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Re: Do you profile your cap irons?

Patrick Chase
David, you seem to be assuming that the cap iron can never extend below the sole of the plane.

I don't think that's really a constraint. It's bad news if the cap iron *corners* project below the sole (because then they can end up "cutting solo" if they extend beyond the iron on either side) but there's no such constraint on the center of a cambered cap iron.

For powerful evidence to the contrary look no further than the Kato/Kawai video. Their most effective configuration used 0.1 mm of setback and a 0.1 mm cut. The setback is measured along the back of the iron, so in that configuration the cap iron was about 0.03 mm below the surface of the wood.

In short, if you camber the cap iron then the center can safely extend below the sole. Whether that's *necessary* is a different question that I feel less well equipped to answer. I can buy an argument that positioning the leading edge of the cap iron in the plane of the sole should give adequate cap-iron effect such that there's no need to go deeper. The ratio of shaving thickness to cap iron setback is sqrt(2)/2 ~= 0.7 in that configuration for a 45 deg bed, which I think we all know to be pretty good. It's the geometric equivalent of taking a 2.8 mil shaving with 4 mils of setback.

Furthermore, with a straight cap iron positioned in the plane of the sole the depth:setback ratio is constant across the entire cut, and I can see how one might argue that this is optimal.

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Whelan planemaking book?
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Can't answer about the Whelan book
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Thanks (NM) *NM*
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Whelan planemaking book?
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Nice Article!
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Dimensioning: Question about roughing planes
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Do you profile your cap irons?
Re: Do you profile your cap irons?
Re: Do you profile your cap irons?
Re: Do you profile your cap irons?
Re: Do you profile your cap irons?
Re: Do you profile your cap irons?
Re: Do you profile your cap irons?
Re: Do you profile your cap irons?
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Re: Do you profile your cap irons?
Nicholson
Re: Do you profile your cap irons?
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Fun with math
Where did the ball go?
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Focussing on the key point
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Re: Do you profile your cap irons?
Re: Do you profile your cap irons?
No worries *NM*
Reference: Peter Nicholson, 'The Mechanic's Compa
Peter Nicholson plate XII, pages 91 to 93 *NM*
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Errors or suboptimal statements in books
Everybody makes mistakes
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Things that can be out of date, too
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Thanks Patrick *NM*
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