Instructables
This is a hand made 10x scale model of a 10mm LED that gives off light via 3 one watt LEDs inside a custom made resin cast (made by me) that also has a Pulse Width Modulation (PWM) light dimmer. To set the cast I first had to create a wooden form of an LED and slather silicone on to create a mold so that I could pour resin into it.

If you have any improvements that you like to be made note of, please leave a comment!

This is part of the Craftman contest, so if you liked this instructable, please vote for me between january fifth and eleventh by hitting the vote button in between those dates (a vote is different than a rating, but ratings are welcome too ;) )

I give you one of the world's largest, DIY LED.
 
Remove these adsRemove these ads by Signing Up

Step 1: Table of Contents

Picture of Table of Contents
This is a somewhat complex instructable involving the following skills:
--soldering/electronic knowledge (Must know how to read schematic, but if you cannot, please ask questions by leaving a comment)
--Wood work (need to be able to use the following: lathe, coping saw, various sanders, drills, etc)
--Resin Casting (This was my first real time casting anything, so don't worry about it)

I have broken this instructable up into the following:

--Forming the Wooden LED: steps 2-10

--Making a Mold of the Wooden LED: steps 11-12

--Electronics: steps 13-16

--Casting the LED: steps 17-20

--Finishing Up: steps 21-23

Step 2: Materials for the Wooden LED

For forming the "head" (The epoxy part of a normal LED, the thing that kind of looks like a bell) of the LED you need:

TOOLS:
Lathe
various lathe tools
Coping Saw
Vibrating Sander
Belt Sander
Clamps
Chisel (or some tool to scrape off glue)
Radial Arm Saw (or some other way of cutting up the pine board)
Putty Knife (optional, but nice)

MATERIALS
1" x 6" x 8' piece of pine
Wood Glue
Paper
Paper towels


Safety
Safety Glasses (necessary), ear protection (highly recommended), Respirator (highly recommended, especially while sanding)

Step 4: Glue the Wood

Now that the wood is cut into 8" segments, we must glue them together into a ~5.5"x5.5"x8" block of wood that can be turned down on the lathe.

Spread a thin layer (don't just slather it on thickly!) of glue on both sides of each sawdust-free (this is important) board and clamp them together. Have a dry run before you glue the wood, put the worst pieces of wood either in the middle or on the outside (middle so it's hidden, outside so that it'll be turned down into sawdust). Put down paper so you won't get glue on your clamps and/or workspace.

Also, all wood is warped, since all of these segments are from the same board they should all bow the same way. Make note of this while clamping, have all of the pieces of wood bow the same way so that there will be a smaller gap in between segments, thus creating a stronger, cleaner joint.

Once the Glue is dry, scrape off as much excess glue as possible; the glue is harder than the wood and will dull your lathe tools faster.

Step 5: Mount it on the lathe

From this point on I will be using millimeters and centimeters as my main unit of measure because LEDs are metric, and so will this one. I only used Imperial units before because that's what all of the wood in the US works off of.

If this is your first time using a lathe, you should probably read a tutorial somewhere; I believe the lathe is a very safe tool, but can turn very deadly if you don't know what you are doing.

Draw an X on each end of the block of wood to find a crude center.

This Block of wood was too big for my lathe, so I (well, my dad) had to cut off some of the corners (wood that would have been turned down anyways, I didn't take off any useful wood).

Step 6: Turn it Down

Picture of Turn it Down
Using the Gouge, turn the block of wood into a cylinder. Then use the flat tool (along with the gouge) to make a uniform cylinder that has a diameter of 11cm. If you don't have a caliper, you can use a c clamp with a ruler (that's what I used).

Once turned down, take your ruler and mark off a 14cm section; this will be the overall length of the LED. From the left of that section, mark off 2cm and 10cm.

See picture for what each part is for.

