From: none@none.com99   
      
   On 7/28/2024 4:45 PM, Bob La Londe wrote:   
   > I was struggling trying to face some big 304 stainless mold inserts to   
   > length.  1.5" diameter & 1.375" length.  Saw cut of course.  Parting   
   > these off is an exercise in frustration.   
   >   
   > For most stainless work I hand sharpen HSS Cobalt bits, but I was   
   > struggling with my facing tool and to get decent finish would have to   
   > touch it up after ever pass.  I guess I could move the grinder over by   
   > the lathe (cringe) and set a diamond bench stone on the tool cart, but   
   > it was rough.   
   >   
   > Now as some of you know a lot of mini lathe users swear by those little   
   > 21.51 or 21.52 DCMT diamond inserts.  I had one tool with one in a tool   
   > holder and I tried it because nothing else was working for me.  I   
   > finished both ends with a single pass on each end of the last six parts   
   > with one insert that looks the same when I finished as when I started.   
   > After I finished I started going through my box looking to see how many   
   > spares I had.  Ummm. Zero.  There were two broken ones on the head   
   > stock, but no spares.   
   >   
   > The finish is decent.  I just bought some more that are listed as   
   > alloy/stainless.  Also another turning tool, and a boring bar that uses   
   > them as well.  I almost bought a through coolant solid carbide boring   
   > bar too, but that will have to wait until the next job comes in the shop.   
   >   
   > I don't even think I was using it right.  It was a right hand turning   
   > tool and I was just face/plunging it into the saw cut end pushing a cone   
   > off the middle as it finish.  I was amazed at how well it worked with   
   > such an aggressive cut and no chatter.  I even considered turning up the   
   > speed.   
   >   
   >   
      
      
   Its one of those things.  You never see the big boys using those tiny   
   inserts.  They always have these expensive inserts on giant tools that   
   make chips that hit the floor with a clank.  I don't have a giant lathe,   
   but it does weigh a ton (2000lbs).  Its only 3HP, but being a gear head   
   its putting out its full real power (whatever that is) at any speed.  I   
   should be able to take a decent chip and not blow up inserts.  To be   
   fair the lathe does have a coolant system, but I never use it due to the   
   mess.  I tend towards cutting oil.   
      
   I know those little bitty inserts work on mini lathes, but I never   
   really used them much on the PM14x40 except where needed to cut a back   
   clearance or something like that.  I should know better.  They made a   
   bigger depth of cut and bigger feed per rev than other things and there   
   was less heat build up in the part.  No coolant.  Just a few drops of   
   cutting oil.   
      
   I'm going to quit pretending I have a big boy lathe and just go back to   
   everything I learned on the mini lathe that worked.   
      
   P.S.  While I do not recommend them I made a lot of parts on the mini   
   lathe including paid parts.  Not just brass or aluminum either.   
      
      
   --   
   Bob La Londe   
   CNC Molds N Stuff   
      
      
   --   
   This email has been checked for viruses by AVG antivirus software.   
   www.avg.com   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)