This life-size Super Mario question mark block plays random Mario sounds when you hit it at the bottom. The step-by-step Instructable explains how you can make one yourself. Design and development by Piem Wirtz and Simon de Bakker.

Plush Mario Sound Block from Piem Wirtz on Vimeo.

Tools
sewing machine
iron
crochet needle
pins
needle & thread
hot glue gun
scissors
cutting mat
sharp kitchen knife
ruler
wire stripper
small screwdriver

Materials
70 cm yellow fleece (140 cm wide), cut into 6 squares (32x32 cm)
question mark template
white and black fleece or felt
fusible interfacing
yellow and white thread
yellow zipper (Optilong, 60 cm)
yellow rope
snap hook
packing rope
custom sound module (order at Simbits)
2 AA batteries
adhesive backed velcro
2 firm plastic sheets (30.5x30.5 cm)
4 light rubber bars (30x5x5 cm)
1 sheet of soft foam rubber (0.5 cm thick)
double-sided tape
aluminum foil
1 flexible plastic sheet

Step 1: The Cover

The yellow cover with the question marks is the eye-catcher of your Mario block. You pull it over the frame later on, so it gets it's final shape.

Question Marks
1. Iron the fusible interfacing to the backside of the white fleece. Make sure you leave the protection in place on the other side of the interfacing.
2. Use the question mark template to transfer the drawing onto the white fleece. Cut the shape out of the fabric. Repeat for the second mark.
3. Cut strips of black fleece to create the drop-shadows on the side of the question marks.
4. Position the question marks and black strips on a yellow square and iron them on. Put a piece of cotton or baking paper between the iron and the fleece so the interfacing will not stick to your iron.
5. For added durability, sew around the question mark (optional).

Cube
6. Pin four yellow squares together (right sides facing each other) to create the walls of the block. Make sure you alternate between a plain square and a square with a question mark. Stitch them together on the sides. You have approximately 1 cm margin for the seams.
7. Take another square and pin it to the top. All right sides facing inwards. Stitch completely around all edges.
8. Take the last square and pin it to the bottom. Leave two sides open! Stitch two sides.
9. Align one side of the zipper along the bottom of the cube. Check that you do not position it inside-out! (You can fasten it with one pin, turn outside-in and see how the zipper will end up.) If all is correct, pin it and sew loosely by hand. Remove the pins.
10. Open the zipper and align the other side to the walls of the cube. Pin and sew by hand.
11. Sew the zipper with the sewing machine. Tip: start sewing with the zipper half-opened. When you reach the pulling tag of the zipper, you cannot pass it with the machine because the tag is too wide. Release the presser foot of the machine. Gently pull the cover towards you so you can reach the zipper tag. Close the zipper, re-position the presser foot and continue sewing.
12. Remove the hand-sewn thread, open the zipper and turn the cover outside-in.

Your cover is now finished.

Step 2: The Switch

The switch is positioned at the bottom of the block. Actually, the whole bottom IS the switch. It consists of two conductive layers that are connected to the sound module, with a spacer in between. If the layers touch each other, the circuit closes and the sound is triggered.

1. Cut two sheets of firm plastic, 30.5 cm square.
2. Define the midpoint of each square. Drill a hole in the middle of one sheet. This will be the top of the cube, where the suspension rope will run through. Put it aside.
3. Draw a square from the midpoint on the other sheet, approximately 15 cm wide. Drill holes at the four edges. This will be the connection point for the suspension rope. Drill two more holes, an inch outside the square. Here the wires from the sound module will run through.
4. Turn the sheet upside down. Stick double-sided tape in between the four holes and create a triangle reaching towards one of the outer holes.
5. Cut a piece of aluminum foil in the same shape as the taped figure. Gently stick it to the sheet. This is one part of the switch.
6. Cut a round hole (15 cm diameter) in the sheet of soft foam rubber. This will be your distance-keeper.
7. Cut a square of 20 cm from a flexible (but not too floppy!) piece of plastic sheet. Cover it with aluminum foil.

