I am building a 4 piece fly rod. I am at the point of trying to align the pieces to find the axis for the guides. What process do you use to find the axis when dealing with multiple piece rods? Also, how big/small of a loop is acceptable for the tip when rotating the blank?

Ed,
If you want to get perfect alignment, just use the normal process for finding the spine of that blank section . Mark the spine and then just align the blank sections to line up with all of the spine marking in line.
But, some folks use the contra alignment. Particularly with a 4 piece blank, they alternate the spine markings and orientation for every other section. i.e. spine up, spine down, spine up, spine down. This alignment will result in a completed rod with close to 0 spine overall.

A 0 diameter loop of the tip is acceptable. But, even a 3-4 inch look can certainly be used, but perhaps not as well as if the loop was closer to 0 inches / mm.

What exactly IS "the axis of a blank" and how can you tell when you have found it?

Phil,
My guess is that Ed is really talking about the "Spine" of the blank.

Take care

I read a lot of these posts, just trying to figure out the language of rod building.

The original post in this thread included, "Also, how big/small of a loop is acceptable for the tip when rotating the blank?"

One of the answers was, "A 0 diameter loop of the tip is acceptable. But, even a 3-4 inch look can certainly be used, but perhaps not as well as if the loop was closer to 0 inches / mm."

I have no clue what the question or the answer refers to.

An explanation - in just conversational terms- would be most helpful to me.

Thanks-

Tom, i,ve been building rods off and on for 60 years and i have no idea either..lol.

Tom:

I'm just guessing here but assume a multiple section fly rod. Take each section in turn, mount the butt end in a power wrapper with only one support located very close to the wrapper's jaws. Rotate the section slowly and observe the tip end move in a circle or loop. The straighter the section the smaller the circle or loop. You can see the same thing happen by rolling a section with only the last 2 or so inches of the butt section supported by the edge of a table. Neither method is especially accurate but beats eye balling a blank section and can be useful for those wishing to build on the straightest axis by marking the point at which the tip is the highest (the inside of the curve) or the lowest (the outside of the curve).

Hello Tom.

There is a glossary at the top of the page, it might help with some "conversational terms".

Good Luck.

Tight Wraps & Tighter Lines.

Bob,

New Bern, NC.

Ed,
I only build 4 piece fly rods - and I do spine all of them. I even spine blanks for new builders who buy CTS blanks from me before i ship them.
First I spine the tip section (4th section )- mark it with a grease pencil.
Then spine the 3rd section.
Assuming that your blank has a logo on the butt - that is already spined. Just connect the butt section to the 2nd section and spine it together.
If your blank has no logo - not to worry - just assemble the S1 and S2 and spine them as one.
Now assemble the 4 pieces - butt on the floor - and flex to spine it.
If all your marks are still in the center of the blank you are good to go.
If they are off to the side - make new marks that are in the center. Don't forget to erase the old marks.

What is important - if you like to spine a blank - is that the assembled blank is spined.
Herb
CTS

I prefer to make the straightest axis of each blank section and then assemble them and build that way.

............

I know the spine is different from the straightest axis. I am attempting to find the straightest axis of the four pieces combined. I mounted the butt section in the rod lathe and supported it close to the lathe. I set up a vertical piece of graph paper at the end of the butt section, for reference. I rotated the butt section and found the straightest axis. I then attached the second section, rotated it with respect to the butt section, and rotated both together while watching the end of the second section to find the straightest axis with the two combined. And so on with the next two sections. I try to get the tightest circle with all pieces together. I was curious to see how others did this task and to see if my logic is flawed or excessive.

I roll them on a flat surface like a table, or countertop, at the straightest axis the top will be perfectly flat, or lifted off the surface slightly, the tip will appear to swing right, or left off straight if moved off this point, this works on blanks in any configuration. One piece surf blanks take up all the wood floor in my kitchen/family room.

Ed Kramer Wrote:
-------------------------------------------------------
> I know the spine is different from the straightest
> axis. I am attempting to find the straightest
> axis of the four pieces combined. I mounted the
> butt section in the rod lathe and supported it
> close to the lathe. I set up a vertical piece of
> graph paper at the end of the butt section, for
> reference. I rotated the butt section and found
> the straightest axis. I then attached the second
> section, rotated it with respect to the butt
> section, and rotated both together while watching
> the end of the second section to find the
> straightest axis with the two combined. And so on
> with the next two sections. I try to get the
> tightest circle with all pieces together. I was
> curious to see how others did this task and to see
> if my logic is flawed or excessive.

Your method is the same one I use and we have done an article to that effect in the magazine. It'll get you what you want.

..........

Hello All.

I know of two articles in RodMaker about "Straightest Axis" and they are Vol-11, issue-5, page-14 "Straightest Axis, How To Find It and Why It Makes Sense" and Vol-20, Issue-4, Page-26 "Straightest Axis, Why Build On It?".

Is this what you are looking for?

I don't do rods with more than two pieces (and of those most are removable butts), so I just do the roll method.

Hope this is helpful.

Tight Wraps & Tighter Lines.

Bob,

New Bern, NC.

Thanks to all for the responses. This answers my questions.

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