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300-foot Pocket Tape Measure

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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.
 
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spaceraver11 months ago
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..
CapnChkn2 years ago
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.

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.

Works for me though! Good Job!
zazenergy2 years ago
ha! what on earth are you measuring that's 300ft?

good stuff!
ProfHankD (author)  zazenergy2 years ago
I live on a large lot/mini farm where gardening activities often feel more like terraforming projects. For example, I put in two "little" ponds that are 1/2 acre each. A 300-foot tape measure gets used a lot....
ilpug zazenergy2 years ago
Well, now that he has a tape measure that long, things he couldn't measure before!

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