Guys no matter what i do on my irs rugrats diff it always comes out feeling ruff when i spin it. I change the balls and sand the pads. I am running the IRS litened pads NOT the ones that are D shaped. What is the proper way to sand them. also how do i know when i am done sanding them. What balls should i be useing.

Thanks for the help

http://www.teamirsrc.com/irs2511.html

These are the pads i am useing