How to best measure Rope....Make a handy chart for yourself.

[Chuck]

I am re posting this from another topic so its easy for folks to find should they need it.

 

Its very difficult to measure rope using any method.  That technique of wrapping it around a dowel is not very good either.  There is too much variation depending on how tightly you wrap it.  It would flatten out the rope and distort it.   It is also hard to get a consistent space next to each revolution around the dowel.   One may be closer than another.  It may be squishing the wrap next to it etc.  If you did it ten times or asked two different people to measure the same rope that way you would never get the same measurement.  It may be close but you would be surprised.

 

Thankfully You would also be surprised how sophisticated our software has become.   I use Corel Draw and Illustrator all of the time.   When you draw a line in either program its thickness is measured in points.  Lucky for us there are many conversion tables and apps that will convert points to inches.....or metric.  Whichever you prefer.

 

If you know that a line you need is .018" and you want to see what that exact thickness or diameter in our case is....then do the conversion.  

 

.018" is equal to 1.296 points.   If you create a line in any of those programs and make it 1.296 points thick.....its pretty darn accurate.  You will know what a .018 size rope should be....

 

Here is a chart I have on my site for folks that need a more visual way to see what these sizes actually look like. 

 

http://www.syrenship...pesizechart.pdf

 

Its pretty darn on the money and I have one close by at all times when I make my rope.  Its leaps and bounds the more accurate way with technology to measure rope accurately.   Also set your printer for the highest quality print job........

 

Maybe when I get some time I will create a new chart which contains even more size variations.  Maybe every .005" or something.  Here is a good inches to points conversion calculator.   Its the one I use.

 

http://www.thecalcul...s-to-inches.php

 

Chuck

[Ponto]

Love it,.... simplicity in form yet the differences (however minute) are readily discernible by eye ----- and I never would have thought it!  The proof is in the chart and thanks for that................

 

 

JP

[Modeler12]

Sorry Chuck, but I still think that a much simpler way is to measure the thickness of the thread or rope in question at several places along its length. I use a dial indicating pair of calipers that read to within .001 inch and have generally found very little variations within samples of thread and rope (if made correctly and of uniform shape).

I compared that against the winding method you mentioned and found no significant differences.

 

If there were to be a variation of a mil or two, would that matter????

My little rope rack is marked with the 'nominal' and I don't worry about the details.