On Wed, 26 Dec 2007 02:05:42 GMT, "Harold and Susan Vordos"
wrote:
wrote in message
.. .
I've just bought a diamond wheel-dresser which is a steel rod with a
block of steel at the end with a 1.5" x 1/2" face with coarse diamonds
stuck to it.
Anyone know how the diamonds are attached?
They are usually set in a copper alloy of sorts.
And how rugged are these
things to having the diamonds knocked off?
Unless yours is one of the plated variety (it would likely be nickel colored
if so), you don't have to worry about knocking the diamond off, it's not
just glued on the surface. It is held captive by being poured in the
matrix.
Thanks, Harold, this thing is silver all over (looks plated).
Does this mean it is fragile? If so, how should I care for it over and
above what you recommend in general?
Can you just push it against a wheel at any angle? I mean with the
leading or trailing edge of the dresser hitting the wheel first? Or
must you be careful to get the centre of the dresser to hit the wheel
first?
It's your dressing tool (they're called a cluster diamond), so use it as you
wish, but if you want it to last, make sure only the diamond comes in
contact with the wheel. If you introduce it at a wonky angle, you may hit
the matrix instead of the diamonds, and that has the potential to screw up
the mounting such that you could lose diamonds on the periphery of the tool.
This has many 50 grit diamonds, maybe thousands. I doubt you could hit
matrix without being wasted by diamonds beforehand.
Should the dresser be held against the tool rest, or can you
just hold it freehand?
While you may be able to use it freehand, a rest helps control the cutting
action. It's also a little safer, If you slip freehand, you can end up
tangled with the wheel. You can believe me when I tell you that hitting a
running wheel with your hands can ruin a good day.
This I know, but don't ask me how
Are light "cuts" advisable? I've been a naughty
boy and used the wheel for aluminium. I have stood to one side, just
in case, however.
Don't horse it----but insure that it makes contact well enough to actually
do something to the wheel. Introduce it to the wheel, then work it
sideways, slowly feeding inwards until you have the surface of the wheel as
you like it. Keep it moving side to side to avoid creating grooves in the
wheel, which can actually ruin the dressing tool.
By horse it, I guess you mean push it in so hard it slows the wheel?
Also. I've just bought a new slower speed grinder (1425 rpm - 4-pole
on 50Hz) with a gray GP wheel and a white alumina wheel. Which would
be the best for touching up carbide-tipped lathe tools?
Neither one.
While I don't recommend them, aside from diamond or CBN, only a silicon
carbide wheel will perform with any degree of satisfaction on carbide.
Aluminum oxide (both of your wheels are aluminum oxide) is far too soft to
be effective.
Why is one white and one grey? The Al2O3 white one is meant for HSS
and apparently does a better job on that, so what is the grey one
meant to do? The white wheel has WA 12 L stencilled on it, and the
grey has A 60 M, I think (not too sure about the A as only half of it
got stencilled) Then there is the maker's brand, and 40 m/s.
If you want really good results, buy a diamond wheel, and run it wet.
Can you do this on a 1425rpm dry grinder? What would an 8" diamond
wheel likely cost? Would you just let water drip slowly from a bottle
on a shelf via a plastic tube?
Otherwise, a green silicon carbide wheel will work. The dust is
hazardous------causes silicosis-----and the finish such a wheel leaves
leaves a great deal to be desired. Silicon carbide (green wheel) isn't all
that much harder than carbide, so it tends to club it off instead of cut it
cleanly the way a diamond wheel does.
Way back, I just used the grey wheel that was in the grinder without a
thought. jack
And it did a poor job of almost everything, didn't it?
Seemed OK to me, but then, I'm just an inexperienced amateur.
Maybe it had a SiC wheel in it, coz it seemed to put a nice edge on
out carbide tools. This was just a small lathe in a university
laboratory workshop.No critical work was ever done on it.
Thanks for your help, Harold, jack