No Lathe, No Milling Machine, No Problem

Step 8: Grind flats

My grinding wheel is mounted on my radial arm saw.  That means I can slide my mandrel holding jig under the grinding wheel.  It also means I can lower the grinding wheel incrementally.  I ground all three flats to just a bit less depth than I wanted so the last "cuts" could be very light.  This was to insure that each of the final cuts would not be affected to any degree by part of the grinding wheel wearing away during heavier cutting on previous flats.  The hex nut on the mandrel made a handy guide for rotating the mandrel 120 degrees between the three flats.  To grind I simply slid the mandrel and its supports laterally toward the grinding wheel.

Comments

[HadesHubs]

Excellent solution to this problem.  I have an arbor that actually twisted off from heavy use with a 4" blade.  My small lathe was not solid enough to turn the hard section of the sleeve I welded back on.  This little jig is the answer, and using my radial arm saw will act as a surface grinder to return the shank back to center balance.  Thanks a million for the ideas~!

[Phil B]

Thank you for commenting.  I had hoped someone might be able to use some general principles from this Instructable.  I never guessed someone would need to do the same job.  I hope it works out well for you.