How easy would this be ....to cut a 3 1/2 in. 2 blade spinner and make a 3 blade spinner out of it?
Enlighten me.

that probably wouldn't work,,, the alignment of 2 blades versus 3 are very different... you would need to cut out 3 new openings, not just one....
that would remove too much material.... IMveryHO

Won't work -- buy one

Almost positive that would be impossible to do and still have a functional spinner. Just spend the $$ to buy a new one.

Not very. Another vote for just buying one.

Actually you would only need to cut 2 openings but it would look like crap if it worked at all. Find it difficult to believe worth even trying unless you are really bored. It would also be way out of balance and require even more removed to balance. $$$$ the best here.

DO it on paper, and you`ll see it will become a dangerous part ,and quite likely to explode..Trace your spinner ,then divide the circle into three equal pieces of "pie",mark the current openings ..Find the center. Mark the width of the new blades,"centered", on top of your three marks on your little blue-print..you`ll get a visual like this..

just buy one

just buy 1 m8lol

Ditto - don't do it... will be waaay out of balance, and structurally marginal...