The electronics in the Thingamaplush are based on the Thingamakit design, available on Bleep Labs' website. I tweaked the design a bit to fit my own purposes, ending up with a sort of hybrid between the Thingamakit and the Thingamagoop. The electronics are stuffed into a plush robot I designed myself, and assembled with the help of my mother (how's that for some geeky mother-son bonding?)
This instructable will detail sewing the robot body, and stuffing it with my custom made board. Of course, you may remix any part of it to suit your own needs. You could design a different body, or install different electronics. Maybe an Atari Punk Console? Or a Robot Voice Modulator? It's up to you! You could even omit the electronics completely, to create a cute little robot toy.
EDIT: New videos added! See Step 11...
Please note that I made every effort to make my design safe for a toddler to use, but I can't guarantee its safety. If you're a parent you know how hard kids are on their toys - they are dropped, sat on, stepped on, chewed on, drooled on, and generally abused in ways that the Underwriters Laboratory can't even imagine. With this in mind, observe your child when they are playing with their Thingamaplush and make sure they remain safe. Unsupervised, I'd say the minimum age is 6.
Step 1: Parts and Tools
You'll need to hit two entirely different stores for this project!
- Fleece, felt or fabric of your choice. It doesn't really matter what you use. If your robot is being made for a child, use nice bright colours. They like that.
- Thread, suitable for the fabric you're using.
- Various buttons and other accents for your robot (optional)
- stuffing, preferably flame and heat resistant (just in case the electronics short out somehow)
- a short zipper or snaps (optional, for easy battery replacement)
- custom PCB (etched or perfboard - I recommend etched because it's more durable)
- blank perfboard
- components as listed in the parts list
- two 500kohm 10mm wide photocells
- three single pole double throw (SPDT) mini toggle switches
- four 22mm long hex threaded standoffs, and matching screws (probably 6-32 size)
- one mini 1.5"-2" speaker
- stranded wire
- lead-free solder (just in case)
- a 9V battery and 9V battery clip
- heat shrink tubing
- wire wrap tubing or aquarium tubing
- a sewing machine (optional - you can do it all by hand if you like)
- a sewing needle
- PCB etching equipment
- soldering iron
- assorted circuit assembly tools
- glue suitable for fabric, for attaching accessories
Step 2: Build the Electronics
I highly recommend etching a PCB for this project. They are more resilient and reliable than perfboard (IMO) and therefore more suitable for use in a childrens toy.
Start by etching your board using your preferred method. I won't go into detail here - check out my other instructable on how to use the toner transfer method to make a PCB.
Now, populate the board using the parts list and board layout as a guide. Start with the ICs, and then the resistors and caps. Make sure the two electrolytic capacitors are installed with the correct polarity. When soldering the LEDs, bend the leads a bit so that the LED is flush with the edge of the board. LEDs are polarized too, install the the right way! Finally, solder in the potentiometers and the 9V battery clip.
Two of the switches will have three wires, one of them only needs two. Solder about 2-3" of wire onto the pins of the switches, and finish them with heat shrink. Note that the body of the switch must not be longer than the standoffs, or they won't fit!
Cut a piece of perfboard equal to the size of the PCB (3x3 inches). Drill holes in the four corners that match the holes of the PCB. Drill three more holes that match the shaft diameter of the switches. You can put these three holes wherever you like; I chose to put them in a line. Mount the switches on the perfboard, using one of the supplied nuts. Save the second nut for later.
Now it's time to solder the switches onto the PCB. Match up each switch to a position on the PCB, and solder its wires in place. Make sure that the middle pin on each of the switches with three wires goes to the middle pin on the PCB. Soldering can be tricky, since you have to solder to a pad on both sides of the board.
With the switches installed, you may link the perfboard to the PCB using the standoffs. The perfboard should be mounted as shown in the picture. I used flathead screws on the perfboard side, so that the screw heads wouldn't cause the fabric to bulge. Don't tighten the screws completely just yet though, as you'll need to remove the PCB from the perfboard for mounting inside the robot's head later on.
Solder long wires to the leads of the photocells, and finish the joints with heat shrink. You may also want to add a glob of hot glue to where the leads connect to the package of the photocell for added strength.
Finally, solder long wires to the speaker terminals and finish the joints with heat shrink.
Don't solder the photocell or speaker wires to the PCB yet - you need to mount them inside the Thingamaplush's body first.
Step 3: Mark Out the Fabric
You may use my pattern to make your Thingamaplush's body, or design one of your own! However, note that the electronics are designed to fit inside a 3x3x3 inch head, so if you do design a different body then you may have to modify the electronics accordingly (ie. adding wires instead of soldering the pots and LEDs directly to the board)
I decided a cube-shaped robot would look great for this, and I gave it a cute anime-style face to match. For the fabric I used fluorescent green artificial suede, because it's tough and doesn't stretch. Black suede is used for the face, arms and legs. Small bits of semi-opaque nylon fabric are used for the eyes, mouth and photocell hands so that light can get through.
