EVA-foam Lego Nexo Knight costume

Our kids are huge fans of the Lego Nexo Knights franchise. As most of my experiments, this one started by seeing a youtube video that got me interested. Combining the cosplay methods and my kids’ enthusiasm for Lego’s I decided to make them a EVA-foam Lego Nexo Knight costume.

EVA, or Ethylene-vinyl-acetate is a type of plastic, that is easily malleable, cheap, light and holds its shape nicely. It has been a goto material for a bunch of cosplay fanatics and they’ve created a lot of amazing stuff (here, here, and here to name a few) from the material. It’s a very common sight at indoor play parks and gyms as flooring material. It’s actually even sold as “gym mats” in various stores.

So the project started of with sourcing the material. I only found brightly coloured stuff, as the cheaper (and a smarter thickness) was all sold out. Apparently the diy people have found the material here as well. I decided to buy 1cm and 2,5cm thick foam sheets. This was also a great opportunity for me to buy a heat gun that I’ve been wanting for some time, but had no relevant application for it.

The build – helmet

I started applying various methods showcased in the videos above, but quickly realized, that my son won’t be able to hold still for me to make the stencils/patterns of him. So thank you Evil Ted for providing me with ready patterns to begin with.

I made Evil Ted’s Large helmet following his instructions, with some slight modifications. I used the thicker, 2,5cm foam and it was really tough to fold into shape. Nevertheless, I managed to get the helmet in shape and using an authentic Lego Nexo Knight helmet for a model, I added some details.

initial photo of the eva helmet
The basic helmet, with some small details from the model helmet.

The visor played a critical role in the finished product. I used the thinner foam and drafted the rough shape, and finalized the design using an exacto-knife. I even used plasti-dip to coat the visor to get the required colours. The helmet itself was the original colour.

After the first fitting, I realized that the helmet is way too large. But it was accepted well. And as I had to make another, I decided to scale down the original patterns and make a smaller helmet. I used Adobe Illustrator to down-scale an uniform 80%, but after printing the patterns and cutting them from the foam, I realized that the parts won’t scale uniformly. Well it was fixed with a lot more extra cuts.

Two helmets almost ready
First helmet (blue, i.e. Clay’s) complete and second (green, i.e. Aaron’s) without the visor
Helmet with an open visor
The visor naturally can be opened

The thicker foam had this metal kind of pattern that I initially thought to rub off. It worked surprisingly well to imitate a metallic finish, so I left it on the ready pieces.

Finished helmets
Finished helmets. The ugly seams are caused by the stiffness of the too thick foam. My skills weren’t enough to make a nice seams.

The build – armor

With the awesome reception of the helmets, I decided to make a full armour set. Just using rough drawings, numerous fittings and adding layers after layers of foam, I managed to build something that actually resembles the original armour.

I bought some really wide velcro strips to be used to attach the chest piece to the back, two cans of the plasti-dip spray and even some fluorescent orange to resemble the orange lighted parts in the armour

Ches piece
Chest piece with the coat of arms / Nexo Power in place
Full armour and helmet set
Armour and helmet before the armour was completely painted

I also made quite an exact replica of the shields used in the toys, and printed some nexo powers to them. I ran out of the rubber spray, so the shield remained nice and red from the other side.

To complete the set, I quickly threw together two swords (the night before the Kindergartens halloween party, of course). The kids loved them, and they’re still actively in use. They haven’t been able to keep up the quite “active” play they’ve been used in.

This is my wives photo of the kids coming from the party

The verdict

Even though this was my first build, I was surprised how good the end products were. The 25mm foam is way too thick to be used and I truly understand why majority recommend the 5mm or the 10mm. I intend to continue to build these, I just need to source some material.

Materials used

  • 25mm EVA foam
  • 10mm EVA foam
  • Contact cement
  • Plasti-dip rubber spray
  • Fluorescent orange spray
  • Wide, self adhesive velcro tape
  • Heat gun
  • Scissors
  • Knives (exacto- and my really sharp kitchen pairing knife)

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