You may not have expected this as a response!
I'm a professional knife maker and have been making knives for almost 10 years. I have two high dollar knife grinders that cost upwards of 2 grand.
But, when it comes time to shape handle material, I use files.
Attach the handles to the knife, stick the blade in a vise, and shape with FILES!
One little "Oops!" on the grinder, and a whole lot of work its ruined.
Files do EXACTLY the work you want them to, remove EXACTLY the amount of material you want, and helps you to keep opposite sites equal.
You also don't run the risk of over-heating your handle material.
Give it a try - you might like it!