New planing behaviour knowledge - microscopes etc

[bugbear]

http://www.woodcentral.com/woodworking/ ... lade-wear/

http://planetuning.infillplane.com/html ... study.html

BugBear

 

[ac445ab]

This is a very interesting discussion
My question is about the chipbreaker: Is it really effective in breaking shavings and avoiding tearout?
From a Japanese study and experiences showed in links Bugbear indicated, seems the chipbreaker is effective only if its position is very close to cutting edge (0.1-0.2 mm). Moreover the angle the chipbreaker forms with the blade is also important to improve the results. Steeper angles seem better. Our experience?
If these are parameters, how is possible to exactly setting the chipbreaker so close to cutting edge? I'll need a microscope? :mrgreen:

 

[David C]

Yes it is really effective in preventing tearout.

I did one conclusive experiment in my workshop a couple of days ago.

The setting is quite difficult but not impossible. I find this research most exciting and a little galling, as the advice I have given over the last 35 years or so could have been better. i.e. Close is not good enough, ultra close works like magic.

Best wishes,
David Charlesworth

 

[Philly]

I wonder if a higher pitched plane works just as well? Without the worry of setting a back iron exceedingly close?
Just a thought,
Philly

 

[David C]

Philly,

As you know, I am a great fan of high pitches and effective pitches.

It has been suggested on the American forums that the close set chipbreaker at standard pitch produces a brighter surface than steep effective pitches. I have yet to try this experiment. However it seems that we have another weapon for impossible grain.

best wishes
David

 

[ac445ab]

It has been suggested on the American forums that the close set chipbreaker at standard pitch produces a brighter surface than steep effective pitches. I have yet to try this experiment. However it seems that we have another weapon for impossible grain.

best wishes
David

Moreover a standard pitch is easier to push, mainly for larger blades.


Ciao
Giuliano

 

[CHJ]

Philly,

As you know, I am a great fan of high pitches and effective pitches.

It has been suggested on the American forums that the close set chipbreaker at standard pitch produces a brighter surface than steep effective pitches. I have yet to try this experiment. However it seems that we have another weapon for impossible grain.

best wishes
David

Thinking about the geometry, are you not just simulating the burr edge on a good scraper blade ?

 

[Jacob]

.......
Thinking about the geometry, are you not just simulating the burr edge on a good scraper blade ?

That's what I thought too.
But in the real world getting a cap iron to within less than 1mm is not practical without very carefully machined components and very precise straight-edge sharpening i.e. not planing as we know it.
Pleased to see that they correctly call the flat side the "face" - well done chaps!
What I thought was interesting was the amount of wear on both faces of the blade - which you'd expect anyway but it's difficult to see. This is where stropping (polishing) the face and bevel, has such a big effect on performance: friction is reduced so cutting gets easier, and it follows that wear is also reduced, which we all know happens in practice.
Pity they didn't incorporate this in their study - and Steve Elliot has missed this essential detail.

Title of thread - "New planing behaviour knowledge ". Really? I see nothing radically new.

 

[Corneel]

In theory you are right Jacob, but practically it proves not to be a problem at all. Nowadays I sharpen my irons freehand and the smoothers are straight enough. You use the light reflected from the face to determine how far you are. No need to use callipers, but meassuring once gives you an idea how much 0.2mm looks like. What I do is install the capiron on the blade, the screw tightened until the capiron is pressed flat, but not fully tight. Then I push the capiron forward, keeping the edge in the light. You can see very well how the silvery line gets smaller and smaller. Finally tighten the screw.

Of course it helps to keep your stones flat while sharpening.

 

[Jacob]

In theory you are right Jacob, but practically it proves not to be a problem at all. Nowadays I sharpen my irons freehand and the smoothers are straight enough. You use the light reflected from the face to determine how far you are. No need to use callipers, but meassuring once gives you an idea how much 0.2mm looks like. What I do is install the capiron on the blade, the screw tightened until the capiron is pressed flat, but not fully tight. Then I push the capiron forward, keeping the edge in the light. You can see very well how the silvery line gets smaller and smaller. Finally tighten the screw..........

Yes I could do that, except non of my plane edges are that precise, they all have varying degrees of camber.

 

[bugbear]

This is where stropping (polishing) the face and bevel, has such a big effect on performance: friction is reduced so cutting gets easier, and it follows that wear is also reduced, which we all know happens in practice.

Yes - this was pointed out by Jeff Gorman, long ago - highly polished (and hence sharp) edges are less prone to wear and chipping. Welcome to our world.

BugBear

 

[Corneel]

Yes I could do that, except non of my plane edges are that precise, they all have varying degrees of camber.

You only need one precisionsmoother. You could put some effort in keeping that one straight. Maybe even lift the corners of the cap iron a bit.

What is your strategy to prevent or clean up tearout?

 

[Jacob]

Yes I could do that, except non of my plane edges are that precise, they all have varying degrees of camber.

You only need one precisionsmoother.

Yes I've got just one LV la bu smoother

You could put some effort in keeping that one straight.

I prefer a camber

......
What is your strategy to prevent or clean up tearout?

If all else fails I use the LV plane. Then it's the ROS!

 

[Jacob]

...- highly polished (and hence sharp) edges are less prone to wear and chipping. .....
BugBear

Chipping? I doubt it.
Stropping or polishing a narrow area behind the edge (2 to 5mm?) is not the same as polishing the whole face, or large areas of the face, as advocated by the polishing fraternity, for no apparent reason.

 

[bugbear]

...- highly polished (and hence sharp) edges are less prone to wear and chipping. .....
BugBear

Chipping? I doubt it.
Stropping or polishing a narrow area behind the edge (2 to 5mm?) is not the same as polishing the whole face, or large areas of the face, as advocated by the polishing fraternity, for no apparent reason.

yawn.

BugBear

 

[Jacob]

...- highly polished (and hence sharp) edges .....
BugBear

Oh and 'highly polished' (face and bevel) does not necessarily mean 'sharp', and vice versa.

 

[David C]

Chas,
Yes, very close to scraper geometry.

Jacob says;
"not planing as we know it"
"I see nothing radically new"
"Setting a capiron less than 1 mm is not practical"

For someone who has clearly not tried the technique, he has a lot to say about it !

David Charlesworth

 

[Jacob]

Chas,
Yes, very close to scraper geometry.

Jacob says;
"not planing as we know it"
"I see nothing radically new"
"Setting a capiron less than 1 mm is not practical"

For someone who has clearly not tried the technique, he has a lot to say about it !

David Charlesworth

I haven't tried homeopathy, cannibalism, line dancing and zoophilia. Have you?

 

[Racers]

Hi,

You must remember there is only Jacobs way and the wrong way. :wink:



Pete

 

[Jacob]

Yeah sorry; I know "thinking for yourself" upsets people, especially our resident prima-donnas, who get quite tetchy! :lol: :lol: