----- Original Message -----
From: Bill Taggart 
Sent: Sunday, 25 April 1999 09:30
Subject: Re: Iron thicknesses was Re: FWW Smoothing Plane Article


> >instant chatter.  Remedy is to change the bevel angle until its base
> >rests in the frog instead of the sole.
>
> Can we explore this a wee bit further?
>
>
> Do I need to regrind the bevel at a bit sharper angle? They've got the bevel
> supplied by Mr. Hock. What angle should I shoot for? Don't want to start any
> holy wars here, just my usual quest for knowledge and I'm not embarrassed to
> ask stupid questions - don't know of any other way to learn...
>

I dunno if I'm the right person to reply but since I started it, here
goes what worked for me:

Grind a hollow ground angle.  Now, the trick is this.  Most hollow ground
instructions say that you leave two flat lips on the bevel, one near the edge
and the other near the heel of the bevel.  This is difficult to achieve IME
with a normal diameter grinding wheel.  But it can be done.  What I do
for these thick blades is to hollow grind all the way up to the heel of the
bevel
and leave the same flat portion near the edge. The end effect is that the heel
of the bevel is pushed back up the iron.  It now clears the lip on the sole in
a
frog that has been pushed back.  The exact angle to do this varies with the
iron and plane you're using.  Start easy then fit the whole lot together before
sharpening the edge, go back to the grinder and repeat until fine.  You may
have to "push" the heel of the bevel further up than it was before. No problem,
just change the angle to achieve this.  Then put the final edge on the narrow
flat with whatever angle you fancy.

Err on the side of under-grinding.  The net effect is one of reducing the
thickness of the iron near the edge.  The cap iron is more than enough
to compensate for this and I have yet to experience any serious chatter
this way. The rest of the thick iron also negates chatter.
YMMV, hence the warning.

To set the grinding angle accurately switch off the grinder, land the iron on
the toolrest (you need a big wide one for this, forget the little fancy jokes
they put nowadays on commercial grinders) then touch the iron to the wheel
with the toolrest loose and jiggle things around looking at it sideways.
Once the angle is what you think it should be, tighten up.  Remove the iron,
switch on and do a light pass to see if everything is okdokey. If not, switch
off and repeat until you're happy.  Grind away gently to not overheat.
It takes a while to do this with no overheating but it only needs to be done
once in a blue moon so take a cuppa and relax. H-C irons like Hock's are
easier to grind this way than the newer HSS or A-n whatever steel, so be
gentle.

HTH

One word of caution here.  This is only necessary in the old Stanley tools.
Their mouths were too tight for a thick iron and that's why the problem
is there.  On newer ones, the mouths are much wider so you may find
that none of this is needed when fitting a thicker iron.

As usual YMMV, IMHO, no animals were hurt in these experiments, etc.

Cheers
Nuno Souto
nsouto@n...
http://www.acay.com.au/~nsouto/welcome.htm