head sheet metal screws (I sure wish the US would convert to metric...). I drilled 3 holes in each bracket. Two will do the trick
As you can see in the picture above, the angles are bonded and the mounting holes have been pilot drilled.
Checking the fit of the panels again
OK, time to glue it up.
The end cap is not glued in. I put wax paper around it so I could glue in a brace.
The idea is that the end cap is attached from the inside. This lets me remove it to slide out the glass for cleaning and access to the panels.
The end pane attachment point
Sanded, stained, waxed with the panels installed
This assembly weighs in at 35 pounds at this point. I expect another 5 pounds or so consisting of the controller, fans, glass, etc.
Now that the hood is 90% complete, I need to see how the Hood Support is coming along.
About a week ago, I made a bunch of sketches, a couple of phone calls and came up with this.
4 each 3/4 inch inside diameter steel tubing
2 each 3/4 inch outside diameter steel tubing bent 90 degrees
2 each wall mounting plate
2 each hood mounting plate
4 each ball lock pins, 1/4 inch diameter x 1 inch long or nuts and bolts
1 each Starphire glass LED cover 8 7/8 x 51 7/8 x 1/4
Clamp the inner and outer tube together and drill 1/4 inch holes through to allow for adjustment.
McMaster-Carr - Aluminum Ball Lock Pins
The next thing on the agenda is the wiring from the panels to the controller.
oh my god... i wish i really could create something like you are doing for my 2ft cube...
what an achievement..! well done mate...