# Atlas 618-Cutting Results



## CAW (Mar 7, 2014)

I have problems with the quality of the cut on my lathe.  I turn primarily low carbon (1018) steel or aluminum for turning on my lathe.  I normally use the lowest speed with the bull gear engaged.  I used HSS index bits on an A2Z tool post.  

My cuts leave fine lines like on a phonograph records; I am unable to get a real smooth cut unless I file or sandpaper the cut.  I have used faster speeds, but it does not seem to make a difference.  I have used larger lathes in the past and the cuts were very smooth.

My observation is that HSS index bits produce a better cut than carbide index bits; at least on my lathe.

Any suggestions on how to obtain a smooth or finish cut on my lathe?

Curtis


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## David S (Mar 7, 2014)

Curtis not sure quite what you are describing.  Is it the fine feed of the tool cutter, or more like some sort of vibration superimposed on the cut?  Is the lathe well secured to the bench?  And how about any belt vibration?

David


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## CAW (Mar 7, 2014)

A way to describe it is that the cut looks like very fine threads.  Like the lines on a 45 rpm record.


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## VSAncona (Mar 7, 2014)

Did you try honing a small radius on the tip of the tool?

Vince


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## David S (Mar 7, 2014)

Are you using the powered long feed?  If so what is it set to.  I normally do my finish cut on aluminum by hand with a sort of rounded nose HSS lathe tool.

David


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## mattthemuppet2 (Mar 7, 2014)

ditto what the others have said - if the HSS tool has a very sharp point you'll need a high spindle speed and very low longitudinal feed with just a skim cut to get a smooth finish. WD40 helps too, stops the tool from digging in. You can get a smooth finish, just takes a lot longer. Or you could grind a small radius on the nose of the tool or even use a dedicated round nose finishing tool. You should be able to find some combination that works with a bit of trial and error.


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## francist (Mar 7, 2014)

Maybe have a close look (magnifier) at your cutting edge. You are using the exact same machine as I am with a very similar tool setup. I'm also using HSS but not inserts. Very recently my cuts were exactly as you describe -- very very fine like a record groove. Took a close look at my edge and there was a tiny chip off it right at the cutting radius. I took a pass or two on the grinder to refresh the edge, then honed it like I always do. Major difference, nice and smooth cuts again.

I'd also look at your feed and speed rates as others have suggested -- you should able to run faster than the lowest speed all the time which might improve things for you.
-frank


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## docn8as (Mar 8, 2014)

THE  WAY  TO  REMOVE  FEED  LINES  IS  WITH A CUTTER  TIP LARGER  THAN THE FEED LINES ...SEVERLA  WAYS TO  DO  THIS  ...\ SET A  KNIFE  EDGE  TOOL (  LIKE A  SHEEP FOOT  BLADE   OR LIKE A  CARBIDE TIP A STYLE ( BUT USE  hIGH  SPEED) 
 SET THIS  AS  FLAT AS  POSSIBLE  W; OUT  CHATTER  TAKING A  3  THOU OR  SO  DOC..
  NEXT  GRIND A FLAT  NOSE  TOOL , FULL WIDTH BUT  W/ FORNT A7 SIDE CLEARANCE  &  FRONT TO  BACK  CLEARANCE ...SET  THSI A S  FLAT AS  POSSIBLE  AGAINN 3 THOU DOC 
  GRIND A  SHEAR  BIT ...60 DEG  ANGLE  RUNNING  SW X NE W/ CLEARANCE IN FRONT ..SET  THE BIT  SO THE WORK IS  NEAR  CENTER  ,,THIS  ANGLE  CUT ERASES  THE  FEED  LINES ....& GIVES A  DEAD  SMOOTH  FINISH    AGAN UNDER  3 THOU DOC ......A 1/32 FLAT  ON THE  END  OF TEH  BIT  WORKS  BETTER  THAN A  LARGE  RADIUS  , BUT NOT AS  WELL AS  THE  OTHER  WAYS     THE ROUND  NOSE  DOES NOT  CUT  ACROSS THE  LINES  UNLESS A  DEEP CUT  IS  MADE OR A HORRENDOUSLY  LARGE  CHATTERING  RADIUS  IS  USED ......
ALL THE  ABOVE  REFERS  TO  1018 STEEL 
   BEST  WISHES 
DOC 
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