If you want to go big with a costume and create something people will remember, you can’t lose with Transformers. Instructables user thomp5km, a.k.a. Kaleena, decided to build a Grimlock costume from Transformers: Age of Extinction for just that reason. She was inspired to do so by her time spent working at Disney World and seeing how costumes made guests happy.
Kaleena planned to have Grimlock ready for Halloween, but the build process took longer than she thought it would. She spent about two months creating the costume, and it was completely handmade. She didn’t use any templates or pepakura files for the armor, and she’s happy with the finished product. With height extenders and the spike on the helmet, she ended up being seven feet tall.
After casting her torso with duct tape, she turned to a detailed model of Grimlock for inspiration. She used EVA foam mats and rolls to make all of the armor after first drawing templates from poster board. She explains:
Starting off with the references, I made a template of how I wanted each piece of armor to look, and literally built the armor out of poster board! This is such an important step is it helps cut down on trial and error with real foam, which would be expensive, whereas poster board is cheap and okay to destroy and start over! After building and rebuilding, making sure the armor looked good and functioned (the hardest part) I would then trace it onto the thick or thin foam mats and cut it with an exacto knife. MAKE SURE the exacto blade is sharp, or you will cut into the foam and it will be rough and jagged and almost impossible to fix! I went through several blades throughout this project. Once you have your forms cut out, take a heat gun and evenly heat both the front and back sides of the foam. You will see the difference when the foam is heated because it will have a shiny darker texture. Once evenly heated it is ready for forming!
Take your pieces and from the back of the foam heat the piece until the foam is really hot but NOT burnt. If you burn foam it smells and turns deep black and is not as easy to form, or pretty! SO catch it right before that point. Once hot enough bend and shape your foam to the desired form and hold it there until it has cooled down. You may have to do this several times to get the shape just right.
Get all the details about the build at Instructables.