Specs for DIY spine tester?

[Wheels2]

I am looking at building my own spine tester.
How far apart should I make the blocks?  26" or 28"
What weight is correct for each span distance?
What is the formula for converting a digital reading to poundage?  (.500 + ?#)

Thanks,

[Matty]

Do a google search. There's quite a few good builds out there.
I think there may be one in our "how to" section take a peek there. Either way to answer your question.
26" and 2#

[Wheels2]

I got the answer on another sight.  Based on the calculation equasion, the 26" span and 2# weight is the way to go.
The 28" span and 1.94# requires constant reference to a chart as the math is not as neat and I have yet to identify the required constant.

[Stumpkiller]

I built mine into the edge of a shelf over one of my workbenchs with two dowels 26" apart and a 2# weight.

 

 

 

Rose City has a chart you can download with the AMO deflections.

 

[Fletcher]

The chart above is the easy way to go to convert deflection to spine.  The formula is: 26 divided by the deflection in inches = spine.  Example, 26/.500=52#

[BAPilot2]

Stumpkiller,

Cool idea!!!  I may have to steal that one and call it my own!
Nice set up.

[chall]

Good info thanks for the post