On Sat, 31 Jan 2004 22:24:38 -0800, "Harold & Susan Vordos"
wrote:
"Errol Groff" wrote in message
.. .
snip---
First, I ALWAYS use the toolrest. I have it set to the angle that I
have found works for the type of jobs that we do and God help the kid
who changes the angle setting.
I fully agree in your particular setting. When one is in a learning curve,
and the work at hand is relatively predictable, so leaving the rest at a
desired angle is certainly not unreasonable. Where that begins to get in
the way is when one is far more familiar with tool grinding and desires to
grind features not generally taught in class. The use of a tool rest,
perhaps when learning, keeps you out of trouble regards safety, and helps
establish proper relief angles, but is a definite liability when you have
gained enough experience to grind tools well. That was a hard lesson for
me to learn. It came only when I was hired in a job shop where time was
ultra critical.
I had been working as a machinist for over 8 years when I was exposed to the
no tool rest concept. Very uncomfortable at first, it was. In the end,
though, I can honestly say it is the best thing I ever learned about
sharpening tool bits, and I never struggled with them from day one. It just
made an easy job all the easier for me.
I don't see that it matters what face of the tool is done first or
last, having said that I usually do the side, top and end in that
order. Some years back I got sick and tired of grinding from solid
and made a simple jig to hold the tools for top and side grinding on a
surface grinder. The ends I always do by hand on the pedastal
grinder. Re-sharpenings are done on the pedastal grinder.
I'm with you. The only rule I have is that I generally sharpen the front
face last, but only because it guarantees the width of many of the tools I
grind. I'm comfortable with grinding parting and grooving tools within a
thou, and the last bit is best done by removing a tiny amount from the face.
It also allows you to achieve a right angle with the sides, leaving you a
bit more wander room as you rough out the tool. YMMV.
In place of a surface grinder, when I finally get my shop up and running
again, I plan to use parting wheels to rough out toolbits. That only because
I picked up an old cutter grinder, though. Grinding parting and grooving
tools is slow business, but they can be roughed out in less than a couple
minutes with a parting wheel by removing pieces instead of grinding
everything away. All that is left is to grind proper relief and rake on
the tool, saving at least 80% of the grinding time. That, for me, is and
always will be a hand process, which is far easier than making constant
changes on a cutter grinder for all the different grinds. You have the
added benefit of being able to tailor the cut to the occasion. A holding
fixture on a surface grinder may or may not offer that option. Hopefully
you've designed it into yours..
Grinding parting and grooving tools ??? What is that? Thin disks?
What size of HSS are you using? I should just get my SG going and not
worry about it. Good thread. BTW, how do you know diamond dressed
wheels are "dull" and have to be fixed? I've stood in front of huge
grinding wheels for many hours. I need to work on my very cheap
grinder present , but figured if I was going to get it from one it
would have been long ago. I use to think of such things when starting
them up in the morning and wondering if some idiot hit it with
anything.
) Put a steel plate over the top so it won't knock you
out (head injury) , you can always bleed slowly , maybe. The biggest I
worked with was "about" 3.5' Dia. X 3". I was trained in three weeks
from completely broke and asking gas station patrons if they wanted to
buy this redwood waterbed that I built out of 3.5" X 13" laminated
beams. The guy was curious and asked me my background and told him
that I understood linear and rotational geometry and he was like do
you want my job I'll train you ...? I just bought machines and
figured it out may years later about cutting instead of grinding.
I have no real guards or rests , should! I'd love to have someone
show me something I don't know or could "see".
I get lost in printed descriptions. I just tense up and do it with a
very and hopefully non debated form 3 dimensionally in my mind and
do it. Like grinding the top ? If you put in a chip breaker then you
really have to grind a lot for the next when it wears out. Don't ask
me. The others know more.
If anyone is interested I will draw up the grinding jig and post it to
the dropbox.
I'd love to see it, Errol. Please let us know when it's there.
If you are holding the tool close ehough to the business end to
control the grind you wil know when the heat is building and cool the
tool long before it gets hot enough to bother the steel.
Yep! And if you happen to get it a bit too hot, place it against another
flat piece of steel and allow some of the heat to dissipate before quenching
it. That keeps the tool from fracturing.
As others have said the main key is practice, practice, practice.
Just my .02 on the subject.
Worth much more, Errol!
Harold