Before sending this thread over to the "How To - Resources" board, I figured to first post it on the PowWow for yer general amusement
For us woodie arrow shooters it's pretty important to understand wood shaft spine in order to sort out shafts and find all the proper shaft sides that'll allow the proper stiffness for our bow(s). If ya buy dozens of shafts at a time then this tool is even more of a must-have.
A pine board for the base, a digital dial indicator, coupla hanger hooks for the shaft/arrow, a 2lb weight - these are the basics, but when you get to stick it all together you'll find other parts might be needed ... as I did. The big (and only) expense for me was the dial indicator that was less than $23 off the amazonia market place. The rest I more or less had - or found.
This is a hanger spine meter that needs to get stuck to a wall or shelf or table edge. Legs could be added to make it a stand-alone if need be.
The digital dial indicator needed a bit of prepping - the back cover is removed and the indicator shaft spring is removed so that its tension doesn't add to the metering. The back plate of the indicator was metal, with a funky "eye" hook that I removed. The block pine that the indicator sits on has a 3/4"x 3/8" disc magnet that I epoxied flush, and that's what Powerfully holds on the indicator and allows adjustments to it. The indicator shaft had a screw-in point that I removed so that the flat end would have more purchase as it rested on a shaft/arrow.
The main thing is that woodie shafts/arrows need to be spined on their 26" length and that's where the hooks are screwed into the base board. Moving the hooks to a 28" length and adjusting the weight from 2lbs to 1.94lbs allows for metering carbons and aluminums (I used bird shot, so it's easy to adjust the weight - but heck, I don't mess with them carbonium or alloy arras any more
)
That's about it. Works just fine for me.