This is for the wired portion of Big Daddy with pictures to show how I created the battery housing and made his light-up helmet with hot glue. The crochet pattern can be found on Ravelry. It would be neat to use this technique in other dolls. I wish I had a 3D printer, it would have made the helmet much faster and easier! Instead, I used lots and lots of hot glue.

Step 1: Creating the Helmet

To create the helmet with port holes I needed to make 8 crochet circles and stitch them all together. I did this by making magic rings and just leaving them open instead of cinching them closed as usual. I also used a tiny hook.

After I had all of the circles sewn together in the right pattern I filled in the gaps with tiny crochet squares. I would make a little 2x2 crochet square and then sew it into place. I needed to make this flat piece a sphere so I began to crochet around the outer edge of the circles chaining between each gap an equal amount. These are my notes for creating the helmet shape.

Helmet
D hook
mr 14 make 8 and sew together

F hook
To create a round shape do the following stitches starting on the right circle of a set of two. 2sc, ch 3, 2sc, 6ch, 2sl st, 6ch, 2sc, 3ch, 2sc, 6ch, 2sl st, 6ch
This will evenly space sc around 42 foundation stitches for a total of 5 rows.

Fill in the holes with 2 (ch3, sc across 2) squares. For the side holes sc along one side between two circles then ch 1 turn and sc. Sew to fill in hole.

Step 2: Hot Glue!

If I had a 3D printer this part would have been a lot better. Since I don't, I winged it at home with some hot glue. You'll need to create the port holes and head portion to diffuse the light through all of the holes.

I made each little port hole first by wrapping a straw in foil to create the shell to fill with hot glue. A hard plastic straw just happened to be the perfect size for the holes. I'd pick something else to make the tubes with next time. Foil was a pain in the butt to pick off the hot glue. I filled each tube with hot glue then lifted up slightly to let some ooze out to create a base to stand. After they cooled I could pick the foil off.

When all of the foil was gone I trimmed them down to about a centimeter tall. Just tall enough to push through the holes of the helmet and be flush with the outside. The base of the tubes keeps them from poking all the way through.

Since it's yarn I needed to line the inside with something to keep the light inside of the head and not shining out everywhere. I chose foil and carefully placed it around each port hole and up the sides. Then I filled the cavity up with hot glue just above the side lights.

Step 3: Add Your LEDs

I bought two VERY bright LEDs from Fry's. One red and one yellow. You can make Big Daddy light up with just one color but the wiring diagram will be for two. If you want only one light it will be a lot less complicated since you will only need an on/off switch.

To diffuse the LEDs you'll need to add another layer of hotglue and then push your LEDs into it side by side pointing towards your portholes and let the hot glue cool before letting go so they stay pointing straight. You can trim the posts if needed. Ignore the wiring in this picture, I was testing and using a toggle switch initially and it was way too large.

Step 4: Battery Housing

A mini M&M tube works perfectly with a 2 AA battery holder. I just had to trim it down to the right size. The end of the tube is the top of his tank and I used the lid of the tube to carve out the switch holes for the bottom of the tank. You'll follow the tank directions except instead of creating a solid tank you'll make 2 open ended tank parts. One long enough for the battery holder and the other only a few rounds for the switch box.

To connect the two I trimmed a brown zipper down and sewed it in by hand. I attached the tank halves together with matching brown yarn in the back. The sewn zipper will hide under the M&M tube and the switch box to give it a polished look. You won't want to secure the tube until you have the wiring completed, but in the end I put a few dots of hot glue to keep the tube in place. Leave the tube out for now.

Step 5: Covering the Tank

I made the valve with wire.

Create 4 Ls with wire and hot glue the Ls to the top of your M&M tube.
Slide this into your crochet tank and poke the wires through the top of the crochet.
Wrap the base with gray yarn for about a centimeter then bend the wires down tightly against the yarn.
Wrap each leg with gray yarn.
Create a circle of wire and wrap this with red yarn.
Place the red circle ontop of the wires and bend the wires where they will meet the red.
Trim the wires to about 2 inches so they are easier to work with and poke them through the yarn of the red valve and wrap them around once to secure the silver bars to the valve.

Step 6: Wiring Diagram

You'll follow this wiring diagram to create the switch box (and the rest of the doll). You won't be able to mess with this later so I'll put this here to get the switch part done.

I carefully cut out the holes for the switches from the lid of the M&M tube. You'll need a SPST rocker switch and a SPDT slide switch. The rocker will be for on/off and the slide will change the lights between red/yellow.

I cut a small hole to run the wires out, too. This little pod will fit in the bottom of the tank. I cut a section of the tube out and created the bottom by filling it carefully with hot glue. You'll need to block off your switches so hot glue doesn't get inside of them. Hot glue will protect everything from getting bumped while in the tank.

Step 7: Location of Components

Here my husband demonstrates the lights changing between yellow and red. Again ignore the wiring, this was during testing and using the too-bulky switch.

The wires for the battery will go down and out of a hole in the back of the tank. You will need to create this hole in the plastic before you place the plastic tube inside of the crochet.

The wires from the switch box will also go up the tank and out of the same hole.

When you have the whole doll made and wires attached to the LEDs from the helmet you'll feed the LED wires through the body and out of the back where the tank wires will meet them. You'll solder them together on the back side, tape them, and poke all of the wire back into the body.

Step 8: Crochet Big Daddy!

More pictures of him are here.
You can find a lot of my progress on my Facebook page Nichole's Nerdy Knots. He was an interesting experience! My first time soldering.