This was my Halloween costume for 2009. It took about a month and a half of planning and work. I built both a Pacman and Ghost, but this writeup will focus on the Pacman. The suit has a functioning mouth as well as speakers built in to play sounds from the game. It stands 5 feet tall on its own, and requires some crouching to get though doors while it's being worn.

Here is a video of the suit in action

Here is a list of the materials I used:

1/2" CPVC pipe

Cardboard boxes

Bleached muslin (Both 48” and 96”)

Expanding Foam

Yellow Fabric

Black sheer fabric

Yellow Latex paint

Black and Clear spray paints

Amazing Goop Plumbing glue

CPVC Primer and glue

Electrical Tape

Steel wire

External-frame backpack

Hip belt

Pulleys

Rope

Thera-Bands

Wheel Bearing Grease

Dry Teflon Bicycle Lube

Tools:

Measuring Tape

PVC Cutter

Paint supplies

Box Cutter

Respirator

Diagonal Cutters

Leatherman

Sharpie

Lighter

Scissors

Sewing Machine

Straight pins

Step 1: Planning

I spent quite a long time planning this project. I did initial sketches on paper and then did some very simple CAD work. Unfortunately in the Pacman costume I forgot to plan for the extra length that the PVC joints would create, so it caused some deformation of the frame shape.

Step 2: Building the Two Sides

There isn't too much to say here, it is simply a matter of cutting/labeling the sections of PVC pipe and beginning assembly. One note, make sure that you let the PVC cement dry completely before doing any kind of bend.

Also, while you are building the sides you should install T-joints for the crossbars.

Any area where there is not joint to assemble things I just used lots of electrical tape to hold things together.

Step 3: Putting the Outer Frame Together

This will depend somewhat on a persons size, but to give enough room I made my crossbars 24" in length. This gave me room to work inside the suit as well as leaving it narrow enough (just barely) to fit through doors.

In this step I also cut out one of the cardboard sides, but this was unnecessary since it didn't go on until near the end.

Step 4: Building the Mouth

The mouth was the bane of my existence for this project. I built two smaller pizza slice shaped frames that sat just inside of the main outer frame. I built a jig out of screws on my work bench to bend the CPVC in and then used a heat gun to make them hold the shape.

Once the two "jaws" were built, I installed them with steel wire and electrical tape at the back corner. This allowed them to be flexible, but to also hold in place.

For the movement I installed pulleys using steel wire and electrical tape, and fed the rope though them. This took the better part of a week to get working properly, so patience is a virtue. I didn't want to have to open the mouth back up, so I also attached Thera-Bands to act as a retraction mechanism. After some tweaking they worked beautifully.

The jaws did have a problem with recessing too far into the suit, so I added "stops" for them.

At this time I also installed the back pack frame using 1" PVC pipe and lots of electrical tape. In retrospect I wish I had waited until the mouth was completely finished since I didn't realize just how front-heavy the suit would be.

Step 5: Dressing the Mouth

I took the time to sew the black sheer and yellow fabrics together in a giant "I" shape. This I was then able to just lay over the jaws and glue on. It worked beautifully.

Later on in the process I decided to paint the inside of the suit black. I wish I had sprayed the PVC just prior to this point, and that I had sewn black fabric onto the inside of the yellow. There was lots of frustration trying to glue black fabric into that area once the whole thing was put together.

Step 6: Attaching the Muslin

Now that the mouth has been dressed it was time to attach the muslin. Patience and a good respirator are all that this required. I also recommend wearing gloves since the glue doesn't come off of skin easily.

Once the glue is dry just cut off the excess muslin.

Since my mouth pieces weren't built just right they stuck out of the primary frame at some point in their movement. Both were at different points. Because of this I had to cut a section of muslin out and re-attach it later once the cardboard sides were on. I left extra cardboard sticking out past the frame in the offending areas and just glued the patches of muslin to that.

Also, don't forget to leave a hole for yourself.

Step 7: Attaching the Sides

The sides of the suit are pretty simple. They're just big cardboard boxes cut to fit. I had trouble attaching cardboard to PVC, so the final solution was just to use expanding foam. It sticks to both materials and I was able to encase the PVC in the foam.

Also, once the sides are on I would recommend painting them with a primer. I had issues with paint soaking in and causing bubbling.

Step 8: Dressing the Outside

Now is the time for paint, etc...

I reattached the sections of muslin that I had cut out by gluing them onto the cardboard and got painting.

I had used spray-glue to attach posterboard to the surface of the cardboard so that it would look cleaner. It worked, but when I painted the posterboard swelled up badly and looked terrible. The fix for this was to stretch bleached muslin over the whole side and glue it on. This was very time consuming and required lots of straight pins. The end result looked very nice, so I would say to just go this route in the first place.

Once the sides are ready, simply paint the whole darn thing. Remember to lay something down underneath wherever you are working so that the paint doesn't get all scuffed up. I also painted Pacman-shaped eyes on with black paint.

Step 9: Finish the Inside

Like I said previously, I would take care of painting the inside black before you get to this point, but I didn't.

So here I took the time to foam in a pair of battery powered speakers (along with their battery module) and a battery operated fan. Using latex paint makes this thing very hot to wear even when it is in the high 30's outside.

Finish up any other interior work that needs to be done, like attaching the hip-belt if you haven't already.

Step 10: Finish the Mouth

I had problems keeping the mouth operating properly. It kept sticking on things; this required a lot of troubleshooting, but even after clearing things out I had to resort to greasing everything. Anywhere that the mouth rubbed outer frame I applied a liberal amount of wheel bearing grease. I also used a dry teflon bicycle lube on the pulleys and rope.

Step 11: Completed!

After a ton of work, the costume is completed. Have fun and expect to have a lot of people want to take their picture with you.

Here is the video of the suit operating again