In total, I used about 12x36" of green suede, 12x12" of black suede, and less than 6x4" of white nylon.
Of course, you may use whatever you like, but I do suggest using a fabric that does not stretch for the body!
Cut from green suede:
The head is larger than the body (it looks cuter that way - remember, this is for a two-year-old girl!) The PCB I designed is 3x3, so to accommodate the board with a bit of breathing room, mark out six 3.75x3.75" squares on the fabric. This will give a 0.25" seam around all the edges, and 1/8" of room for the board on all sides.
Mark out the area of the face that will be cut out on one square (2x2"). On three squares, find the exact center so that holes for the neck and potentiometers can be cut. On one square mark out the centers of the switches (this is the top of the head). Leave one square blank (this is the back of the head). Cut out the squares and set them aside.
Next draw out the squares for the body. The body is 2x2x2", so draw six squares that are 2.5x2.5". This will give a 0.25" seam on all sides. On two squares mark the positions of the arms (centered and 0.75" from the top). On one square mark the positions of the legs. On one square find the exact center, for mounting the neck. Leave the last two squares blank. Cut these out and set them aside, too.
Finally, mark out the patterns for the hands and feet and cut them out as well. I used lids from various bottles as stencils.
Cut from black suede:
Mark out the patterns for the arms, hands, legs and soles of the feet. Cut them out.
Mark out a 3x3" square for the face, and draw the face on the back. You don't have to use the same design as I did, but remember the LEDs are positioned on the board such that they shine through the eyes. If you design a different face you may need to position the LEDs differently. Cut out the face and set it aside.
Cut from white nylon:
This fabric is semi-opaque, so that light from the LEDs can shine through, and so that light can reach the photocells. For the face, cut a 2x2" square of nylon. For the hands, cut two 1/2" squares.
Handy Cut List:
6 pieces 3.75" x 3.75" (head)
6 pieces 2.5" x 2.5" (body)
2 pieces 3/4 semicircles, 0.66" inside diameter, 1.66" outside diameter (foot tops)
2 pieces 1.75" x 1" (hand "tops")
2 pairs (4 pieces total) hand "sides," 1.5" long by 1" high (as per picture)
1 piece 3" x 3" (with face cut)
2 pieces 5" x 1.87" (arms)
2 pieces 4" x 1.87" (legs)
2 pieces 1.75" diameter circles (foot soles)
1 piece 2" x 2" (facial features)
2 pieces 0.5" x 0.5" (hand sensor covers)
Step 4: Sew the Head
Start by sewing the white nylon onto the black face. Use small, tight stitches all the way around the facial features. I used the applique stitch feature on the sewing machine. Well, my mom did - I watched.
Next, sew the black face onto the green front of the head. Again, sew close to the edge to minimize flaps. Little toddler fingers love tearing at flaps of fabric! A machine applique was used for this, too.
Now you may sew the square panels together. By hand or using a sewing machine, sew as accurately as you can along the line. Remember, this Thingamaplush is a robot and the goal is for it to be a cube! On the back panel, only sew along the top and halfway down each side - you'll need access for mounting the electronics.
When the head is sewn, turn it right-side out.
Step 5: Sew the Arms and Legs
I'm rather proud of my design for the arms, specifically the use of wire wrap to give structure to the arms and protection to the wires inside. You could use any tubing though, like clear aquarium tubing, as long as it's flexible.
The legs and arms are easy. Cut out a 3.5x1.9" rectangle of fabric for each of the legs, and a 5x1.9" rectangle for each of the arms. Fold each piece lengthwise and sew along the edge and the end. Then, using a knitting needle or a pencil, flip the leg or arm right-side out. The end was sewn over to make this process easier. Once the legs and arms are right-side-out, cut off the sewn end.
Hands and Feet!
Start by sewing the white nylon patch onto the "palm" of the hand. Use the same applique stitch as on the face. You may need to do this by hand.
Do the hand itself next. You'll probably have to do this by hand as well since it's so small. Make sure you follow the curve. Use tight stitches so the hand holds together.
Finish the hand by sewing on the palm. Again, small tight stitches are better. You may be able to use a sewing machine for this, since the seams are straight.
Next up are the feet. Fold the top of the foot in half and sew along the end to form a cone. Take one of the legs, and use a whipstitch to sew the top of the foot onto the end of the leg. As usual, nice tight stitches are best. Now take the "sole" of the foot, and loosely baste it onto the top of the foot. Pins are too large for this so it's easier to use a temporary stitch. On a machine or by hand, sew 3/4 of the way around the edge of the foot using a decorative stitch. A small hole is left for stuffing the foot later on.
Step 6: Sew the Body
The body is sewn together in much the same way as the head. If you like, you may mark using letters how the panels match up. I did this more for my mom's sake than for me, to make it easier for her to sew on the machine. Make absolutely sure that you get the orientation of the sides and bottom right! On the back panel, sew the top and two sides, but leave the bottom open for stuffing.