Step 7: Carve it into an LED

100_4816.JPG
100_4817.JPG
First off, do not turn down the 2cm section, this is the lip and it's diameter is 11cm, which the cylinder already is. Using a gouge, bring down the excesses to the smallest diameter that your lathe can handle/you are comfortable with. Next bring down the biggest section to a constant 10cm. Bring down the last, right most section (besides the excess) to 10cm and round it off starting from the end of the 10cm constant and the left mark of the excess. If you are confused, please consult the picture.

When you're done sand it down with some fine grit sandpaper and put some finishing wax on, I'm not sure if it's necessary, I just did.

Step 8: Cut and Sand the Nubs

I don't know about most modern lathes, but mine leaves little nubs I have to cut off. Normally I'd do this on my bandsaw, but the LED was too big for it, so I had to use a coping saw. Cut them off as close to the LED as possible. for the nub by the curved down part, using a vibrating sander. For the nub at the base, use a belt sander.

Apply more wax to the newly sanded parts.

Step 9: Find the Center and Drill

Picture of Find the Center and Drill
100_4886.JPG
Now that you've cut and sanded down the nubs, you have a wooden version of the LED head!

Now we have to find the center so that we can drill 2 holes equidistant to it for the legs of the LED. This is probably not too necessary (because you won't be covering the base in silicone later, unlike me). Instead of following steps 9 and 10 you could just drill a hole in the vague center and insert a dowel rod (to give it support while creating the mold)

To find the center of a circle you need a ruler and a right triangle. Draw a random triangle into the base of the led and find the center of each line. Using the right triangle, draw a line that is the perpendicular bisector of each of the triangle's sides. They should all converge to a central point which is the center of the circumscribed circle, the LED. Geometry class actually helped in a real life situation! Who would have thought?

Now that you have found the center, draw in the diameter. Drill 2 (5/16) holes along the diameter, each 1.5cm away from the center.

Step 10: Create LED legs/support

Cut 4 pieces of tube. to find the length, take 30cm and add however many cm that the tube can go into your base (these pieces of aluminum tubing are going to become the leads of the LED). In my case, their length was 32cm.

Using super glue (or any other good strong glue), glue the tubes into the wooded LED.


You are now done with all of the wood work, yay!

Step 11: Making the Mold

Picture of Making the Mold
100_4897.JPG
100_4900.JPG
100_4903.JPG
Since I had to make the Instructable with materials that could be bought from local stores (due to the Craftsman Contest deadline), my materials are less than ideal, but they worked!

Go down to a store such as Home Depot or Lowes (I went to Lowes) and pick up a 4 pack of Silicone Caulk. Along with this you need about 5ml of Glycerol (I had 10mL). Supposedly this makes the Silicon caulk better for making a mold (I found this info here), and I used 2.5ml of glycerin per canister of caulk (about 10.1 fluid ounces).

Make sure you mix the silicone and the glycerin well! Slather it onto the wooden LED. I also sealed the base, but later this only caused more headache, so I recommend not putting any silicone on the bottom. Also, make sure you put enough silicone on the lip (it's easy to only put a thin layer there, which will rip later, like mine did)

I made the complete mold in 2 layers, using 1 can per layer.

WARNING: This stuff smells really, really bad (imagine a vinegar smell that's like 100x more powerful and burns your eyes and throat). Use with proper ventilation.

Step 12: Extracting the Wooden LED

Picture of Extracting the Wooden LED
100_4930.JPG
100_4931.JPG
100_4932.JPG
100_4936.JPG
Taking the LED out should be simple (if you didn't slather silicone along the base, unlike me). While pealing the mold away from the wooden LED you pull it inside out, so you have to flip it outside in.

Step 13: Electronics Parts

Picture of Electronics Parts
Picture 78.jpg
You should have some electronic expiereince, but it's not necessary.

