We’re back with another edition of drawdio fun!
This hexapod features an 8 ohm speaker hat and 10 conductive patches (one on the side of his head and 9 on his tentacles) that allow you to access the squeaky theremin-like powers of the Drawdio pcb hidden inside.
Bill Of Materials*:
- IC1: TLC551
- Q1: PN2907
- C1: 680pF ceramic capacitor
- C2: 100uF / 6.3V capacitor (or higher)
- C3: 0.1uF ceramic capacitor
- R1: 1/4W 5% 10 MEGAohm resistor (Brown, Black, Blue, Gold) OR 1/4W 5% 20 MEGAohm resistor (Red, Black, Blue, Gold)
- R2: 1/4W 5% 10 ohm resistor (Brown, Black, Black, Gold)
- RA: 1/4W 5% 10K resistor (Brown, Black, Orange, Gold)
- RB: 1/4W 5% 300K resistor (Orange, Black, Yellow, Gold)
- Drawdio PCB
- 8Ohm speaker
- CR2032 holder
- Plush pattern (I modified this one from FutureGirl) Make certain that which ever pattern you choose allows for concealing the PCB, which is 3.2in x 0.5in x0.03in.
- 22 gauge solid core wire in red
- 22 gauge solid core wire in black
- Felt, 1 sheet for main color and about 1 inch x 0.5 inch of contrasting color (any non-stretchy fabric will work)
- Embroidery floss
- 4-ply conductive thread
- Needle threader
- Fray check or nail polish
- Optional: Pins to hold your pattern to the felt while you cut it out. You could trace the pattern on the fabric instead.
- Optional: Fabric paint or embellishments to add details to your creation
- Soldering iron
- Size 24 tapestry needle- A narrower size would work as well, but any wider and it won’t fit through the holes on the battery holder.
- Needle nose pliers
- Optional: if you’re using the octopus design, a chopstick/ pencil/ popsicle stick will help you poke the stuffing into the ends of the tentacles.
- Optional: Hot glue/ glue gun
- Needle nose pliers
1. Solder the 551 chip in place, while using a bit of thermal tape to hold it in place on the PCB if necessary. Be certain to note the little notch to make sure that you’re inserting it properly.
2. Solder in the the PNP to the Q1 spot, leaving enough room to bend it flat against the pcb.
3. Solder the 680pF ceramic capacitor in C1.
4. Solder the 100uF / 6.3V capacitor (or higher) in the C2 spot being careful not to put it in backwards.
5. Solder the 0.1uF ceramic capacitor in C3.
6. Use your snips to trim the leads, cutting them close to the solder joint. [For tips on trimming best practices, check out this forum.]
7. Solder the resistors in place. Since they aren’t diodes, there’s no need to worry about accidentally putting them in backwards. R1: Brown, Black, Blue, Gold OR Red, Black, Blue, Gold.
8. R2: Brown, Black, Black, Gold
9. RA: Brown, Black, Orange, Gold
10. RB: Orange, Black, Yellow, Gold
11. Trim off excess leads.
12. Line the PCB up with the section of your pattern where you want to put it, and measure for the 4 lengths of wire (2 red and 2 black) that you’ll need to connect to the pcb to the speaker and also from the battery to the pcb. You’ll be winding the end, so be sure to add about an inch.
13. Strip about 0.5 inches from both ends of each piece of wire from Step 12.
14. Solder the wires in to the holes for the speaker and battery holder.
15. So that you can sew the wire securely to the felt, spiral the ends as shown in the pictures above.
16. If you have longer sections of wire, twist them together. This will cut down on some of the wire fatigue. For added protection, especially if you plan on giving this to someone who won’t be so gentle with it, use some hot glue to your solder joints.
17. The wires that come already attached to the back of the speaker are pretty flimsy. Use your soldering iron to carefully heat the pads and remove them.
18. Make two small hoops from bare wire
19. Carefully solder the hoops to the back of the speaker where the wires were previously.
20. Put a dab of hot glue over the solder joint on the back of the speakers. Should the hoops get pulled off, there’s a good chance the pads will come off too. The hot glue will help prevent this.
21. Using conductive thread, sew the battery holder to the fabric, connecting to the exposed ends of the corresponding wires. Remember to use a different piece of conductive thread to connect each terminal. Be careful not to sew them too closely together, which can cause your circuit to short after your new friend is all assembled.
22. and 23. Using the conductive thread, repeat the process for the speaker. Be sure to leave room for a conductive patch that you’ll connect to the top pad of the pcb.
24. Use a piece of conductive thread to create a patch from the opposite end of the pcb to the outside of the material.
25. Insert the battery and put a finger on each of the conductive patches. If your circuit is connected properly, you should hear a squeak. If you don’t, you may have inadvertently inserted the battery backwards or you may have a short.
26. If your circuit works, use your non-conductive thread to finish assembling your new friend, filling it with the poly-fiber as you go.
27. If you want to add more patches of conductive thread to create points of varying resistance, do so now.