LED Resin Cube V3

86K95857

Intro: LED Resin Cube V3

Make a resin cube out of an LED light bulb and a few other bits and pieces.


Each time I have make one of these I always think – this could be better.  The first 2 versions which can be found here and here, worked out ok but I have discovered that batteries don’t like to be enclosed and that their fail rate goes up dramatically when they are.  This is due to the fact the batteries need to breath and once encased in resin suffer a slow death.  I can still charge up the original ones but the batteries only last for a couple hours.

So I was thinking the best way to fix this would be to remove the batteries altogether.  I did toy with super caps but a quick search on the net show they wouldn't be suitable for the job.  Caps release their energy quickly and this just won’t work on something like this.

I finally decided to go down the path of using a wireless charging module.  These are really easy to use and work like a charm.  I used one in version 2 to charge the batteries up. 

The other really cool thing about this version is the LED light.  It comes with a remote and has heaps of features which allows you to change the colour and display of the LED's.

The project itself is quite simple and the only real messing about is making the box that the cube sits on.  But you could easily simplify this and just use a brought box of your choice.

Video below.


You can also click "here" to watch the video
and here's how you make one...

STEP 1: Bits and Tools


Things to gather:
1. LED Globe – eBay
2. Heat-sink – eBay
3. Wireless charging module – here
4. Small nut
5. Clear casting resin – I got mine from my local hardware store and it's called "diggers clear casting resin"
6.  Female power adapter - Local electronics store.  I didn't use this one but it would work fine - eBay
7.  3 way switch - eBay
8.  Wood to make the base.  I used some thin ply board and 10mm by 50mm lengths of hardwood.
9.  9v battery clip - eBay


Tools:
1. Soldering Iron
2. Super glue
3. Screwdriver etc
4. Wire cutters

STEP 2: Pulling Things Apart

First things first – start pulling apart the light and heat-sink,

Steps:

1. Remove the fan from the heat-sink.

2. Un-screw the bottom of the light bulb.  The red and black wires sticking out are from the circuit board and should have broken off from the bottom of the globe once you un-screwed it. 

3. Use a screwdriver to pop open the top of the globe.

4. Un-screw the circuit board from the globe.

STEP 3: Re-asssembling

Now it’s time to stick everything together.

Steps:

1. First glue down the small circuit board that comes with the wireless charger, to the inside of the heat-sink.

2. Next de-solder the red and black wires from the LED circuit board.

3. Thread the red and black wires from the charger through the hole in the centre of the LED circuit board and solder into place.

4. Glue a nut in the centre of the heat-sink.  This will act as a heat-sink itself and will prevent the LED circuit board moving too far inside the heat-sink.  What’s really cool is the hole in the heat-sink where the fan went is a perfect fit for the LED’s.  If you wanted to, you could have the LED circuit sitting right down into the heat-sink.

5. Glue the copper coil from the charger to the bottom of the heat-sink.

6.  Test

Note - Initially I was going to have the charging circuit board stuck to the bottom of the heat-sink.  you can see in one of the photos a holed drilled into the middle of the heat-sink and the wires from the charger sticking through the screw holes.  I decided not to go down this option as it looks a little untidy.  

STEP 4: Adding the Resin

Now comes the resin.  I gave a detailed run though on how to use resin in my first version of the LED cube which can be found here.

I decided to make my own mold this time as it's very hard to find one with sharp 90 degree corners.

Steps.

1.  Make your mold.  I used core flute which is the material that is used to make temporary signs.  It can be purchased at most art shops or you can just use an old sign!)

2.  Measure out how big you want the mold.  mine is about 15mm larger than the heat-sink.

3.  For the walls all you need to do is measure a long piece and lightly score 4 times the width you want the cube.  Use hot glue to stick to a base and the wall together.  Be liberal with the glue - it's better to go overboard then have leaks!

NOTE: Core flute has channels all the way through it.  I would suggest using some blue tac or clay to block up the holes where the walls are joined to the base.  I lost a lot of resin because it seeped up the channels.

4.  pour a little resin on the bottom and position the heat-sink in the middle. 

4.  Pour the rest of the resin and leave for 12 hours.  The best hint I can give you when using resin is don't go overboard with the catalyst.  If you add too much the resin will heat up and crack, believe me - I know. 




STEP 5: Smoothing Out the Resin

Steps:

1.  If you used core flute as the mold you will notice the resin has lines running down it.  You will need to get some 400 sandpaper and start sanding.  You could use a rougher grit paper but you might put some deep lines into the resin.

2.  Once you have all the sides smooth it's time to use a 600 grit sandpaper and get rid of the scratches.  Once this has been done move onto a 1200 grit paper to create the final finish.  

Note :I left the cube translucent as I wanted the LED light to be diffused.  You can polish the resin even further so it is clear like water but the LED's won't be diffused.

.

STEP 6: Making the Base

Next step is to make a base for the cube to sit in.    I decided to make my own but you could just use a wooden box and modify if you wanted to.

Steps:
1.  Cut 4 pieces of wood to make the sides of the box and glue together.

2.  Next work out where to want to add the switch and female power adapter and cut some grooves into the box to accommodate them.

3.  Next cut some thin ply board for the sides, base and top and glue to the box sides.  You will need to do the usual measurements and sanding to get all of the dimensions right.