Tip: the slip-in folders in which you store documents are perfect. It should be able to bend and touch the aluminum when you hit it, yet at the same time spring back to it's original position so it will not make contact all the time.

Now you are done preparing the switch.

Step 3: The Frame

The frame gives shape to the block. It is not a solid box, but an open structure so the sound is not obstructed by any walls. The frame has some flexibility to allow for the cover to be pulled over it, afterwards.

1. Take the sheet of plastic with the hole in the middle, the top of the cube.
2. Heat up the glue gun.
3. Cut four legs out of dense cell-foam rubber.
4. glue the legs to the top sheet, neatly positioned in the corners.
5. Cut eight flat, rectangular pieces of rubber. These will be used to keep the legs in the right position at the bottom sheet.
6. Take the sheet of plastic with the aluminum foil on the bottom. Make sure the aluminum is facing the table! Position the four legs in the corners of the sheet.
7. Glue around one leg, stick two flat pieces of rubber around it. Hold the leg in the correct position when glueing. Remove the leg when the glue has dried. Repeat for all legs.

Tip: mark one side of the bottom & top sheet, so you remember the relative position of the legs.

8. Run the yellow rope through the hole in the top. Connect the snap hook at the inside end of the rope.
9. Stick a piece of self-adhesive velcro in the top-side middle of the bottom sheet. Stick the other side on the bottom of the sound module.

The frame is ready for assembly.

Step 4: The Sound Module

The sound module is a custom made circuit board, packed in a small box together with batteries and a loudspeaker. You can order the full module at simbits.nl. DIY hackers can also consider to buy a cheap keychain with Mario sounds and use that as a source (that is how we started the project, anyway).

Once you have the sound module, you need to insert the batteries and strip the wires to prepare it for assembly.

Step 5: Assembly

You have now created all the elements to compile the Mario block. Follow the step-by-step instructions carefully, since the order in which you act does matter.

1. Take the bottom sheet with the velcro. Stick the sound module on top.
2. Run four strings of packing rope through the four holes at the square. Make thick knots on the bottom (= the aluminum covered side).
3. Lift the sheet by gently pulling the four ropes at the same time. You need to find a perfect balance, and then tie them all together. The height of the knot should be somewhere halfway the height of the cube. Be patient! It is crucial to find the right balance, since this will determine how straight your Mario block will be suspended in mid-air later on.
4. Run the wires of the sound module through their respective holes. It doesn't matter which one goes where.
5. Flip the sheet upside-down. Connect the wire that is running through the top of the aluminum shape to the foil. You can connect it by soldering it, or by clamping it firmly to the surface with a snap. The low-tech way would be to simply tape it to the aluminum foil.

Tip: fold a piece of aluminum a few times and put it on top of the wire. Run sticky tape over the total, including an inch of unstripped wire. As long as it is firm and makes good contact, you're ok.

6. Connect the other wire in the same way to the other aluminum covered sheet.
7. Slip the foam with the round hole in between the two aluminum sheets.
8. Pin the flexible sheet to the foam, stitch loosely at four corners. Then remove the pins.
9. Put double-sided tape on the foam and stick it to the bottom sheet.
10. Test the switch: hit it gently in the middle, so the aluminum layers make contact.

You should hear a random Mario sound and the switch should get back to it's starting position. Now put the entire assembly on the floor. It should not make the switch close, you should hear no sound. If it does, check the flexible sheet. You may want to replace it with a less flexible one.

Step 6: Finalizing

Now you are ready to pull the cover over the frame. It is a tight fit, but the frame is flexible enough to be squeezed in.

1. Take the fleece cover and the top part of the frame (= with the legs). Gently bend the frame and slide it inside the cover.
2. Take the switch and check the marks for the leg positions. Slide the switch into the cover. Before you put everything in place, reach for the inside and connect the snap hook to the packing rope pyramid.
3. Position the legs into their slots.
4. Close the zipper and pull the cover straight.
5. Feel at the top of the cube to find the yellow rope, which is still trapped in the inside. Make a tiny cut and flip the rope out. You can use the crochet hook.
6. Suspend your plush Super Mario sound block from the ceiling.

Playtime!