Transforming PRIME on a Dime




Introduction: Transforming PRIME on a Dime

Inspiration for this Costume:
The pleading eyes of my child who had just asked to be a real “transforming transformer” for Halloween. After I stopped laughing, I started crying...sigh.

Motivation for creating this Instructable:
You. Because if you’re reading this right now it means you’ve recently heard this outrageous plea yourself. You’ve found what I didn’t find: step-by-step instructions for a transforming auto-bot. Here’s to your adventure! May you experience the magical gleam in your child’s eyes this Halloween and feel like an invincible super hero when you hear others telling your child that he has “The Coolest Mom Ever!”

So what does it take?

1 giant mess (Let’s be honest, could it be so incredible without one??)

3 boxes of similar widths and varying heights

1 average size roll of each:

blue duct tape

red duct tape

gray duct tape

1 can chrome colored spray paint
1 can of black spray paint (ask around the neighborhood for these)
4 wide mouth mason jar canning lids (no rings)

1 black sheet of card stock

8 dessert size paper plates

1 sheet of nonstick parchment paper

1 yard of ribbon

1 yard of elastic

2 under cabinet LED lights

2 red LED bicycle lights or bicycles reflectors

Other various and random cardboard components lying around your house

I exploited the garbage and used what was on hand already, so the total cost for my Optimus Prime was about $20.

Step 1: Step One: Foundation

Measure the chest width of the future auto-robot.

Add an inch or so to this measurement for ease purposes.

Take this number and search for three boxes with the same width* and differing heights*.

*Keep in mind that it can’t be so wide that person is unable to lower their arms. It needs to be comfortable sitting on the chest and under the arms.

*As long as the widths of the boxes are similar, it is possible to adjust the height and or length of a box by piercing through one side of the cardboard while leaving the other side in tact and folding it down as detailed.

*When choosing cardboard, be aware that any existing holes may create weakness later on; especially, along the vertical weight bearing sides.   

Step 2: Step 2: the Hood (Box #1)

Measure in on each side of the front-end of the hood a distance that looks proportionally correct to your size of truck. (For my 12” truck width, I came in 2” inches on each side.)
Measure in this distance on each side down the front. Cut* the top, front, and bottom. Push these inside the box and secure temporarily with masking tape. You should still have cardboard seams on the entire back.

Cover the sides and top completely with red duct tape.

Carve a semi-circle out of the back and bottom panels of the box. (This won’t be seen when worn; it allows this piece to lay down on the chest and belly, while in robot form.)One of the objects of this design was to keep the front windshield and hood in front of the person at all times so there would be no question about “who it is” in either robot or auto form.

On the back, measure one to two inches down from the top and pierce two holes on the right and left sides. This box hangs from the neck by a ribbon and this is where the ribbon is threaded and secured through the box. 

*When cutting cardboard, always use a sharp knife and saw slowly back and forth. Keeping your hand clear, hold the box firmly while cutting, and always make sure the blade is not facing your body. Also, duct tape can cover a plethora of sins, but try to mark and cut as precisely as possible…you’ll be glad later.

Step 3: Step 3: the Cab (Box #2)

Mark a line on the front of the second box indicating where the hood will hit the cab.

Measure back from the top front edge 1-2 inches and mark this line. On the sides, connect these to lines. This will create the angle for the windshield.

Cut the side and top lines. Press this front panelinto the box to create the angle and secure temporarily with masking tape.

Now cut the original front lower line and remove the panel from that line downward. Also remove the back and bottom panels.

Measure and cut down the center front of this piece to create two pieces of the cab.

Step 4: Step 4: the Windshield, Visor and Flames

Cover the windshield surface with either black card stock or if you have it on hand, use black duct tape.

Using blue duct tape, tape* up the entire side and top surfaces of both pieces of the cab.

