JH

"Jacobe Hazzard"

07/11/2004 10:35 PM

MORE questions about block planes.

I'm a bit confused about an article I've just read:

http://www.woodmagazine.com/wood/story.jhtml?storyid=/templatedata/wood/story/data/blockplane.xml

or

http://tinyurl.com/54lry

Specifically I'm looking at the diagram titled 'Cutting Edges Comparison'.
I had not known that block plane irons are used bevel up. If that's the
case, then doesn't the cutting edge in a block plane present angles to the
wood that are identical to a bevel-down plane iron with a higher bedding
angle? The diagram seems to confirm this.

How then does the block plane behave any diferently than a bench plane,
other than the smaller size?

Thanks,

Adam


This topic has 6 replies

Gg

"George"

in reply to "Jacobe Hazzard" on 07/11/2004 10:35 PM

08/11/2004 6:26 AM

There's more to cutting than the edge. The gap through which the shaving
must pass, the extent to which the shaving is curled, as well as the force
behind the cut all play a role.

The major difference between a block and a bench plane has less to do with
the angle of the cut than the way the shaving is handled and the way you
handle (pun intended) the plane.


"Jacobe Hazzard" <[email protected]> wrote in message
news:[email protected]...
> Bob wrote:
>
> So then the only difference is the size?
>
> Can a low-angle block plane use a plane iron with a larger bevel angle to
> simulate a normal blade angle? Are there complications with the 12 degree
> clearance angle on the flat side that would make it behave differently
> from a standard block plane?
>
>

DH

Daniel H

in reply to "Jacobe Hazzard" on 07/11/2004 10:35 PM

07/11/2004 11:48 PM

Jacobe,

Please reread my replies to your initial plane questions:
http://groups.google.com/groups?threadm=uqydnR0VldtIB-PcRVn-jQ%40rogers.com

I suggested buying another blade and sharpening it at a higher bevel
angle so that, when mounted in a low-(bed)-angle block plane, you get a
*total* cutting angle in excess of 45-degrees, the cutting angle of
planes used to smooth difficult-to-work grain. The Lee Valley product
page URL I quoted was for EXACTLY such a product - high-angle blades to
their low-angle smooth and jack planes. Here is the page again:
http://www.leevalley.com/shopping/Instructions.asp?page=49520

Jacobe Hazzard wrote:
> Can a low-angle block plane use a plane iron with a larger bevel angle to
> simulate a normal blade angle? Are there complications with the 12 degree
> clearance angle on the flat side that would make it behave differently
> from a standard block plane?

JH

"Jacobe Hazzard"

in reply to "Jacobe Hazzard" on 07/11/2004 10:35 PM

08/11/2004 1:00 AM

Daniel H wrote:
> Jacobe,
>
> Please reread my replies to your initial plane questions:
>
http://groups.google.com/groups?threadm=uqydnR0VldtIB-PcRVn-jQ%40rogers.com
>
> I suggested buying another blade and sharpening it at a higher bevel
> angle so that, when mounted in a low-(bed)-angle block plane, you get
> a *total* cutting angle in excess of 45-degrees, the cutting angle of
> planes used to smooth difficult-to-work grain. The Lee Valley product
> page URL I quoted was for EXACTLY such a product - high-angle blades
> to their low-angle smooth and jack planes. Here is the page again:
> http://www.leevalley.com/shopping/Instructions.asp?page=49520


You're absolutely right, when I read your post I had a vague idea about
the bevel angle determining the cutting angle, but I somehow missed the
bit about block planes being bevel-up.

There's still one point I'm not clear on, hopefully you haven't already
adressed it :-) If I compare a regular block plane with a 45 degree total
cutting angle and a low-angle block plane with a high-angle blade that
also gives a total cutting angle of 45 degrees, there's one difference I
can see. The low-angle plane will have a smaller clearance angle on the
flat (under)side of the blade than will the regular plane. I would suppose
that since this face of the blade isn't exerting a lot of force on the
wood anywhere but at the very edge, this angle is relatively unimportant
and the two planes described above would function similarly. Is that the
case?

Thanks for your patience.

Adam

Bb

"Bob"

in reply to "Jacobe Hazzard" on 07/11/2004 10:35 PM

08/11/2004 3:46 AM


"Jacobe Hazzard" <[email protected]> wrote in message
news:[email protected]...

> How then does the block plane behave any diferently than a bench plane,
> other than the smaller size?

Your answer is right there in the article just above the diagrams you
mentioned.

"The block plane owes its handy size in part to the shallow angle between
the blade--or iron--and the sole. "

Bob

JH

"Jacobe Hazzard"

in reply to "Jacobe Hazzard" on 07/11/2004 10:35 PM

07/11/2004 10:58 PM

Bob wrote:
> Your answer is right there in the article just above the diagrams you
> mentioned.
>
> "The block plane owes its handy size in part to the shallow angle
> between the blade--or iron--and the sole. "
>
> Bob

So then the only difference is the size?

Can a low-angle block plane use a plane iron with a larger bevel angle to
simulate a normal blade angle? Are there complications with the 12 degree
clearance angle on the flat side that would make it behave differently
from a standard block plane?

sS

[email protected] (Sbtypesetter)

in reply to "Jacobe Hazzard" on 07/11/2004 10:58 PM

08/11/2004 6:35 AM

Yes,. 12 degrees is about the minimum for clearance angles. The wood can begin
to fuzz behind the blade if you go any
lower. Also, To maintain a Type ll cut,
the blade needs to be sharpened within a
specific range of angles. Just read about
it tonight, but now it slips me. The
minimum a steel blade can be successfully
sharpened is about 25 degrees.
The above was from Brian Burns booklet;
Double Bevel Sharpening.

-Rick


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