Introduction: Lego Harry Potter & Green Ninjago Youth Costumes

I was in such a rush last year I was unable to finish this post last year. I did start writing it, so most of the information is timely. The one thing I will say is that these are completely impractical costumes. While I think they look amazing, they ended up just wearing the body to go trick-or-treating. I would definitely build these different if I were to do it again.

My boys are really into Lego, as like many other kids. One really loves Harry Potter as he started reading the series this past year. The younger one loves the Ninjago series. When I asked them what they wanted to be this year it was an easy choice. After a bit of hunting I found what I think is the best reproduction of a Lego minifig here on Instructables. User 1truedrum built an amazing Lego Lord Vampyre. After reviewing the pictures and getting a few questions answered I set off on my quest to create two Lego figures for this years Halloween.

Step 1: Measuring and Sizing

The first step is to figure out the ratio. Once a ratio is established it is very easy to get all your measurements. I started with an overall height measurement of the boys. They are about the same size so it makes it easy to do both. Then make sure you add a little room for their head to fit inside the costume. The ratio that I came to was: 32:1

Basically now I could take any measurement on the minifig and multiply it by 32. This was a very very handy ratio for imperial measurements because a 1/32" measurement on the minifig would be 1" on the costumes. This made all my numbers whole with no fractions.

After that make sure your overall ratio makes sense when broken down into the individual pieces. The hardest for me were the legs on the lego figure were much shorter than my boys legs. However this made it a little easier in the long run. I ended up making the costume legs a little longer and doing away with the hip like joint from the minifig.

Step 2: Materials and Sourcing

This was the first time I was going to work with pvc foam board, also called Sintra, or Celtec. I ended up finding a plastic supply place about 30 minutes away from me. If you don't have something like that you could probably ask a sign shop. For one costume you can just get a 4'x'8 sheet. You could probably get three costumes from two sheets, but I needed two sheets to do two costumes. Also depends on the size.

I also picked up the glue for it at the supply store, since they were they experts and knew what was needed. I think it was an all purpose cement.

Looking back, I would now probably make these costumes out of foam flooring tile. This would make them much more flexible and wearable.

Step 3: Lego Minifig Leg Base

I decided to start from the ground up. Since I had to cut 4 leg pieces I decided to make a template that I could then use my Dremel to cut out all the pieces. Taking a measurement of the router attachment on the Dremel I made a template out of extra plywood I had laying around. I cut the template using a hand saw for the straight edges, and a coping saw for the rounded part. Probably could have done it easier with a jigsaw or scroll saw.

I then clamped down the template to the plastic. The thing I didn't take into account is that going around the corners would create rounded corners when cut with the Dremel. So I ended up using a bit of blocking around the toes and heal of the template to fix this.

After that I cut all the facing pieces. To do the curve I used a heat gun to make it pliable. The hardest part to bend are the edges, so maybe cut these a little long then trim the ends (which I should have done in hindsight). The plastic will want to bend away from the heat, and I would just go with that. That way the hotter and more pliable side will stretch more. The better way to do it is to find something the same size that you can wrap the pliable piece around... maybe a paint can or something like that.

Once i had all the outside showing pieces cut and formed, I glued it with the solvent cement I got from the plastic supply place. I highly recommend a good respirator and a highly vented area. Even with me doing it in the garage with the doors open and a good breeze it was VERY strong. Once I got a good respirator I couldn't smell anything at all.

To glue it I cut blocks of wood to the right width then clamped the two sides of the legs to them. Then I would glue the forward facing pieces to the sides and put heavy'ish items to hold them in place. To save the costume from wear as the kids walk I made a horseshoe and glued it to the bottom of the leg (Thanks 1truedrum!).

As for mounting these to the boys I made a piece that looked like one of their soccer shin guards. I had a 2" piece of PVC that I could press the heated foam board against. This was just about perfect. I used the Dremel to cut some slits to sew in some elastic and velcro straps.

I glued these in place with some spacers to get the boys legs to the inside edge of the Lego legs. I then glued in some foam padding for comfort. and some foam to the bottom of the leg on the horseshoe.

