Cut to Center - not

[Bladepeek]

Does anyone have a really clean, scientific method for determining the distance from center? So far, I've been visually centering the string on the belly of the limbs, then carefully sighting down directly over the string and taking a WAG (wise, all-knowing guess?). Sort of like "measure with a micrometer, mark with a crayon and cut with an ax".

1/16th of an inch difference from center makes a difference in Stu Miller's calculator, so my + - 1/8" guess is a bit ragged to me.

[Looper]

Yeah, but it's complicated. You want me to do a "how to"?

[Dogboy900]

I picked up a cheap plastic set of vernier calipers, then followed the method in Stu's instructions as below.

I lay the bow on something flat, measure the thickest part of the bow, then measure from the flat surface to the sight window using vernier calipers, then measure the strike plate once again using the verniers, and add that on.
Mostly use the wire that slides out of the bottom of the verniers for the measurements.

Hope that made sense and helps  

[Looper]

Okay, here's an easy way. I was kidding earlier about it being complicated.

First get yourself a ruler. Make sure it is marked in 1/16" increments. Then grab your bow.

Hold the bow with the back facing you and position the ruler like so:  

What you are looking for are two things. The centerpoint of the riser, and the distance from the centerpoint to the shelf.

In this picture you can see that the overall width of the bow is 1-1/8" wide. That would make the centerpoint 9/16" from the left edge.  

Now notice that the edge of the shelf is at 7/8".

Subtract 9/16" from 7/8" and you get 5/16", which is the distance from center this bow is cut (with the strike plate).

Note that if your bow has a lot of contour around the handle, you might need to lay it on a table and use an additional flat edge to find the overall width.

[Bladepeek]

Looper, nice illustration and I think that would be better than working from the belly with the inherent angle deviation errors.

Dogboy900, the boy engineer in me makes me want to try your method.

Matter of fact, I think I will measure several of my bows using both methods and see how close they come to each other. Both methods beat my way by a furlong (however far that is).

Thanks guys.

[TxAg]

I vote for asking the bowyer

[Bladepeek]

Now why would you want to do things the easy way?

Besides, inquiring minds want to know (even if we don't understand all that we know)  

[Sixby]

You have to use two rules, one short and one long. The long one you center on the limbs. Dead cemter on each limb. Then you measure over to the sight window with the other one. Since risers may or may not be centered to the limb depending on how the bowyer builds it you have to do it this way to find where true center is.
Also it helps to have the string centering the limbs. Again depending on the quality of the build and the builder. I have seen more than a few bows that the string did not center the exact center of the limbs./GRRRRRR.

God bless and good luck, Steve

[SaltyDawg]

Here ya go.

This works well.

 

Rick