Electrical Components Needed:
(1x) 555 timer
(1x) 0.1uF capacitor (usually ceramic)
(1x) 100k ohm linear potentiometer
(1x) knob for the potentiometer
(1x) 33k ohm resistor
(6x) 10 ohm resistor (1/4 watt or better)
(1x) 3.3k ohm resistor
(1x) 510 ohm resistor
(1x) 0.25 inch knob
(3x) 1 watt white LEDs (usually these come on a star PCB)
(1x) switch (should come with the lamp you are using for a base)
(1x) npn transistor (I used a 2n4401)
(1x) diode (I used a 1n4148)

NOTE: resistor values can be changed, just be relatively close to the values I give (except the 10 ohm resistors, don't use any other values)

Step 14: LED Driver

Picture 80.jpg
Picture 87.jpg
Picture 81.jpg
Picture 82.jpg
Picture 83.jpg
The Driver I created for this LED consists of a current limiting resistor (a couple of series and parallel resistors) and a 555 timer chip pulsing the LEDs at different duty cycles, making it appear lighter or dimmer.

I'm going to assume you know how to solder. If not instructables offers a large array of how-to soldering instructables.

I personally soldered in the air (not using a circuit board/prefboard) simply because I didn't feel like cutting out a prefboard and mapping out where all of the leads go.

Step 15: Mounting the LEDs

100_4879.JPG
100_4888.JPG
Mount the LEDs on a little strip of aluminum with some thermal glue. These LEDs can get fairly hot, and even hotter in solid resin, so we need as much cooling as possible (the heat will be fed along the tubes later), which is probably not enough as I should have. Make sure you orient them in an easy to solder in series format.

I've also included some pictures of 1 (just one!) LED on.

Step 16: Drill and Glue the Tubes

Drill a (1/8) inch hole (maybe a bit bigger, up to you) near the top of each tube, the wire leading to the LEDs are going to pass through these tubes.

When the wire is fed through, using the thermal glue again, glue the tubes to the base of the aluminum that the LEDs are glued to.

I added more glue later because the original amount wasn't enough to keep it sturdy.

Feed one wire through per tube.

Step 17: Materials for casting the LED

--48 fluid ounces of clear resin (If you go to Michaels, this is one big and one small container)
--about 5.6 ml of catalast (or 120 drops, I measured measured how many ml were in 10 drops and I went from there.)
--mixing bucket
--drill and a paddle or just a wooden stirrer (drill is so much easier and faster and safer)
--a way of holding the mold and the LED module

Step 18: Pour the Mold

Put the silicone mold in a beaker or some other apparatus that will keep it upright as the resin is being poured into the mold. Mix 48 fluid ounces of resin with 5.6 ml of catalast. Mix well (this is so much easier with a drill and a mixer, I made one out of a dowel rod glued to a piece of wood). Pour the resin into the mold all the way to the top.

When filled, insert the LED module (being help up by a clamp or tape or anything); make sure everything is straight before you leave it to harden!

NOTE: This stuff smells pretty bad, so work in a well ventelated area (such as a fume hood)

Step 20: Polishing

Picture of Polishing
100_4989.JPG
100_4990.JPG
100_4983.JPG
100_4984.JPG
My cast was anything but perfect; it had bumps, depressions, lines, and everything in between. Using a vibrating sander I started at 180 grit (to get rid of all the big stuff) and gradually worked my way up to 600 grit (I didn't have any higher) and then finished off polishing with a polishing compound and a soft cloth.

Various stages in polishing/sanding. I couldn't get out all of the imperfections...

Step 21: House all of the components

Place the LED driver in the base of the old lamp and instead of having a normal AC chord feeding out, have a wallwart wire feeding into the base (have the wallwart rated at 12 volts and at least 350mA.

Step 22: Insert the LED

Well, how hard could it be? Insert the LED leads into the base and seal with epoxy and/or superglue. Once dry, solder the 2 wires from the LED module onto ground and from the 555 LED driver.

Step 23: You're done!

