Re: HSS vs TCT


<jontom_1uk@xxxxxxxxxxx> wrote in message
news:1157034347.672614.165200@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

zedbert@xxxxxxxxx wrote:

Jim, do the carbon tools give a better finish than the HSS then? Don't
they need to be sharpened more often?

Thanks for the link & suggestion of the Hemmingway grinder guys, but
seriously, I don't intend to pay that much for my next car!

I've seen a pic of a metal template that is made with the front, side
etc. clearance angles, on each side. Does anyone use one of these for
free-hand grinding?

Ed, I second what Dave has said, just grind them freehand you will soon
get the hang of it. The angles do not have to be within a couple of
minutes or anything in fact you will soon change them slightly
depending on how the material cuts. A couple of pieces of 3/8" HSS will
only cost a few pounds grind them up and see how they work, if they
don't cut try again. It really is cheap training and once you have
mastered the technique you will never be without the right tool again.

I don't believe there is a "best" tool that will produce a superb
finish on all occaisions and I've found that by experimenting with
speeds/feeds/depth of cut etc you can make most types of tool do a
reasonable job. I did at the outset spend a lot of money trying all
sorts of "magic" tools, it didn't help my turning at all just kept the
tool dealers in caviar. Of course if you are sharpening end mills etc
then a decent tool grinder is essential, for normal lathe tools I find
an off-hand grinder and a couple of hours invested in practise sorts
out most problems. A fine diamond file or stone allows me to dress the
edge of a finishing tool when necessary. To rough things out with heavy
cuts I use tipped tools to stop me having to sharpen regularly, it's
really for my convienience not for the quality of the cut.

Best regards

Keith

This is very much my experience too -

It doesn't take long to get the hang of off-hand grinding HSS tool bits. As
Keith says, just a few hours and you can get on top of it.

I've been working some ally bar in the lathe and needed a really top dollar
finish - the tool I used? A re-ground letter stamp! Just ground to a small
radius round nose and then honed. It chattered with a "heavy" cut but a
very light cut and it produced a mirror finish. The only reason I bought
some carbide tipped tools was I had a few pulleys to cut from Cast iron bar
and HSS runs out of steam too quickly on the roughing cuts. I've also
discovered that you still need to revert to HSS for finishing cuts.

You also need to make sure that that everything is a rigid as possible,
parting off usually exposes weaknesses in the set up.

Getting a good finish is just practice and experiment. Use known "good"
materials to remove at least one variable. I have access to some scrap
materials (ie the corroded and grotty) and its typically unusable. Harold
Hall recommends free-cutting steels for many components, because they are
easier for novices like me to work with.

Nothing like getting stuck into a piece of aluminium bar and finding there
was a cylinder jacket hidden inside!

Steve



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Relevant Pages

  • Re: HSS vs TCT
    ... Of course if you are sharpening end mills etc ... then a decent tool grinder is essential, for normal lathe tools I find ... It doesn't take long to get the hang of off-hand grinding HSS tool bits. ... Cast iron bar and HSS runs out of steam too quickly on the roughing cuts. ...
    (uk.rec.models.engineering)
  • Re: Hum but no motion
    ... smaller bench grinder which has a sharpening jig attached. ... The motor started ... dirty inboard startup switch ...
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  • Re: Hum but no motion
    ... If it happens again, spin grinder fast by hand and turn on, it will ... the switch. ... my smaller bench grinder which has a sharpening jig attached. ... Dirty start winding contacts. ...
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  • Re: HSS vs TCT
    ... only cost a few pounds grind them up and see how they work, ... Of course if you are sharpening end mills etc ... then a decent tool grinder is essential, for normal lathe tools I find ... an off-hand grinder and a couple of hours invested in practise sorts ...
    (uk.rec.models.engineering)
  • Re: Making Lathe Bits Without the "Right" Tools
    ... Consider putting the cutting tool in a bench vise as Jim suggested, or make a bracket/framework to hold the angle grinder so it can be securely mounted in a vise or attached to something stationary, like a bench. ... Trying to use a 4-1/2" angle grinder wheel on a 3000 RPM bench grinder won't work very well at all, but getting a larger diameter wheel intended for bigger angle grinders may produce satisfactory/better results, although you'll need to make an accurate and safe adapter to mount a larger wheel to the bench grinder arbor/shaft. ... There are some tool sellers that sell 8 piece pre-ground HSS cutting tool sets for about $40. ...
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