[Whitehorsebob]

I would really like to have a formula( simple is nice) that you can use to know how much backing you can put on to end up with the reel filled properly. So I guess you would have to take line diameter, backing, running, head and then apply that to your spool capacity, width, depth. Anyone know how to do this?

 

[Speyducer]

Spool capacity:

Pi R(1)squared minus Pi R(2)squared times w = spool capacity


given that R(1) is the overall radius of the spool
and R(2) is the radius of the arbor
and w is the width of the spool

and where the sides of the spool are parallel


Mike

 

[Speyducer]

If the sides of the spool are NOT parallel, ie, flared from a narrower width at the arbor to a larger width at the rim of the spool, then you need to add HALF of the difference between the width at the arbor and the width at the rim, adding that amount to the 'w' (width) of the spool. [this again makes an assumption that there is a steady change in spool width from the arbor level to the spool rim]

For more complex cross-sectional areas of the spool, then I'm sure someone with better maths will chirp in!


Mike

 

[Speyducer]

One other thing that occurs to me is that the cross sectional shape of fly lines/heads, and most mono running lines are round and not really deformable in normal use of spooling onto a reel, but that most backing braid is deformable (can be flattened somewhat).

This makes the measurement of the volume of line/head, running line & backing 'interesting'.

In any event, consider that you cannot fill any container completely (leaving absolutely no spaces at all) with ball bearings; there will always be some space between the non-touching parts of adjacent ball bearings! [even with infinitely small ball bearings].

Thus, you cannot actually fill a spool completely with a fly line/head, running line, but the backing will 'bed in' and flatten somewhat as you wind it on.

So all spool capacity will tell you is the maximum you may fill that spool with round-sectioned line, allowing for the spaces between each coil of line, however small that line is.


Mike

 

[SLSS]

My formula would be, Call Poppy at the RedShed. Chances are he knows.

 

[Speyducer]

My formula would be, Call Poppy at the RedShed. Chances are he knows.

Probably so!

There are so many lines/heads out there, of different lengths, grain weights & densities, as well as a mass of different types & diameters of running lines, and of course, many different backing materials, as well as hundreds if not thousands of reels & spools that the good ol' fashioned method of loading on the line/head first, then running line, and then fill to the desired capacity with your backing is possibly the easiest way to go, even if it does mean reversing the whole thing afterwards.


Mike