Step 4: Lego Minifig Body Base

Body was much easier. Just get the measurement right and cut the front & back trapezoids. No template for this as it was all straight cuts. After cutting the sides, I cut holes for the arms and head. The arms I cut rather large ovals so they could put their arms down a bit and would not have to have them sticking straight out. Glued in a similar method as the legs.

I added some padding around the shoulders to try and keep it comfortable and not sliding around.

Step 5: Lego Minifig Head Base

The overall goal was to get the position/size/shape of the eyes done first. After that I could base all the measurements on that. So with the body done I could measure the distance from my boys shoulders to their eyes.

From there I calculate the different components needed.

  • The neck ring (plastic)
  • The lower curve (styrofoam)
  • The eye ring (plastic)
  • The upper curve (styrofoam)
  • The top ring (plastic

I cut out all the pieces, and used a dremel for the eyes while it was still flat. I then created a jig to shape the eye ring and join the two ends.

I notched both styrofoam curves to sit inside of the eye ring and the neck and top rings fit inside the styrofoam. I the plastic glue, but it would melt the styrofoam. I ended up fixing it with bondo that you will see later.

The last thing I did was to glue black screen over the eyes.

Step 6: Lego Minifig Hair and Mask

Keeping everything proportional, you end up with very big things. The Harry Potter hair was bad enough, but the Ninjago Mask was just insane. They were too heavy on their own, but added to the head... oh my! And I also had this idea they should act like real Lego and be able to come apart. I definitely succeeded in that! Thankfully all this weight was resting on their shoulders.

As you can see from the pictures I created rings out of styrofoam that would fit over the heads. The 2nd to top right was made to fit over the top ring of the head, and the top ring was solid.

I glued it all together with the foam glue from Lowes. Then carved and shaped them to the best of my ability.

Step 7: Lego Minifig Claws Base

I wanted their hand usable (as you will see why later), but also to show the lego claws. Using a paint can and some pieces of the plastic, I shaped them and cut holes for everything. This was a pain, but came out decent. I added some padding into the wrist area for comfort.

Step 8: Graphics and Printing

After I would work during the day on the physical side of costume creation at night I would work on the graphics. I scanned in the lego figures at a high resolution in photoshop. Then used illustrator to trace all the scans and recreate the screen printed designs on the minifigs.

My biggest concern was color matching. I wanted to make sure that I could paint the figures with one color then have the print come at least close to the paint so I could apply them without having to cut everything out.

I ended up getting Valspar paint from Lowes. The main reason was this site I found where I could look up any of their colors (spray can or mixed) and get the RGB/CMKY values. Now for this can't be exact, but

Here are the base colors I used:
Harry Potters Sweater: Valspar Almost Carcoal
Harry Potters Face (or any skin tone): Valspar Simply Peach
Green Ninja Shirt and Pants: Valspar Lucsious Green
Green Ninja Face (or any yellow Lego): Valspar Gold Abundance

With those base colors I then used colors that were similar to my scans. I then got these printed at a local sign shop that could do self-adhesive weather resistant vinyl. Some of the colors were close, others were off. I trimmed off some of the colors that were really different (like the skin color).

If you are interested the Illustrator files are attached to this page.

Step 9: Prep, Prime, Paint, Prints

The final work on the figures was to prep, paint, and apply prints. I sanded everything with orbital and palm sanders and by hand. I filled holes with bondo, and then sanded some more.

Once all that was done I primed every then painted the appropriate colors. Then applied the vinyl. Not a lot of directions, but a ton of work here.

Step 10: Arms, and Accessories

The arms were made with spandex that closely matched the color of the body. They were attached to the body via fabric tape, which worked ok, but not really. Should have found a better glue to get it to stick.

The Ninjago weapon was made of PVC pipe with fittings to look like the original. The blades shaped from styrofoam again. They just slide into the open holes so they can be taken out.

Harry Potters wand is again PVC with a plastic cup sanded and glued to the end. Then i put a flash light in the bottom so his wand could light up.

Step 11: Conclusion

Conclusion... I will never make anything like this again, and I suggest you don't as well. I think there are some good techniques in here to help you build stuff, so that is why I took the time to create these directions.

My boys had fun, but could have had more fun if they would have been able to actually wear their costumes :)

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Halloween Costume Contest