I didn't look through these for you, and I forgot what diameter you were looking for. I did a google search for 3/4" bore three groove pulley
https://www.zoro.com/search?category...on%20Equipment
I had a damaged keyway on my tablesaw motor, the same issue as yours...
I ended up welding and filing the damaged part, this took ages, as I'm not much of a welder.
It was very difficult and the filing was slow, nitty gritty hard work on the fingers.
I wouldn't want to do it again.
worn keyway.jpg
Having a guess, I'd say it most likely happened in the first place because the pulley was not drilled on center.
I had to make a jig as I don't have a metal lathe... to mark file and scrape out the bore on center.
I then made a bush/sleeve to fit into the pulley from a hunk of steel
and turned it on the shaft of the motor.
I then cut a keyway into my "new" pulley and made a key.
In the end my key only fit 3/4 into the pulley/shaft and got stuck.
I tried the "persuader" which led to me breaking some of my pulley...quite a lot of cursing happened.
In the end I got the key out with quite a lot of careless angry bashes.
The fit was so tooight that I didn't need a key
So all that extra work of welding and filing the sides of the keyway, and making a key was a waste of time.
Moral of the story...
Check that pulley bore is on center
file.jpgIMG_20170302_095859.jpgIMG_20170305_170945.jpgIMG_20170312_150328.jpgIMG_20170329_185102.jpgIMG_20170329_212003.jpg
Still running perfect, admittedly I don't use the saw all that much.
Good luck
Tom
Install a new key and lightly weld it to the shaft. First grind to make a little room for the weld.