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
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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
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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?
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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?pageI520
Jacobe Hazzard wrote:

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Daniel H wrote:

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
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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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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.

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