Find a long, narrow piece of cardboard slightly longer than the width of your truck. This will be the visor. (The side of a box of cereal might work well depending on the size of your truck.) Keep in mind that part of the visor is folded down along it's backside and taped onto the windshield using that allowance. The visor needs to be wide enough to allow for this. Spray it chrome, or cover the surface with gray duct tape.

Fold lengthwise one inch along the back edge. This creates an allowance for attaching the visor to the windshield. Notch the allowance about one inch from the ends as depicted in the photo. Crease here. This will allow the corners to lay correctly once the visor is permanently attached to the windshield.

Cut the visor at center and attach, taping the allowance firmly onto the windshield.

Now for the fun part! Create a border around each windshield using gray duct tape. Make the side windows using black card stock or black and gray duct tape.

Create red and blue flames. Duct tape is hard enough to cut alone. I discovered that if you place a strip of duct tap on a nonstick parchment paper, the tape is A LOT easier to cut, especially on a curve; it then peels right off the parchment and is ready for application. (This is a great time to involve little hands, either for tracing the flames, cutting if able, or actually applying the flames onto the truck.) Have fun with this.

Using a piece of blue duct tape, connect the two pieces along the top center rear panels. This allows the chest piece to spread open when in robot mode.

Line up the hood and the cab and tape these together on the inside corners. (This is shown using black tape in the last photo.)

*To avoid creases and bubbles in when taping, pull the tape firmly and place the tape slowly and carefully. When possible, it helps to cut the tape from the roll before applying.

Step 5: Step 5: the Sleeper (Box #3)

Mark the “sleeper box”FRONT, BACK, SIDE, and BOTTOM panels. Lay the “sleeper box” down on it’s back and remove the bottom panel (if you haven’t already done so to adjust the height .)Determine what height you want the actual sleeper to begin (notice it looks like it stands on metal supports. (My supports were six inches.)Measure up this number from the bottom on all four corners and cut from these points to the bottom—4 separate cuts.

Now fold in the front and back panels like you were making a new box. Slice toward the back on each front side in order to be able to fold down the side panels as shown. Trim these panels down. Now the sleeper is ready to be taped completely around the sides, front/back and top panels. Tape the supports in gray.

This piece is worn like a back pack. Pierce four holes and thread through a piece of elastic band or string and secure on the inside with knots*.

*Placing a washer on the inside of each of the four holes will prevent the elastic knot from bursting through the cardboard.

Fold in the ends of a cardboard wrapping paper tube to create two points on each end. Cut the tube in half or to the size you need and spray paint these chrome. Attach the tubes on the front of each side by putting duct tape up the tube and across the box.

Where the tube meets the top of the box, slice a horizontal hole in the tube, push a small piece of blue duct tape through and secure to the top of the sleeper.

Step 6: Step 6: Trailer Wheels and Hubs

The trailer wheels and hubs rest on the outside of each leg, but are secured using elastic.

Find a box with mitered edges, or create the miters yourself from boxes lying around your house. The miter is important as it allows the hubs to bend with the knee while in robot form. There are two hubs on each leg, so you will need four identical pieces--no more than 3 inches in width. The length depends on the thigh and shin length of the wearer.The height of these pieces shouldnot be much bigger than the width of the person’s legs.

Cut a semi circle into each hub so that the wheels can be seen later.

Cover these in red and blue duct tape.

Spray paint 2 dessert size paper plates with black spray paint, or paint/color them black with a marker. Cut each plate in half and and secure the “wheels” on the inside of the hubs with duct tape and hot glue.

Hinge two hubs together on the top of the hubs (into the miter). Flip the hubs over and hinge from the inside also--as depicted in the photos.Repeat for the opposite side hubs.

Along the top back of each hub pierce four holes. These will be used to thread elastic through when it gets time to ‘roll out.’

Step 7: Step 7: Front Hubs and Wheels

Measure the side panels of the hood (red box) and cut out two identical panels to this out of cardboard. Cover these with red duct tape

Take the Sonotube (mine was 8” Sonotube) and cut a front hub.One side should be straight, and the other should match up to the angle of the hood side panel. Cut the opposite side hub also.* Cover these in red tape, inside and out and secure onto the top of new side panels.

