Cutting threads on a lathe help

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Freshly sharpened high speed steel.60° point.1mm below center.Bit is "square" to the work.Cutting oil and about 30-45rpm.Threads coming out "furry" and far from clean.Only taking .005" cuts.Help?Miller Dynasty 200DXMiller Spectrum 250DMiller Millermatic 200Bunch of old blue dinosaurs....
Reply:bit should be on center,  compound set at 30 degrees off perpendiular.  advance with the compound so that only one side of bit is cutting.   First few cuts ten thou and when you get down do a 3 thou advance and then take a free cut once and awhile.   Some set the compound a degree or half a degree off to stop the bit dragging on the right hand side.Some grades of steel are not as easily machineable.this guy covers everything !![ame]http://www.youtube.com/watch?v=5-bTfflIPlc[/ame]Last edited by lotechman; 08-19-2012 at 10:03 PM.
Reply:Thanks for the video. Everything he's done I have done.What I'm not getting is chip separation from a mild steel or aluminum bar.Miller Dynasty 200DXMiller Spectrum 250DMiller Millermatic 200Bunch of old blue dinosaurs....
Reply:For aluminum use turpentine or mineral spirts..  I use WD40  Of course positive rake as much as 30 degrees on bit is required.   To finish the thread I advance the cross slide in about one thou per trip so that the tool finishes off taking a dragging cut on both sides of the thread.  Also Unified threads have a small radius at the root so the tool can be dress off a bit.  For a good form I often sharpen up my bit when I am about 3/4 done and continue on.  It is a bother to reset everything but it is quick once you understand what is happening.   Many confuse on the thread dial.  The numbers represent inches.  Imagine a ruler travelling along your threaded piece.  You can't see that imaginary ruler but your thread dial tells you where the one inch marks are.  if you are cutting 8 threads per inch then you can pick up on the half marks since there is a whole thread at 1.5 and 2.5 and 3.5 etc.
Reply:do you have any rake ground on your cutter?tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Like anythig else results will vary gratly dependent on equipment, I've alwas been disappointed with my results using a light duty lathe with hhs ground tools, i would cut to 80% thread form and finish with a die nut.  Once i had a rigid machine with laydown threading inserts then it was possible to thread with acceptable results.  My only advise would be to increase your rpm, try 150, if you are comfortable with the tool speed, you may see an improvment in finish.You didnt mention what diameter you are turning, smaller diamerters tend to deflect under the cut.Briggs weldnpower 225/210/cvLn-25 suitcaseMillermatic 130