4.  Drill some holes where the grooves are in the box and add the switch and adapter.







STEP 7: Electronics

So now for the electronics.  Initially I was just going to add a 9v battery and be done with it.  I decided to add an AC adapter as well as the 9v battery doesn't last too long.

I have added a diagram which shows how I wired everything up.  It's pretty straight forward so I won't drill down too much on what to do.  Just remember to test out your AC adapter before you wire everything up to ensure the polarities are correct.  I used 9v 1A adapter which I had to drop down the amperage with a resister.  The most that the wireless charger can take is 600ma and I dropped it down to 500ma just to be safe. 

STEP 8: Painting

Once you have everything wired up correctly it's time to stain and varnish your box.  At this stage you can also secure the coil to the lid of the box.  I wanted to have the coil on the bottom of the lid but it just doesn't add enough power to the cube so I had to add it to the top.

Steps:
1.  Use a stain and rub it onto the box.  I only did 1 coat but it's up to you want stain to use.  

2.  Next I used a lacquer to give the box a shine and added about 3 coats.  Don''t forget to lightly sand the first coat.

3.   Once dry you need to drill a couple of holes into the lid.  This is where the coil wires will go through.  De-solder the coil from the yellow box it is joined to and thread through the holes in the lid.  Re-solder and hot glue the yellow box to the side of the wooden box.

4.  Before you super glue down the coil to the top of the lid, test with the cube and work out the best spot for it to go.

5.  Lastly I added 4 pads on each corner of the lid so the cube would sit straight.  I used a hot glue stick and just cut 4 small slices.

6.  Test.

STEP 9: Finished.

If everything went right you should have a sweet looking lamp.  The LED's which are actually SMD's, are super bright and really thrown off some impressive light.

Afterthoughts:
I don't really think that you have to use the charging coil if you didn't want to.  You could use a couple of copper pads which would need to be flat on the bottom of the resin.  When the resin is hard you could sand until the pads are relieved.  Then it would be just a matter of adding a couple more pads onto the lid of the box and your done.

Also, you could just have a couple of wires coming straight out of the resin and join this up to the battery etc outside the resin.  It would mean that you couldn't remove the resin cube but It wouldn't really matter.  It would also make things a hell lot easier.

If you decide to make one of these, post an image of it on the comments.  I'd love to see what everyone else could do with this.

Cheers,
Lonesoulsurfer

50 Comments

Very pretty, well done!

Cheers. Thinking I might re-visit soon and do another version :)

You mentioned that you don't encapsulate the batteries because they have no room to vent. I have a suggestion for you. Use LiFePO4 batteries (Lithium IRON or LIFE batteries for sort). As I understand it they only vent under the most extreme conditions which you project would never hit (good ones can charge and discharge in 5 minutes, under those kind of conditions they would vent). Also you could put the batteries inside a sealed box held in place with foam. In this way even if they vented a little they would be venting into a area that had some space to vent to. In this way you could keep the batteries inside the cube. I have been learning alot by watching your process and can't wait to attempt a wireless charging version with multicolor remote controled bulb using LIFE batteries.

Man - great idea! just been reading about LIFE batteries and they look like they would solve the venting issue.

Let me know how you get on with using the batteries.

This is AWESOME. I'm planning on doing this version as my own personal Jedi Holocron! Got a question though: The link you posted for the LED globe navigates to a different bulb than whats pictured. You reference a b22 but is that the screw in type you have pictured?

ahh much improved mold. Better than the OJ or milk carton.

I've been following all the versions you've done and keep thinking how I'll do it. I think I decided to put rainbowduino in the box underneath and have a solid resin cube on the top. I have no idea if it will glow as well but am going for a translucent not clear cube. (which is also easier to make based from what I got from your earlier versions)

If I actually end up making an instructable ill sure link to yours for the inspiration.

A.I.M. and the Red Skull would like to have a word with you ab out the Cosmic Cube you have stolen.....
About how much was the total cost?
It was probably around $40 to make. The resin is the most expensive part of it.
I will bet that too resin is expensive
yes, that's what it means. Eg. if you look at the bottom of your electric toothbrush (assuming you use one ;) ) you'll notice there are no contacts for charging it in the dock. The power to recharge 'em is "transmitted" just like FM radio.
"Caps release their energy quickly and this just won’t work on something like this." To a direct short or very low resistance load, sure, but like all power supplies (batteries, transformers etc.) they will NOT release all their energy any faster than it is drawn by the device they're powering. I don't see why supercaps couldn't work in this.
Now that I think of it,
It might be good to test for the best method of gluing the film to the mold wall. it's possible that glue dots on the edges will do just as well. (The weight of the resin is probably sufficient to keep the film flat even when the resin gets hot).
lonesoulsurfer,
thanks! one thing I forgot to mention about using transparency film as a mold-liner: Before applying to the mold walls, look at the film...theres a shiny side and a frosted side. The shiny side will make contact with the resin. Also, make sure the entire surface of the film is glued (with spray glue) to each wall of the mold or the catalytic heat (might?) cause it to ripple.
Nice project!

Would the cheap weather resistant 12v LED strips work instead of sacrificing the light bulb?
The globes are only $9.50 on eBay so it's not too much of a sacrifice. You could though use LED strip if you wanted to though.
Have you ever tried to cast this with a small amount of glitter mixed it? Mat have a nice effect. :)
More Comments