Deflection board

Just got a golfsmith deflection board and does anyone knows how far the bottom of the shaft needs to be supported to get an accurate reading of the shafts stiffness. From the pictures you can see that the tubing holding the shaft is only about 5 inches. I can put a clamp below or a U shape metal inside the black tubing.

Pretty sure it's similar to Golfworks'

https://www.golfworks.com/images/art/GSDB.pdf

So I just need to add my U shape metal piece inside the black tubing. What would be the total measurement from the end of the tubing. The bottom end of the grip or 12 inches total from the end of the grip.

Similar to this I would say: https://www.youtube.com/watch?v=J9ugEt3MbkY

From the looks of your pic it looks like 5 inches.(bottom end of the grip)

Although not obsolete the shaft deflection board is the father of EI bend profiles and zone frequency measurements
http://fit2score.com/blog/?cat=10

http://fit2score.com/blog/wp-content...gAnimation.gif

thanks and that is what i was doing to measure. Just doing this for my own fun with my own shafts and the golfworks comes with a smaller square tube and seems about 12 inches at the most. Could not find any info on that model on any website and post the question here.