From: none@none.com99   
      
   On 12/15/2025 5:10 PM, Jim Wilkins wrote:   
   >   
   >   
   > "Bob La Londe"  wrote in message news:10hq1qh$281ns$1@dont-email.me...   
   >   
   > One thing I drill a lot are holes for hinge pins in molds.  Typically I   
   > drill D, then G, (F would work, but G allows for faster work and still   
   > not bind) and then deburr the hole.   
   >   
   > I was thinking if I grind a 5/16 or 3/8 with a .246 and then .260 step I   
   > could drill and deburr every hole in one setup with out swapping drills.   
   >   
   > I'm about to go swap out the diamond wheel (normally I make carbide   
   > tools) for a white stone and give it a go.   
   >   
   > Can you:   
   >   
   > 1.  Tell me what I'm about to do wrong?   
   > 2.  Off suggestions to make it work better next time?   
   > 3.  Off some guidance other than ask a tool grinding shop to make some   
   > for me?   
   >   
   > I'll stick with stub length screw machine drills of course.   
   >   
   > Bob La Londe   
   > CNC Molds N Stuff   
   >   
   > ---------------------------   
   >   
   > I've made drills to cut various tapers and curves but never a step   
   > drill, and they usually needed a pilot hole.   
      
   I started with a split point screw machine length drill.   
      
   >   
   > Supposedly dry diamond wheels won't burn on steel below a speed   
   > variously given between 3500 and 4500 SFPM. Is your grinder 3 phase?   
      
   Nope.  Just a plane old single phase single speed induction motor.  I   
   did go ahead and use the diamond wheel.  Mostly because I didn't feel   
   like digging for the wheel arbor spanner.   
      
      
   --   
   Bob La Londe   
   CNC Molds N Stuff   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)