*Remember that the angle is opposite on the other side.

Spray paint two dessert plates completely black. (Front and back).

Make the wheels by gluing two plates bottom to bottom. Repeat for the other wheel.

Cut the two corners out of a box. These will serve as the axle rod and align the wheels with the hubs and truck instead of the inward angles of the hood. Tape the the box corners toward the front of the wheel then secure with tape and/or hot glue onto the side panel.

Spray paint two more upside down dessert plates chrome. Trim the lip of the plates and cut out the hub caps from these as shown in the photo. Hot glue the center of the hubcaps down onto the center of each black plate.

These new wheel/side panels are carried in the hands and so make handles on the inside of each using duct tape.

Step 8: Step 8: Grill, Bumper and Headlights

Find a shoe box lid that is similar in width to to front of the hood. (You could also convert a cracker box or other cardboard box by removing the front and part of the side panels until you have the desired depth of your grill.)

To create the bumper, cut and fold down a cereal box to the desired height and width.

Spray the grill panel and bumper chrome.

Tape the back of the grill and bumper together. Also tape the bottom of the bumper to the bottom of the hood.

Now poke 2 holes through both the “grill plate” and the hood. Thread tape through these to ensure that this piece will not be going anywhere.

Next accordion a long piece of cardboard until you have your desired grill look. Spray this chrome as well and hot glue into place.

By now you have probably used up the blue and red duct tape. Take these empty duct tape rolls and spray paint them chrome.

Glue together two metal wide mouth canning jar lids with the silver sides out. Now hot glue the duct tape roll to the top of the metal lids.Place your under cabinet lights* inside the roll to create a headlight. Repeat for the other one.

*The “under cabinet” lights that I found at Dollar General were adhesive, but if yours are not, be sure and engineer it to stay put. You may have to tape it down onto the lid securely before gluing on the duct tape roll.

I’ll be honest. At this point it was “go time”, so I just hot glued (like mad) the headlight to the grill and bumper and also secured it with duct tape around the top just in case. This worked fine and there was no issue. If I had more time I would have used a nut and bolt from the side of the grill through the duct tape roll.

Step 9: Roll Out!

Ask around the neighborhood for a fabric Optimus costume, or look at the thrift store. If you don't find one, wear a red sweater and gray pants. 

Put on the back pack. Place the hood and cab on your chest with the ribbon around the neck.

Thread and tie the elastic through the trailer hubs and around legs.(Be extremely careful here not to wrap too tight.)

Transform down by grabbing the cab with the thumbs and pushing forward and out as you kneel and duck into the cab/hood. When you extend the legs and put your belly to the ground the sleeper will stand up with exhaust pipes in the air. Place the hands with the front hubs up against the sides of the hood...ROLL OUT!

...and there you have it...that gleam in the eye!!

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13 Discussions


2 years ago

It's still 2 months until Halloween but I'm incredibly intimidated to try this


5 years ago on Step 9

i am sooooooooooooooooooooooooo happy i found this you have no idea how long ive been looking!! thank you thank you thank you!!!!


6 years ago on Introduction

My son wanted to be Optimus Prime this year. And he added a bonus: an actual TRANSFORMING Optimus Prime. So glad I found this! You rock! Thanks for sharing. ^_^


7 years ago

\_('_')_/ cool


7 years ago on Introduction

This is seriously super-cool. My son is only 9.5 months old, so he hasn't asked for one of these yet, but when he does...I'll be ready!

You ARE the coolest Mum EVER!!! ....apart from mine, of course...then again, she never made me an Optimus Prime costume!


7 years ago on Introduction

That is awesome. I love the transformation!


Reply 7 years ago on Introduction

Thanks! I love Halloween for one reason: "creation!"


7 years ago on Step 9

Totally awesome! Great job! Gotta love that gleam, thats what its all about :)