Calculating length of cloth still on the roll?

General Composites Discussions Composites Talk
#1

:confused: I thought somewhere that it is possible to calculate the amount of cloth still left on the roll by knowing the core diameter, thickness of cloth and the diameter of the cloth still left does anyone know where I can find this calculation? :confused: i was planing on using up all the carbon fiber cloth that i have but things always change and i need to sell them and i need to find out how much i still have left.

thanks for the help :slight_smile:
SXT

#2

No accurate way of measuring.
You can get the circumference of the middle of the material. Then count how many “layers” you have, and multiply by the circumference. That should get you close.

#3

I’ve been trying to figure that out myself! :smiley:

Sell it by the yard (plus add a little extra for insurance) and roll it up onto a paper core that you can get from a shipping box supplier.

#4

note how much you cut every time on the roll’s cardboard :smiley:

#5

And hope there was as much on it as you ordered!

#6

If you knew the weight of the cardbord tube and the weight of your CF per yd you could always weigh it…

#7

weigh the roll.

#8

Thanks for all the feed back and i know i should have track of how much i used but like i said i didnt think i would be selling it this way. anyway…

thats a good idea but i dont know how much to take off for the core tube?

#9

I did some weighing cores awhile back…

3/8" thick 3 3/4" x 61" weighs 4 lbs 13 oz