I was thinking about building a spine finder but was told that if blank companies found out that I used one that it invalidate any kind of warranty. So now I'm wondering if they do more harm than good. Do they damage the blank? The person who told me this said he used to use one and broke blanks while using it. I printed the plans from the library, so I think I can build it. I'm just not sure if I should use one or not. Any advise out there?

Steve
I built one using ball bearings like the one in the Library and I did have one of the ball bearing races score a blank and the blank did break. I have since turned a couple of polycabonate inserts for the ball bearings and I have not had a problem since.

You're not going to invalidate any warranty by using a spine finder. Just use some common sense in use and you'll be fine. You don't want to press a blank against a sharp surface and you don't want to put so much bend in the blank that you risk over-stressing it. Most of this is just common sense. Relax and don't worry about it.

And, if you want, you can build a vertical spine finder - put a bearing with a live center straight up in a 2 x 4 and stand the blanks on end and press down on the tip. These work even better. And, you can just set the blank butt on a marble on a hard surface floor and do the same thing. Cheapest spine finder you can make.

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OK... I'm not sure what you mean with the vertical spine finder. What's a bearing with a live center?

I have never damaged a blank using a spine finder. Then again the bearings in the spine finder I have do not have sharp edges - they are beveled.

Spine finders work great, in the early 90s I made one out of a PVC "T" and surplus bearing for less that $10. It is mounted to a bench, out of the way - and still using from time to time. Still, when I do use the spine finder, I still double check for the spine by using my hands.

Lou

Tom, can you please expand on the use of a marble as a spline finder.
I currently just roll them by hand but I would like to hear about another method.
Thanks

You can find an example of a 'live center' spine finder on the Mudhole site. The marble would work on the same premise...allowing the blank to roll freely showing you the prominent side.

Jay

Just set the butt end of the blank down on a glass marble. Now press straight down on the tip (you can even drop a glass shot glass over the tip and press down on that if you want it to be even more free spinning). The outside of the bend that forms is the effective spine.

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That's a great tip Tom, thanks!



Edited 1 time(s). Last edit at 03/25/2005 01:41PM by Mike Anderson.

After you and the wife have a cup of coffee take the two cups and locate spines until the caffeine urge hits again. One round bottom cup on the floor and one inverted over the tip will deflect the blank just like the marble. Order a $ 50 spine finder if you want - someone will be happy and you will support the mail system of your choice. One more thing - after you locate the spine - check the curve of the blanks and if it has a nice gentle one plane curve then you can decide what you really want to do with the dirty cups!

Gon Fishn

Tom..
I can't quite visualize the marble way to find the spine. I'm building three 5 piece rods and would like to find a way to find the spine. Is it possible or is it better to just fit it together so it's straight and then wrap.

How ever you do it I would suggest Before you do any thing - If you know the thread color you are going to use, Wrap the Mail Joints on each section and finish them, First. Then play with them. This way you are protected fron any Splitting at the mail joints when putting pressure on them