You may cut holes for the neck, arms and legs before or after the body is sewn together. Just make sure the holes are big enough for the arms and legs.
Now you can attach the arms and legs. This is done by hand using either a whipstitch or a plain stitch. Really, anything that holds the appendage in place and looks reasonably neat will do. Pass the appendage through the still inverted body and through the appropriate hole. You may want to cut "tabs" into the end of the arm that is being sewn to the body, to make things easier. Carefully stitch all the way around, leaving no gaps. It might help to leave a piece of the wire wrap or tubing in the arm, so that you don't accidentally sew the opening closed.
Sew each appendage onto the body. Things will get crowded fast, so try stuffing the arm or leg inside once it's sewn on. Also, it's easier to do the arms first.
With the arms and legs attached, you can turn the body right side out. It's up to you if you want to give the robot a neck. I decided it would be too difficult to sew, but you're welcome to try. I simply sewed the head directly onto the body, using a whipstitch around the hole where the body and head meet. You could also use a plain stitch here, if you can maneuver the needle in there.
Step 7: Add the Hand Sensors
The first electronics to go in are the photocell sensors in the hands.
Start by running a length of wire wrap from one "wrist" to the other, straight through the robot's body. If you're using tubing you will need to cut an access hole in the middle to feed the wires through to the head. The wire wrap can be opened at any point, so no hole is needed. Then, run an equal length of 14 gauge solid wire through the wire wrap. This makes the arms poseable. Finish the ends of the wire by folding them back on themselves, to prevent the wire from poking through the fabric.
Each hand gets its own sensor (or just use one if you wish). Glue the sensor onto the white pad on the palm of the hand, and wait for the glue to dry. Stuff the hand with stuffing.
Run the wires from one hand through the wire wrap tubing to the body of the robot, so that the wire exits through the wire wrap inside the body. Pull the wires from the body end until the hand is flush with the "wrist." Then carefully sew the hand onto the arm. Do the same with the other hand.
Choose any one wire from each hand, and solder the ends together. Finish with heat shrink. This will form a series circuit between the photocells. The other two wires will be soldered to the PCB in the robot's head.
Step 8: Finish the Feet and Add the Speaker
The legs need wire wrap tubing too! Run a 12 or 14 gauge solid wire inside a length of wire wrap, equal to the length of both legs and the gap between them. Fold over the ends of the wire as you did with the hands. Bend the wire wrap into a U-shape and slide the wire wrap into the legs from inside the body. When this is done, stuff the feet with stuffing, and sew them closed.
The speaker can go pretty much anywhere inside the body. The best place to put it is up against the chest, and it stays in place pretty well on its own when held in place with stuffing. With the speaker in place, run its wires up through the neck and out the access hole in the head.
At this point you may solder the wires from the photocells and speaker to the last remaining positions on the circuit board. Attach a battery and turn it on to make sure everything works. It's (obviously) important to do this testing before everything is sewn up! I freaked out the first time I turned mine on and it didn't work, but I had forgotten to solder some components on the top side of the board. Oops.
Step 9: Mount the Circuit Boards
Detach the perfboard from the circuit board, if they are still connected together. You may want to put a layer of foam between the perfboard and the fabric, but this is optional. I didn't. Feed the switches through the holes and tighten down the second set of nuts to hold the perfboard in place.
Realign the circuit board with the perfboard, first feeding the potentiometer shafts through the holes on either side of the robot's head. Then tighten the screws that attach the circuit board to the perfboard, and tighten the nuts on the potentiometers. The two screws closest to the robot's face are tricky to access, I fed a screwdriver through the robot's body and through the next to get to them. Don't worry, he was heavily sedated and didn't feel a thing.
I also cut a small piece of craft foam to place between the circuitry and the stuffing. This is optional and probably won't matter if you don't include it.
Plug in the battery and make sure that everything still works.
Step 10: Sew Up the Head and Body
If everything is squawking and beeping as it should, you may now stuff the body with stuffing. When you do this, make sure the battery clip remains accessible - the battery will be inserted after the stuffing. Make it's good and tight; the body should be relatively stiff (though still squishy). Reattach the battery, stuff it in, and sew up the access hole with an appropriate slip stitch. It works best if you fold over both seams and pin them in place as you sew.
Do the head last. Pack more stuffing into the lower half of the head only - there's no need to put any stuffing between the perf board and the PCB. Make sure you fill all the tight corners. When this is done, pin the flaps in place and sew the head shut with a slip stitch.
The final step is to attach the knobs. Loosen the retaining screws and slide them on. Then re-tighten the screws. If you use the same potentiometers as I did, beware of the shaft length. The shaft on the switched pot was longer, so I had to cut about a centimeter off the end to make it equal to the other pot.
And that's it! Add embellishments using fabric paint if you like, or just leave it plain. Your Thingamaplush is now ready to be enjoyed. :)
Step 11: Videos
First Prize in the
SINGER Kids Crafts Contest