I managed to make this costume in about a month, by putting off homework and spending every spare minute of my time on it. Spent maybe $30 total? I had a lot of the stuff beforehand: blankets, T-shirts, clay, boots, etc.

Apologies for lumping all this stuff into one HUGE instructable. And apologies for any blurry pictures, too. :)

Anyway, I love the Hobbit movie trilogy (and love the book as well). Still a bit heartbroken over The Battle of the Five Armies. No spoilers, though. But you should definitely watch it if you haven't already. :)

I made this costume myself, with lots of help from my family. I wore it trick-or-treating: unfortunately, no one recognized me, so I couldn't barrel into their houses uninvited (like the dwarves in The Hobbit did) without being weird. Oh, well.

This costume is really heavy and hot. You will feel tons and tons of sympathy for the poor dwarven actors in The Hobbit. Especially Bombur. Poor Bombur.

My costume isn't totally accurate... for example, I made the coat soft and fluffy instead of leathery, and the brown trim on the coat isn't even fake fur, much less real fur. Most notably, Thorin doesn't wear jeans. Also, I kind of ran out of time, so I had to skip a bunch of stuff.

I made all the 3D models in this Instructable myself, using Tinkercad. :D

Anyway, there's a separate materials list for each step of the Instructable, in case, say, you only want to make the scalemail shirt.

Thorin's full costume consists of:

long-sleeve gray shirt
scalemail shirt (step 1)
surcoat (step 2)
fur coat (step 3)

arm bracers (step 5)
dark-colored pants
sword (step 6)

I ran out of time on these:

belt & belt buckle (step 7)
boots with toe caps (step 8)
jewelry: Erebor key and rings (step 9, 10)

Have fun! Post pictures if you make this costume! :)

And by the way, the pictures of Thorin himself weren't taken by me personally, so... yeah.

Step 1: Scalemail

Materials:

3D printer (optional)
Wax paper (optional)
Air-dry clay
Dark blue T-shirt
Strong fabric glue
X-acto knife
Blunt knife
Metallic silver spray paint

I designed & 3D printed some molds on Tinkercad: Rhombus Scale Mold & Hexagon Scale Mold.

And here's the overall design of the armor: Scalemail. I took off a few rows of scales so the model wouldn't take a couple years to load. :P I ended up not using this design anyway, it would've taken too long to make each unique scale.

If you don't have a 3D printer, sculpt a scale with clay. Let it dry. Press it into a small slab of clay. Let that dry. Voila, there's your mold.

Anyway, press air-dry clay into your mold. You'l need about 90 hexagons and 100 rhombi, give or take 20 scales depending on your size. It will take maybe 5 hours total, so don't take out all the clay at once or it'll dry.

It helps to put your scales on wax paper to dry. That way they won't stick to your table. While they're drying, notch the edges with a blunt knife.

(To get triangle scales, slice some rhombus scales in half.)

Once the scales are dry, take them outside. Lay them out on a cardboard box or something, then spray-paint them silver. Remember not to do this inside unless you're in a well-ventilated area, have a respirator, etc. It's easier and less messy to do it outside, anyway.

Give the scales plenty of time (at least a couple of hours) to dry outside. Then bring them inside. Lay your dark blue T-shirt flat on a table or floor. Lay out scales on the front of the T-shirt according to a picture of Thorin's scalemail.

(Tips: If your scales are kind of thick, you should do the sleeves FIRST before doing the front of the shirt. Also, when gluing down scales, try to put the glue in the center, instead of gluing down the edges of the scales. The shirt will be more flexible that way.)

Using the fabric glue, glue the scales to the front of the shirt. Let dry for about 12 hours, depending on what type of fabric glue you're using.

Fold the sleeves so they lie flat on the shirt. Lay out the scales; glue the scales down. Let the sleeves dry.

Try the scalemail on. See if the scales on the sleeves look all right. Take the scalemail off and add scales to the sides of the sleeves or the top of the sleeve as necessary.

Then you're done! Don't wash scalemail in the washing machine; the clay might crack (or soften into sludge, depending on what type of clay you used).

Step 2: Surcoat

Materials:

Dark blue fabric
Dark blue thread
Needle
Sewing machine (optional)
Scissors

Fold the ends of the fabric in towards the center. Cut arm-holes. Sew the edges so they don't fray too much. Sew the tops of the shoulders.

That was easy, right?

Step 3: Fur Coat

Over the surcoat goes the fur coat. Or you could call it the overcoat, but that doesn't have the same ring to it. :P

The fur coat is definitely the most challenging part of the costume.

Materials:

Dark blue blanket
Furry tan-colored blanket
Needle
Scissors
Dark blue thread
Sewing machine (optional)

Okay, Thorin's coat is actually made from a gray-ish leather, but... well... blankets are much softer. And fluffier. Also, Thorin's coat actually uses fur and not, well, soft and fluffy blankets. It's close enough, anyway.

Lay the blankets out on the floor. Slice them in half height-wise: you should have a dark blue piece of fabric, a white piece of fabric (underside of the dark blue blanket, color really doesn't matter), a furry piece of fabric, and a brown piece of fabric (underside of the furry blanket).

