Homebrew PCBs

A green wheel would be tough to do it with, but it would work for 
making an engraving cutter.  Keep in mind, you have to dress the 
wheels prior to, and frequently during grinding.  

I have used diamond wheels on mills and on "tool grinders".  
Obviously the mill isn't the tool of choice, but in a pinch you 
gotta do what you gotta do!  Tool grinders have nice, exposed 
spindles so that you can manipulate the tool bit at various angles 
to the diamond wheel (usually a cup wheel).  I suppose you could 
mount one on a bench grinder if you have the correct size arbor or 
adapter.  You would also have to leave off the outer wheel cover so 
you have access.

During my first few years as a machinist, I used to have to hand 
grind form tools for use in CNC machines. These tools were either 
carbide or HSS.  The form tools where then used to mill slots on 
babbit bearings (thrust bearings).  These slots allowed the oil to 
flow up onto the face for lubrication.  The bad part of it was every 
bearing had a different profile for these oil grooves.  It seemed as 
though the designers followed no standards, just drew up what looked 
good at the moment.  So, I would have to grind up the tool by hand, 
making comparisons to radius gages etc.  The good part is that while 
the bearings were made to exacting standards and inspected by the 
vendor, they were never really picky about those oil groves - thank 
goodness.  

So, back to the topic at hand, I used the green wheels on the bench 
grinder to create these. It was much faster for me to do it free 
hand at the bench grinder than to use jigs and such with a tool 
grinder and diamond wheels.  So, you can do some very intricate 
stuff with green wheels, just don't try to do it fast ;-)

Chris




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> On Tue, 25 Jul 2006 22:28:31 +0200, lcdpublishing  
> <lcdpublishing@...> wrote:
> 
> > LOL!
> > I can just picture me standing in front of a grinder today (with 
my
> > bad eyesight) trying to hand grind a point on a .035" carbide 
drill
> > bit :-)  I can barely grind the .250" drill bits anymore :-(
> > The more I think about it though, I am going to pick up either a
> > soft-green wheel or a diamond wheel.  I plan on giving the 
isolation
> > milling a try when I get the little machine done (sometime during
> > the next century).  I suppose someone makes bits for isolation
> > milling but I have not seen any in the grab-bags of bits I have 
been
> > buying.
> > So, in the spirit of doing everything else, why not make an 
attempt
> > at grinding tiny bits to drive myself crazy ;-)
> > Chris
> 
> 
> You think the soft green wheel will do them? I think i got one 
with that  
> belt sander/grinder combo...
> But i would not expect the runout to be anywhere near acceptable 
to avoid  
> breaking them bits...
> 
> 
> What sort of grinder do the diamond wheels need?
> 
> ST
>