Measuring tape fix

I stopped by Daiso at lunch today because who can resist a little bit of cute overload at the Japanese dollar (actually $1.50) store? Check out this little bear measuring tape:

And it is "convenient for the sewing and the body check." Perfect! Now I can do a body check. (click the picture to see it larger, if you can't read the expression at the top).

Since the "Bear's faced measuring tape" is metric I thought I'd keep it in my knitting bag for those times when I'm working on non-US patterns. But in the process of opening the package, which was maybe a little too easy to open compared to the indestructible rhino-proof plastic shells most things are packaged in these days. The measuring tape slipped out of my hands onto the wood floor and...

AAAAAAARGH!!!!!!

Actually the picture doesn't make it look as crazy as it was. Everything scooted under the coffee table, and I tried to find all the parts without knowing what parts I needed to find. The coil had completely "sprung" but I rolled it up and held it together with a clothespin until I could figure out what to do. Miraculously I found everything, including a little tiny spring. Now most people would throw the whole mess in the trash. After all, it was from the dollar $1.50 store. But not me. I'm an engineer. And I'm cheap and don't like to put stuff in landfills, so I fix things. But I didn't have a clue what went where or even how retractable measuring tapes worked. I searched online but found the same answer: throw it away and buy a new one.

So I had a glass of wine to ease my disappointment over the demise of my bear measuring tape and decide if I wanted to accept the challenge of fixing it. Of course I did. I love a mechanical challenge.

I'm going to share my discoveries in case you want to fix your retractable measuring tape instead of chucking it in the trash, because I suspect these little plastic ones have pretty much the same internal design. I figured it couldn't be too complex given that it was so inexpensive. I also figured that every notch and hole and piece of plastic served a purpose. I just had to figure out what went where. The only thing that was partially intact after the crash was the tape; it was still mostly wound around the outside of the black wheel, so that meant the coil had to go on the inside.

I was almost correct in the above picture. It turned out I had the assembly upside down but in this view, you can see how one end of the coil fits into the notched, plastic center post. There are four notches cut into the sides of the plastic wheel: the looped end of the tape slips onto the two notches that are closest together and the other end of the coil is secured in the other two notches. When the wheel is wound, the coil, being secured now at both ends, tightens and stores energy. I found that the way to get the tape onto the wheel was to wind the wheel so that the coil tightens and at the same time, guide the tape around the outside. But that's not all. When the coil is as tight as it will go, carefully undo the tape from the wheel but leave the looped end attached. Then you reverse the direction of the wheel (slowly!) and the tape will wind back onto the wheel in the opposite direction as the coil unwinds. When all of the tape is reeled in, the coil is no longer fully wound and ready to fly off. But when you pull the tape the coil winds up; release the tape and the coil reels in the tape again.

The next part was figuring out how the middle button (bear's nose) fit. The tiny spring in the center post was a key piece and made me realize I had everything upside down. It's correct in the above picture. See those plastic tabs in the inside of the wheel? Those are the "brakes" that are disengaged when the button is pressed. This is also why these type of measuring tapes go click-click-click when you don't depress the button.

So there you go. My little bear measuring tape is happy again and I solved a puzzle, saved a bit of plastic and metal from the dump, and best of all I have a cute tape measure for my knitting bag.

And if you're wondering, the bear measuring tapes also come in blue and yellow. I didn't see any other animals, just bears.