Couple of weeks back, Thomas McCluskey inquired about the proper skew angle
of cutters for the Stanley 46 plane, to which Patrick Leach replied:

>> 25 degrees +/- an angstrom or two.

There are several angles involved on a 46, and I wasn't exactly sure which
one Thomas was asking about, so I decided to pull out a couple of 46's and my
trusty Starrett adjustable protractor to see for myself. Having made cutters
for 46's, I'd dont this before, but I couldn't find my notes.

Here's what I measure:

The skew of the blade: assuming this means the angle at which the blade sits
in the plane referenced to the side of the plane which is parallel to the
direction the plane moves in use, this angle is 60 degrees, or 30 degrees
deviation from the 90 degrees at which most plane blades rest referenced to
the plane side. 

The pitch of the blade, or the angle at which it sits in the plane referenced
to horizontal, is 61 degrees (as opposed to 45 degrees which is common for
bench planes and molding planes).

Most plane blades have a cutting edge which is 90 degrees to the edges of the
blade. On a 46, the cutter edge angle is 71 degrees/109 degrees (depending
on which edge you measure from).

The long edge of the blade is beveled to 110 degrees from the cutting face of
the blade to provide the necessary relief.

The short edge of the blade is beveled to 70 degrees from the cutting face to
provide support for the cutting edge but with relief also. Note that if the
blade were mounted in the plane square instead of skewed, the back of this
edge would actually protrude further to the left than the cutting edge.

I haven't been able to figure out which angle Patrick measured at 25 degrees.
There is very slight deviation between my c. 1880's 46 and my c. 1920 model.

I'm sure my terminology and descriptions are confusing, but I look forward to
further discussion.

Don Boyer

On Sun, 31 Aug 1997 16:16:19 -0400 (EDT) Dnbyr@a... writes:
>Couple of weeks back, Thomas McCluskey inquired about the proper skew 
>angle
>of cutters for the Stanley 46 plane, to which Patrick Leach replied:
>
>>>  25 degrees +/- an angstrom or two.
>
>snip all the measuring stuff.

Thanks for the response

Chock it up to newbie lack of vocabulary. 

 I reasoned that the angle/angles that the cutter clamps into the plane
is fixed. ( I can't change it)   The only angles I control as someone who
wants to sharpen his blades accurately, is the bevel angle (the primary
angle of the cutting edge in relation to the flat part of the blade)  and
the skew angle (the angle  of the the cutting edge in relation to the
sides.)  On a typical plane blade the "standard" bevel is 25 degrees. 
The "standard" skew  is 90 degrees ( or maybe 0 degrees)

(BTW I am trying to indicate my understanding whether correct or
incorrect by use of parentheses)

Based on the input from the group, the skew on the #46 cutter is 68 to 71
degrees.

BTW what was the variance on your 1880s vs. 1920s?.  The reason I ask is
my plane is from the 20s and the cutters wers purchased separately and
are older.

Anyone have good definitions for the various blade angles we've
discussed? (Newbie has inquiring mind and needs to know to prevent future
faux pas.)

At 10:45 PM 8/31/97 EDT, Thomas E. McCluskey wrote:
>
>On Sun, 31 Aug 1997 16:16:19 -0400 (EDT) Dnbyr@a... writes:
>>Couple of weeks back, Thomas McCluskey inquired about the proper skew 
>>angle
>>of cutters for the Stanley 46 plane, to which Patrick Leach replied:
>>
>>>>  25 degrees +/- an angstrom or two.
>>
>>snip all the measuring stuff.
>
>Thanks for the response
>
>Chock it up to newbie lack of vocabulary. 
>
> I reasoned that the angle/angles that the cutter clamps into the plane
>is fixed. ( I can't change it)   The only angles I control as someone who
>wants to sharpen his blades accurately, is the bevel angle (the primary
>angle of the cutting edge in relation to the flat part of the blade)  and
>the skew angle (the angle  of the the cutting edge in relation to the
>sides.)  On a typical plane blade the "standard" bevel is 25 degrees. 
>The "standard" skew  is 90 degrees ( or maybe 0 degrees)
>
>(BTW I am trying to indicate my understanding whether correct or
>incorrect by use of parentheses)
>
>Based on the input from the group, the skew on the #46 cutter is 68 to 71
>degrees.
>
>BTW what was the variance on your 1880s vs. 1920s?.  The reason I ask is
>my plane is from the 20s and the cutters wers purchased separately and
>are older.

Tom,

I made access and unpacked the box containing my No.46 this weekend  and took a measurement. Same as previously reported, I
think by Ernie, at near 68.5 degrees. This is from original boxed blades
that came with an early Type 5 (1884-85) according to the Roger Smith study
in the latest Walter. Hope this helps more than my previously flippant
reply which suggested measuring, etc.

David

Or of course you can all wait until Ron and I put the drawings for all the
No.46 cutters up on his site :).

Regards,

--------------------------------------------------
Brent Parkin

Toronto, Ontario
Canada eh!

** Reply to note from tmcclus@j... Sun, 31 Aug 1997 22:45:29 EDT

GGs,

A skewed blade has three angles of interest. The skew angle, the beddinga
angle and the bevel angle.

My definitions of these angles are as follows:

Skew angle: The angle between 90 deg to the side of the plane and the back of
the mouth. Skew is the angle the blade is moved from normal, which is 90 deg.
This angle is measured on the sole of the plane.

Bedding angle: This is the angle between the sole of the plane and the iron.
Typically 45 deg.

Bevel angle: The angle of the bevel measured at 90 deg to the edge.

The skew angle is NOT the same as the skew on the edge of the blade due to the
effect of the bedding angle.

If the edge of the blade is parallel to the back of the mouth you can use the
blade as a reference and just measure the angle from the blade (record it
somewhere safe). Otherwise it can be developed geometrically from the skew
and bedding angles. Or just believe us.

In practice the blade can be fiddled with slightly to make small changes in
the skew angle when it is mounted in the plane.

Ernie
I'm not a collector, really. I'm just a user without enough time.
(used by permission)

In a message dated 97-09-01 22:27:13 EDT, Ernie writes:

<< A skewed blade has three angles of interest. The skew angle, the beddinga
angle and the bevel angle.
>>

To which I must add, the relief angle of the right edge and the anti-relief
angle of the left edge, which as I've already noted, are different on 46
cutters. I defined the relief angle as that angle defined by the flat
cutting surface of the blade (the surface facing the front of the plane in
use as opposed to the beveled surface) and either side edge of the blade, as
measured 90 degrees to the edge. As I noted earlier, without the proper
relief angle, the trailing edge of the blade would drag in the groove cut by
the plane, or if too much relief were provided, the cutting edge might have
insufficient support at that edge.

Ernie seems to have a great handle on wording these things, so perhaps he can
take a stab at clarifying what I've just tried to say. 

Thanks for the great input, Ernie.

Don

On Mon, 1 Sep 1997 08:11:35 -0400 (EDT) Brent Parkin
parkinb@w... writes:
>Or of course you can all wait until Ron and I put the drawings for all 
>the
>No.46 cutters up on his site :).
>
>Regards,
>
>--------------------------------------------------
>Brent Parkin
>
>Toronto, Ontario
>Canada eh!
>
Brent

Still waiting. Give me a post when you are up and I'll go get on the
'Net at the library. I'm cheap. I'd rather spend my money on tools than
on computers.

Tom