This is my entry into the ShopBot Challenge and the Make it Real contest. If you like it, please rate highly and vote in both contests! With a ShopBot Router and a 3d printer in my shop, I could build more crazy items (more robots and costumes). Also, I am a member of a Nashville robotics club which could make use of the CNC router for various projects.
For scale, the room in the picture is 25' x 25'! This is a HUGE costume. Look for this costume at Dragon*con in Atlanta 2012!
Step 1: Design
I wanted to build a large-scale dinosaur costume that would standout. First, I found several 3-D dinosaur puzzles on the internet. Once I found one to my liking (look, geometry, etc), we scanned the parts into a design software (can be anything as long as you can output a .dwg file for the machine shop later). Once scanned, the parts were output onto heavy card stock and constructed into a prototype model. From there, you have to figure out what parts are going to move, where you will be within the structure, and how you will hold it up.
Since most of the models are designed to be static with no moving parts, it takes several revisions to the parts to make mounting plates, get rid of parts that impede movement of parts, etc.
Note - Take note of the slots that plug into each other. They need to allow for the thickness of your foam material (sometimes several layers)
Once you get this all done, the parts will be ready to be cut by the CNC router (a spinning tool that is computer driven that can cut out exact parts from large sheets). The machine shop will "nest" the parts (get as many parts onto a sheet as possible which saves waste and $$).
You could cut these out by hand, but that would take FOREVER. Best to use a CNC Router for this!
Step 2: Cutting Parts
Once the design is finalized and you have your machine file (check with your machine shop for type of files that may be used). It's time to get the foam. I used 1/2" thick white closed cell poly foam plank. This stuff came in 4' x 8' sheets and this project took about five of them. I paid around $150 for the foam and another $100 for shipping (ships flat in huge box via truck).
Once I got the foam delivered to the machine shop, we were ready to cut! The CNC router cuts this stuff like butter as long as you cut around the part in a counterclockwise method (same with the hand routers). Below is a pic of the first batch of cutout parts.
I am sure if you are a glutton for punishment, you could cut all this out by hand, but it would take a LONG time and your tolerances would be off. This is the beauty of the CNC Routers!
Step 3: Structure
You will notice that the foam parts are quite limp without any structure and won't support their own weight. You have to build a skeleton for the skeleton ;)
I used 1/4" thick steel rod for most parts and 1/8" for the smaller parts that weren't load bearing. For this step you need a welder, a vice to bend the rod, and a method of cutting it.
As you can see from the pics, the steel rod was shaped to match the part, a groove is made part way through the foam piece to house the steel rod, then an overlay part glues over it to hold/hide the steel. To cut the grooves, I used a router on the larger ones and a dremel router on the small ones. You could also make the grooves part of your file for the CNC router.
For some overlay parts, I used 1/8" thick white abs plastic. For others, I used 1/2" foam to cover up the steel structure. You can see examples in the pics of different structural parts. Every dinosaur is different, so different pieces will need to be reinforced, but the methodology is the same. For extra heavy parts (like the neck that supports the ribs, arms, and head) I doubled up the 1/4" rod to make a structural beam. This still allows some movement, but supports the weight nicely.
NOTE - Superglue (cyanoacrylate) is the ONLY glue that will adhere this closed cell poly foam!
Step 4: Supporting Rig
As your pieces start to slowly come together, you will next be faced with the challenge of how to support/wear the costume.
I aquired a used military surplus backpack that was then modified. As most of the weight of the dinosaur is over the front, you need to add a belt to the front of the backpack so that the pack is attached around your torso. This allows the weight to ride properly on the waist and shoulder straps.
I used aluminum square tube to create the frame that attaches the dinosaur to the backpack. I fired up the chopsaw and welder to create the parts. After welding, the parts were then taped off and painted either white or black depending on what needs to be seen or disappear.
Note the slanted aluminum plates on each side. This is where the lazy susan bearings plug into that allow the legs to move.
Note - You can weld aluminum with a Mig welder IF you use a teflon gun liner, and an oversized tip. BUT, you MUST use shielding gas or it won't work. Aluminum wire is required.
Step 5: Final Assembly
Now that you have tons of parts, it's time to put them together! LOTS more superglue! Some of the parts that were structural (legs, pelvis) had to be permanently assembled as they were load bearing. The rest of the parts are made to friction fit into the slots. Other than the legs/pelvis, the other parts can pack flat in a large zippered carry bag.
The neck and spine attach via two aluminum angle plates that attach with large bolts and wing nuts. This then attaches to the backpack frame.
Note - Some hardware was fabricated to help take the weight off of certain parts. I used steel fishing leaders to help carry the overhung load that the arms placed onto the rib. The leaders were connected from the rib to the neck.
Step 6: Finishing Touches
This costume plays on the use of light and dark to make certain parts of it "disappear."
For the outfit, I bought a black military surplus flight suit. I also bought black cotton gloves, black socks and shoes, and a black mesh head cover.
Any part that you want to be not noticed, make it black!
Also, to cover up the spine attachment hardware, I created pieces of white foam that velcro over it.
A good project is all about the details!
Step 7: Party Time!
Once I had the crazy big dinosaur costume done, it was time to take it out on the town! Several pics are below.
Note - A costume this large isn't for the faint of heart! You have to think about where you will be able to take it, and how you will transport it, and where you will store it. You will need at least one person to come along to help you assemble it and guide/protect you if in a crowded place.
This costume will be worn at Dragon*con 2012 if you would like a closer look!
This is my entry into the Instructables ShopBot Challenge and the Make it Real contest. If you like it, please rate it highly and vote for it in both contests! I have several other large scale costumes in mind (aeronautical themed) as well as some new robots I would like to build. With a ShopBot and a 3d printer in my shop, I could make some CRAZY stuff! ;)