Picture of You're done!
100_5006.JPG
100_5005.JPG
Your LED lamp is now finished! You can now test out the different brightness settings and the coolness of the lamp!!!!

I would take different birghness pictures, but it doesn't show up that differently on my camera (some sort of auto-brightness changer?)

Have fun with one of the largest DIY LEDs!
cj86758 months ago
NEVER I MEAN NEVER WEAR GLOVES ON A LATHE!!!!!
If the glove got caught in the piece your turning it would snap your wrist and bring your whole arm into the lathe
kris754a1 year ago
try make a 8x8x8 LED cube out of it LOL :-P
hec3172 years ago
Shouldn't one "leg" be smaller than the other?
zack2472 years ago
ooh, i like this.
id do this except with a 0603 style LED just for kicks.
make a giant ir tv remote!!
it's so big
this looks wrong btw
11618582 years ago
you should have a black comfoter and a silver and black alternating bedskirt and it would look like a processor chip
holy crap... plum creek's the tree farm above my property!
sysop2 years ago
Love it!
Simple suggestion: What about making the LED leads/supports using square tube stock instead of the round tubes?
Nice radial arm saw. Is that in your house? also i'm going to assume you didn't have a fume hood in your house as well. But all in all, a very cool project. Just out of curiosity, how heavy is the damn thing?
Monsterguy2 years ago
That's wonderful! :)
ps3king12 years ago
ill buy one, how much?
Next up -- Jumbo sized incandescent bulbs!
randofo2 years ago
Sometimes I feel like I have seen just about every project on this site, but every once and a while I still run into something new from the archives and think "Wow! That is awesome!" This is one of those projects. Nice job. Really digging this.
Wally_Z2 years ago
Could you add a potentiometer or rheostat to change the brightness easier?
chicopluma2 years ago
OMG I knew optimus prime eyes worked with led and here is the proof hahaha
awsome proyect
SHIFT!3 years ago
How come I've never seen this before- this is AWESOME!
jamesorlov3 years ago
it;s great! ))
hintss3 years ago
we should have a giant SMD LED. and a giant arduino.
ElvenChild3 years ago
which end is +
The longer one.
Kryptonite3 years ago
I love the rating this has got.
wobbler3 years ago
A bright idea!
zombiefire3 years ago
ill make a much simpler instructable simular to tis soon
Blackice5043 years ago
This is so cool in a geek way i will build one as well but with some differences but thank you for the idea keep up the great work.
Rimwulf4 years ago
Can't I use casting wax to make the the dye instead of wood?
Highjump444 years ago
 instead of spending so much time and money on the the wooden mold couldn't u just put the resin into a trashcan or a drinking glass, vase ,etc  
Jodex4 years ago
Grreat!
wyzzz4 years ago
you are the real winner, its great.
wyzzz from vienna
I absolutely love it! Fantastic job!!!
NYPA4 years ago
Imagine a light board of these!
moshee4 years ago
you could make it detachable by putting 2 giant breadboard-style holes in the base
Dagon3274 years ago
What about grinding off the lip on one side for the cathode?
That is SOOOOOOOOOOOO cool!
That is pretty impressive. I think I would try sand blasting it to make it evenly mat. Or you could do like they use in industrial plastic manufacturing and dip the thing into acetone. (providing this plastic is sensitive to it) it will make it shiny. ( this is what they use for screwdriver handles at Stanley) Anyway, This is really cool Idea! Congrats...
eng.germano4 years ago
What did you use to fill it? What material?
rpjamess15 years ago
Another way to find center, and easier than using the triangle method, is to take a ruler that goes through a 90 degree angle, place the cylinder (of big LED) into the angle and draw a line. Rotate the cylinder, draw another line. The intersection is the center.
So, what you are saying is, "If you have a neat tool designed to find centres, use that, as it is easier"? It's only easier if you have the specialist tool. Otherwise a regular ruler is much, much easier.
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!