Re: accurate rods?


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Posted by GES on 2019-01-07 10:20:41 in reply to Re: accurate rods? posted by Ted Shuck on 2019-01-06 11:25:08

The cheapest rod blanks are usually rolled from a single flag that is cut to some specific National secret flag shape to give the rod the behavior they want.

It is highly likely that the line where the rolled flag ends, is the stiffest direction of the blank. The inner flag edge is at a smaller radius, and has almost no effect on the blank stiffness.

So if you set the guides in a line along that outer flag edge,(assuming of course it is even a straight line), one side of the blank is larger in diameter than the opposite side, so the blank is not even left-right symmetrical so it is going to have some sort of a sideways bias to it.

A common method of "spining" a blank ends up identifying the softest, least stiff direction of the blank and uses that as the plane for the guides.

It's so long since I built a rod, that I've forgotten how I used to spine mine, but I believe I used the softest bend plane I could find for the guide plane.

I'm not even going to speculate how various manufacturers do it, because I don't want to accidently reveal somebody or other's company secret, but I bet they all have their secret ways to do it.

These days, I just let Rick Pope's experts build rods that I can afford to buy. And I'm sure there are other good ones too.

George


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