This one looks like another old Pop Science or Mechanics plan

http://www.homemadetools.net/abrasive-cutoff-machine

This Instructable is similar to the other grinder plan I posted earlier

http://www.instructables.com/id/Angl...-For-Safe-Use/

and one more Instructable for good measure

http://www.instructables.com/id/Cut-...Grinder/#step1

Cheers