Let's Make Robots!


IBS-Wormy.bas3.34 KB

Last Update: 3-Aug-2011 :

Finished assembly. Updated board photos and added few more.

Meet IBS-Wormy! This is a simple bot for my baby-daughter to play with. And I hope she'll like it :)

IBS stands for "Isotope's Baby Series". I'm planning to build more bots under this tag in future.

Wormy has only one sensor so far - a tilt switch. By sensing changes in sensor's state bot knows if it is being "played" with, and starts wigling like a worm. The body is four segments of PVC pipe linked togeather with three servos which create wigling motions. It has LED eyes for blinky stuff and a speaker to make some noises. All it is enclosed in funny phonendoscope cover made of soft fabric.

This is what I did start with:

The pipe was cut into segments. This particular PVC pipe was quite heavy, so I did a bunch of perforations to make it lighter.

  Mounting of servos was a little bit tricky, as I wanted as sturdy link as possible. So, each servo had to be bolted by two bolts at each side. Top connections was somewhat straightforward, but for the bottom ones I had to design a little mounting plate which is bolted to servo bottom by four screws that hold the servo togeather. I have used 3mm thick Sintra. I found this material really handy for construction. It is soft enough to be cut by utility knife or even scissors, but strong enough for most robot parts.




The links turned out even better than I thought!

The eyes. Wormy looks like a Terminator now :)

This comprises the hardware part.

Wormy has a Picaxe 18X as brain. Full electronic parts list:

  • C1                    10uF Electrolytic Capacitor
  • IC1                   PICAXE-18X
  • J1                    Basic Servo
  • J2                    Basic Servo
  • J3                    Basic Servo
  • LED1               Red LED - 5mm
  • LED2               Red LED - 5mm
  • Programming jack   Stereo Jack (TRS) 3.5mm
  • R1                 4.7kΩ Resistor
  • R2                 22kΩ Resistor
  • R3                 10kΩ Resistor
  • R4                 330Ω Resistor
  • R5                 330Ω Resistor
  • R6                 330Ω Resistor
  • R7                 68Ω Resistor
  • R8                1kΩ Resistor
  • R9                10kΩ Resistor
  • S1                 Mechanical (ball) Tilt Switch
  • SPKR1           Loudspeaker 8 Ohm
  • VCC1             4AA Battery Holder
  • Power switch (not on schematic) Slide type DPDT

The electronic schematics for Wormy (including LEDs and Speaker to be added in future. Made in Fritzing) is:

And this is how my board looks:

Circuit board is located in the first segment (head). Battery pack and power switch in last one (tail).

Assembled wormy w/o skin:

And with skin:

An this is how I program it :D          (BTW, The code is attached)


  1. Video shows Wormy on it's first test.
  2. Wormy is assembled and ready :)
  3. [coming soon] This video should actually show wormy doing what it was made for: playing with my baby, should she like it  :D

This is it. I hope you did like my Wormy! :D

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Thanks for mentioning this, I did try this now, and it is really hard to get pinched unless you do put your fingers in between sections intensionally and in proper places. And even though the force is nowhere near to be damaging. All I felt was little pressure, that was it. Anyway, this robot will be played with under constant control. :)

Isotope, this is a really cool configuration!  Kinda freaky how it moves, should be entertaining. 

Does the "skin" help prevent litle fingers getting pinched?

Thank you all for your feedback! :) I do really appreciate it!

@ignoblegnome: I hope too :) She is away now with her mother visiting her granny, so I hope she will like it when she is back :)) In the worst case it was fun at least for me to build this robot :)))

@OddBot: These servo savers look like a good solution and are pretty cheap in general, so I think I will consider using them in my future projects involving servo abuse :))) Thanks!

@Dan M: Yeah, that was a dillema for me actually. Even though I marked this project as done, I still think of adding a vibro to the project, that is why at this point I decided to go with conventional output for LED eyes and spare PWM pin (which 18x has only one) for possible future vibro motor control. Anyway my daughter has to judge the robot first :) And if she does not like it, I might go ahead and swap LED output with PWM pin. Thanks for your constant attention! You do have a lot of experience to share!

Cool project. I hope you daughter likes it!

Fantastic work as always, isotope :D

I Like it... very neat and simple..

I love this one! Now I know what to do with these pipes!!

Love it! However, you might want to change the name. IBS also stands for 'Irritable Bowel Syndrome'!  ; j

Thanks a lot :) I think I will leave it as is, so be there a positive alternative for that abbreviation ;)

Very creative .