Cut out a roughly coat-shaped pattern on the dark blue fabric. (Sorry for the lack of details, I honestly had no idea what I was doing.) Cut out another coat-shaped pattern and slice it in half for the coat opening.

Make sure the coat is long enough. Short coats aren't as #majestic.

Cut out matching coat patterns from the brown fabric (underside of the fur). Sew them to the dark blue coat pieces. The brown will be the inside of the coat. For a lighter and less heavy coat, skip this step.

Sew the sides of the coat together. Leave holes for your arms. Sew the tops of the shoulders together. Leave a hole for your head.

Try the coat on. Adjust the length, re-sew things as necessary.

Fold the coat opening and sew it down so it looks nicer. Sorry, I don't really know how to explain this bit.

Using the white fabric (underside of blue, color won't matter), cut out prototype thingies for Thorin's fur collar. Put on the coat and lay the prototype thingies on top. Adjust as necessary. Don't forget that the collar extends around the back of the coat.

If all looks nice, lay the prototype thingies over the fur blanket. Cut the fur into those shapes. Sew the prototype thingies and the fur shapes together. You could stuff them so you have a really, really fluffy collar, but that costume will be really, really heavy and really, really hot.

Stitch the collar to the coat. This is the most difficult part of the costume, so be patient.

Cut out long strips of fur fabric. Sew them to the coat's edges to line it.

Finally, fix anything that looks excessively weird.

And you're done! You can add buttons or clasps to the coat to close it if you want.

Step 4: Fingerless Mitten Thingies

Materials:

Fur from blanket
Needle
Thread
Sewing machine (optional)
Scissors

Cut fur into 2 thick strips, long enough to wrap once around your hand.

Cut a hole for your thumb, stitch the ends of the strip together. Repeat for the other mitten. Fingerless mitten thingies aren't part of Thorin's actual costume, but they're warm & useful if you have extra fur from the fur coat. Not that you'll need extra warmth while wearing the full costume...

Step 5: Arm Bracers

Sorry if the pictures look a bit weird: it's hard to twist your arm around and take pictures of it.

Materials:

4 sheets of brown craft foam (9"x12")
Wood stain & sealant
Scissors
Hot-glue gun & refills
Hair dryer (optional)

Refer to a picture of Thorin's bracers and cut the basic shape out. I made 3 separate craft-foam layers for each bracer: the innermost goes over the hand, the next layer helps you "close" the arm bracer around your arm, the outermost is the actual "bracer" thingy.

Optional step: Bend the craft-foam so it's more circular and less flat. Blast it with hot air from the hair dryer for a couple minutes. The bracer should, kind of, keep that shape.

Cut the rest of your craft foam into long strips. Referring to the picture, cut the strips into pieces and lay them out on top of the bracers in their pattern. Hot-glue the strips to the bracers.

Hot-glue strips of Velcro to the craft foam. Try the bracers on and trim the Velcro, but don't cut too much off.

Paint the bracers with dark wood stain; use some sort of sealant on top of that. I used polyurethane.

Give it plenty of time to dry. And voila!

Step 6: Orcrist

Here's my Instructable $2 Realistic Sturdy Blunt Swords in 10 minutes. Specifically, here's how to do Orcrist.

(Basically, hot-glue some foam to a yardstick. Trim the foam. Put silver metallic duct tape on top. Wrap hilt with fake leather, though the real sword doesn't have leather. Done.)

Step 7: Belt & Buckle

I actually ran out of time on this, but anyway.

Materials:

Belt
Gems
3D printer or air-dry clay
Strong fabric glue

Option 1: Sculpt clay into a belt buckle.

Option 2: 3D print it: Belt Buckle

Glue sparkly jewels to the buckle. Glue the buckle to the belt. Done.

Step 8: Boots

I ran out of time on this, too.

Materials:

Boots
Air-dry clay
Wood stain & sealant
Fur from blanket
Index cards
Tape
Velcro (optional)

Cut strips of fur, sew the fur to the boots. Or attach Velcro to both, so your boots can be normal by day, but dwarven boots by night. :D

Make models of the toe caps out of index cards and tape; check to see they'll fit your boots.

Make toe caps, based on your paper models, out of clay. Make trapezoid things first, then layer strips of clay on top to create the design.

Paint with wood stain. Seal.

That's it!

Step 9: Jewelry

Materials:

3D printer
Air-dry clay (optional)
Hot-glue (optional)

Key to Erebor. I printed it in Polished Gold Steel from Shapeways. Wore it on a chain as a necklace. Okay, I know it's not actually gold in the movies... well, let's call it improvised symbolism. And it's prettier.

Thorin's Ring. I sent the parts separately to Shapeways, hot-glued the parts together, and added some more hot-glue for a snug fit.

Smaug ring, just for fun. (If your printer is big enough, this could be a bracelet instead.) I printed it with my own 3D printer and just colored it blue with some markers I had nearby. I know, I know: Smaug's darkish red in the movies. But my red marker was out of ink, so I had to use blue. Also, I know that Thorin would never actually wear a dragon ring. *evil laughter*

I didn't include Thorin's other left-hand ring, but it should be pretty easy to make out of clay.

As a side note: I was going to sell these models on Shapeways, but wasn't really sure about copyright issues so I decided not to. So, enjoy! :)