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Hi all!
A light, lounge topic for those who feel inclined: I wonder what are your thoughts on corrugated planes? i´ve heard both: "it helps on heavier planes, because you get less contact with the wood and, consequently, less friction and smoother action" and "it´s just wishful thinking, the practical effect is just nill".

thanks for reading,
miguel.

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member of the guild of professional dilettantes

I have both types in a Bedrock No. 605 -can't tell any difference in real world performance.

Kevin Looker

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I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

They are easier to flatten.

Corrugated planes suck when it comes to shooting thin plates.

I could never feel any difference when surfacing large planks. A scribble of wax dwarfs any sight difference that might exist.

For vintage planes, the Cs seem to be easier to find and cheaper.

-jd

have a number 6 corrugated with old school fence , forget it. Only useful for stock over 3/4in and over 5 in wide. My lie -nelson large shoulder plane with shooting board is much more accurate for shooting plates.

Friction is independent of surface area. The size of the friction force depends on how are hard the plane against the wood surface, and the interaction between the surfaces; wood and metal, (this is what changes when you put some wax on the plane surface). So having groves in the plane won't reduces the friction.

Cheers,

Stefan

Well, from an engineering standpoint, friction force is a direct function of surface area. So it can make a difference.

I understood that the CS planes were for working resinous woods, where the stickiness of the resin over a larger surface area may make a difference.
As I remember, friction is a function of weight, or force between the surfaces involved, not a function of surface area (according to my physics teacher - It was an exam question at elemetary level)

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

thanks for the replies. i got a bit confused with the friction part, so i got back to my elementary physics (it´s been a while), and indeed friction is independent of surface area and, in most situations of concern to this, a function of the weight of the plane... counter-intuitive, but it´s what´s in the book. i also did not know about that thing about resinous woods and CS, but i wouldn´t want to plane down a very resinous wood anyway. spruce is as resinous as i care to handle!

anyway, thanks again!
miguel.

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member of the guild of professional dilettantes

If anything, the cut in the plane sole would increase friction, same way tracks are cut into shoes and tires in order to increase traction...

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

OK, now this is getting complicated... yes, i´d believe that tires have the grooves for channelling water.
maybe corrugations won´t help with friction, but i´ll have an hard time believing they will actually make it worse (but i´ve happily forgot all high school physics ). the rationale would be, i suppose, that in shoe soles the material is elastic, so it gets compressed when you step and when it decompresses the holes within it become larger, pressure drops and suction happens. The steel of the plane sole won´t behave like that, right?

cheers,
miguel.

_________________
member of the guild of professional dilettantes

Patrick Leach says at http://www.supertool.com/stanleybg/stan1.htm

"The "C" designation means that the sole has a series of parallel grooves machined into it. There is no "C" cast into this plane, nor any other of the corrugated bench planes.

The corrugations are provided to overcome the 'friction' that results between the wood and the sole as the wood becomes true; a small vacuum forms between the two surfaces. Whether this 'friction' becomes a bother to the craftsman depends upon the species of wood being planed and the overall strength or endurance of the dude pushing the plane. I've never really been bothered by the 'friction', but it appears that many others have, judging by the number of corrugated planes out there and the length of time that they were offered. Some also claim that the corrugations are useful on resinous woods - maybe you will, too.

Prior to the introduction of corrugations, guys would use wax or oil on the plane's sole. This was normally used on the longer planes, where the amount of 'friction' is certainly greater than that formed on the shorter planes."

as mentioned, the groves in found on tyres and shoes are for clearing water. Hence why racing cars use slick tyres with no groves, cutting groves into the tyres add about 3 seconds to an f1 car's lap time!


physically, friction occurs because of the electro static/dynamic interaction of the two surfaces, therefore the larger the contact patch, the larger the available friction force, I suppose.

The standard physics equation most of us know is generally given in the form F=cR where F is the friction force, c is the coefficient of friction (normally a mew...) and R is the reaction force. The coefficient of friction must be calculated for every situation, therefore absorbing the surface area dependancy of the equation. I'm not quite sure what else the expression would be dependant on to balance the dimensions however... any engineers wish to clarify?

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