Sing-A-Ma-Jig is a creepy toy!

by Jimmie on February 10, 2011

IMG_0357 Holy crap, I can’t believe they make this thing for kids! Even without the molestache(which I printed out), it’s still creepy.  It’s also quite ripe for bending. The thing is called a Sing-A-Ma-Jig, and I got mine at target while in NYC a few weeks back. I even opened it up that night and just used my fingers to see if it was bendable, and it is indeed.

This post is something that should have been posted yesterday, but I sort of started hanging out with my roommates. Then beers got involved, and then motivation was thoroughly lost. The previous two days was a combination of sleep deprivation, workshop preparation, visiting of friends, and travel. Seriously, I didn’t do anything creative for those two days, and I was running on only a few hours of sleep a night. That really tends to sap my creative energy. I’ll post a few projects after the month is over to make up for it.

This post is about the exploration of the toy, and how I go about finding fun points to bend. I made a quick video, and I also uploaded a bunch of pics to my Flickr. Behold, the first video:

This thing is fun right away. Really sensitive to touch, which means that it will be easy to bend.

This was actually fairly easy to take apart, but you do have to snip the threads at the top of the battery compartment. Behind the head you’ll find the two screws you’ll need to remove the electronics:

IMG_0419 Those two holes at the top right and left are what you are looking for. Next there are four on the front of the case you’ll have to remove:

IMG_0420 I’ve removed the four at this point. The plastic piece on top can be taken off as a single piece. You’ll then be left with the speaker to deal with:

IMG_0421 Save that metal bar in the middle, otherwise you won’t be able to keep the strange mouth movement. Honestly, the mouth movement is half of what makes this thing creepy.

IMG_0423 I’ve removed the hot glue that covered most of the electronics so that I can give it the bad touch. For interesting toys, I draw a map of the circuit.


This is my note page filled with info. At the time of the video, only things above “Bends” were really written down. Then the second half has the info for bend point one.

IMG_0439 I found that bend point one responded really well with a 1Meg pot. Point1 is connected to the middle position of the pot, with +3V going to the left position, and GND going to the right position. I also found that it responded well with a photo-resistor, and I used a 2k-2M one. I generally tune my toys as well, which is what the 22k resistors are about.

What I mean by tuning, is that I try and find both the high and low end that the toy crashes. I start with a large pot (like 1 Meg), and find that spot. I then remove the pot and measure it with a multimeter. Then I lower to an appropriate pot and continue to fine tune it. If the crash value is 10k, I’m not going to use a 500k, but a 100k or 50k. In this case I got +57k and -39k, so I used a 100k pot. Then I found the value of +-24k. The closest resistor value I had was 22k, so 22k it was.

I’ll put touch contacts in behind the 22k resistors, as going below that doesn’t help at all. I’ll also get up the next post fairly shortly, as I’ve already completed it. Like I said, this should have been posted last night.

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Triggering the Sing-A-Ma-Jig with a 555
February 10, 2011 at 21:16

{ 10 comments… read them below or add one }

1 Dave Dalton January 24, 2012 at 20:52


We have a pile of these disturbing things.
And circuit bending jam night at Hammerspace is in the works!

Thanks for the reference material.
My urge to dismember is rising!

2 phooky February 13, 2012 at 02:05

We’ve had one of these little terror vortexes on the table at NYCR all week. You forgot to mention its creepiest feature: IT HAS TEETH.

Lids have been flipping all week over here.

3 lesley August 18, 2012 at 15:08

I like this toy – and the molestache…so I’m posting my test comment here.

4 jayne October 4, 2012 at 03:30

i love that sing a ma jig make a videio of it singing yankee doodle low pich and whith the 555 timer chip

5 jayne October 4, 2012 at 03:32

yankee doodle went to town riding on a pony stuck a fefer in his hat and caled it macarony……………………………………………………………………………………fevy well

6 jayne October 4, 2012 at 12:28

i rely like it

7 roy October 18, 2012 at 12:46

love it

8 sly October 19, 2012 at 12:49

Funny but creepy

9 jayne October 24, 2012 at 12:10


10 Frisky October 27, 2012 at 14:03


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