Agree with Britt’s advice and comments.
On your last response you mentioned “I can afford a laser device to FLO shafts but not the machine for measuring frequency”.
When you FLO a graphite shaft using a laser device you’ll get two opposite planes (four spots at 90º from each other). One of them will be the neutral plane and the other the spine. The only way to understand which one is what, is by using a frequency machine. The spine will be the one with a higher frequency (stiffest) and the neutral will have a lower frequency.
You will have to start by the frequency machine (there are affordable ones out there for 260$ that work great) that will allow you to build sets with consistent butt flex between clubs and for example compare the flex of two driver shafts… Later on, you could buy the laser device and use it in combination with the machine.
If you like the matter and are curious about the technical behind all of this, you should visit Dave Tutelman’s site and spend some time reading his interesting articles.
Have a great game.