I recently had to cut down a 10' cataract shaft down to 9'. I've documented how easy it was to do by taking pics and descriptions. It took about 10 minutes. Much simpler to do on a cataract shaft than it is to do on a carlisle because the carlisle has an inner sleeve that makes it such that you have to turn down the handles to make them fit back into the shaft.
1) measure 30 times. cut once. I made a mark at 6'2" because the original shaft was 7'2". You want to cut on the handle side because its almost impossible to get the hole diameter and placement on the shaft size. I used a 60 tooth carbide blade it did a nice job but created a lot of dust.
2) I did a quick test cut on the discard handle side to make sure the carbide blade didn't do anything gnarly to the shaft. I was prepared to use a diamond blade from my tilesaw if necessary. fortunately the carbide blade worked fine. Once completing this rough cut, the handle came off and the rest of the blade could be clamped decently for a very clean precise cut.
3) setup for the precise cut.
4) measurement inside the handle from the end of the cut to the counterbalance shaft. I will use this measurement to cut more of the shaft off down to near where the handle/counterbalance goes.
5) cross-section after this cut through the epoxy. You can see the steel slug from the counterbalance in the center of the handle side.
6) using the scrap piece, I set the blade depth such that it would just barely cut through the shaft and not into the handle.
7) I then made a bunch of drop cuts into the material to cut through the fiberglass down to the shaft.
I used a chisel to complete the cut and to "peel back" the fiberglass shaft.
9) you can see I was a bit too aggressive with my cut but this will not affect the integrity of the handle and this will get filled in with epoxy when reassembled on the end of the shaft.
10) yeah!! nice fit. Just needs epoxy!!