How many 300-foot tape measures fit in your pocket and cost under $2?

I had a very nice, somewhat huge, open reel-type 300-foot surveyor's tape measure that worked well until one day it wound funny and I spent a couple of fruitless hours trying to un-jam my $100 measuring investment. I also own an electronic (ultrasonic) tape measure... but that needs a big hard surface to bounce off and only works up to about 30 feet. Actually, you can buy conventional tape measures up to about 25 feet that can be stuffed into a largish pocket... but I want something closer to the size of a 6-foot tape measure. This device is honestly a bit awkward, but it can get the job done and is smaller than an Altoids tin .

I'm sure some readers are thinking "why not just measure what you can with a short tape measure, mark where you stopped, shift the tape measure to there and repeat until the destination, adding the measures to get the total distance?" Glad you asked. Two problems. First, out in the real world, it is hard to be accurate about starting the next measure exactly where the previous one stopped. Second, it is difficult to keep a straight line from start to destination, biasing the result toward overestimation. In summary, accuracy would be much poorer for long distances. Making a calibrated "tape extension" line solves these problems.

Step 1: Materials

Conventional tape measures consist of a tape with calibrated markings spaced at the resolution of the device. For example, a tape measure that reads to a precision of 1/8 inch has the complete length of the tape marked in 1/8 inch increments. To keep accuracy close to precision, the tape is made of a non-stretchy material.

Our "tape" measure also needs to be made of a non-stretchy material, but we can use something much cheaper and more compact than metal, cloth, or fiberglass tape if we don't have to make readable marks on it at the resolution. The trick is to combine a resolution-marked short measuring tape with a less-frequently-marked longer tape or cord -- here we'll use fishing line.

The materials you'll need:

1. An actual tape measure that is way too short. The tiny less-than-$1 ones are usually between 1m and 2m length.

2. A spool of fishing line. To make the line show better for photos, I used 30-pound-test for the unit shown -- don't do that! Cheap 4-pound-test is plenty strong, not very stretchy, fits a much longer length, and is even easier to tie. A spool of 150 yards (450 feet) of 8-pound-test can cost as little as $1.

3. An end for the line. A golf tee or a screw is a good choice if you'll be using this to measure things on the ground; a bent paper clip is a better simulation of the end of a regular tape measure.

If the spool of fishing line you got is one of those flat ones that fits in your pocket, you might be able to bypass step 4 and stow your tape measure within that spool. Otherwise, you'll need to make a spool using either cardboard and scissors or wood and a scroll saw -- as step 4 describes.
<p>I'm having a lot of difficulty tying loops. How do you ensure that your loops are accurate? I'm having difficulty physically tying the loops, but also when I manage, they always end up too short or too long. Do you have a specific method for ensuring your loops turn out right?</p>
Same way you get to Carnegie Hall... practice. ;-)<br>Yeah, it's a pain, but the result is tiny and way cheaper than a long tape measure. Keep in mind that the really important thing is the location of the base of the loop; if you get that right, the errors in loop size don't compound, so a little inconsistency is relatively harmless.<br>
<p>Most fishing line is nylon. Nylon stretches up to about 30% at breaking point. Dacron is about 4%. Spectra, Dyneema or Kevlar has much less stretch, and is stronger than steel. Braided line is easier to handle than monofilament. These are used for fishing, kiteflying and archery bowstrings. And the heavier sizes would be even better. But these are more expensive. If you're just marking off garden rows, anything should be fine. Or if you are just trying to locate survey markers, but for something to make original measurements, I would not trust solutions like these.</p>
<p>True enough, although they don't stretch much at all until you reach a significant fraction of breaking load. Certainly, stretch on the 30 pound test line I used is completely negligible, and it agrees within a few inches with measurements made using a commercial 300-foot fiberglass tape measure, but really light line could be a problem. The nice thing is fishing line doesn't present much wind drag, so it doesn't take much force to pull straight and it's easy to sight along it to be sure it is straight (which is the big problem with things like walking with a calibrated wheel).</p><p>In any case, this is certainly not a measuring method I'd advocate for critical work. It is close enough for things like garden layout or estimating material needs.</p>
Build yourself a two leg walker with a 1 or 2 metre spacing, basically just a big A with a handle on top, which you get by making one leg longer and rounding the end off. Works for me..
Ok, I will accept this as long as tolerance is within .1 ft. In the olden days they had the technique of taking an iron chain with 1 foot lengths, a 3 man crew, and iron pins to mark distances. Later replaced with steel tape pulled to 10 lbs.<br><br>There are formulas in place to adjust for the amount of shrinkage/expansion of the tape due to temperature. Though using a fiberglass tape is common, it's not considered accurate because the cloth stretches.<br><br>Works for me though! Good Job!
ha! what on earth are you measuring that's 300ft? <br /><br />good stuff!
I live on a large lot/mini farm where gardening activities often feel more like terraforming projects. For example, I put in two &quot;little&quot; ponds that are 1/2 acre each. A 300-foot tape measure gets used a lot....
Well, now that he has a tape measure that long, things he couldn't measure before! <br><br>

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