Preparing the chip breaker on LN#4

[Tony Wilkins]

As part of all the information on the benefits of a closely set chip breaker I noticed that honing it was part of the equation. I'm set to work on the one from my Lie-Nielsen #4 but want to make sure I have it right before taking it to stone. The side that rests against the blade should be flat correct? Don't think that should take long on an LN cap iron. The other side should be hone to 45* or greater with 50* or higher optimum?

[Patrick Chase]

As part of all the information on the benefits of a closely set chip breaker I noticed that honing it was part of the equation. I'm set to work on the one from my Lie-Nielsen #4 but want to make sure I have it right before taking it to stone. The side that rests against the blade should be flat correct? Don't think that should take long on an LN cap iron. The other side should be hone to 45* or greater with 50* or higher optimum?

The side that rests against the blade should be flat across the blade, but should have a bit of undercut along the blade's long axis. An LN breaker should already be near-perfect in both respects, such that you just need to hone the leading edge a bit.

What you ultimately want is a continuous line of contact between the back of the blade and the leading edge of the cap iron. Tightening the cap iron will cause it to "flatten out" against the blade, so if it isn't undercut to begin with then doing so will cause the leading edge of the cap iron to lift away from the blade, which is very bad.

[Pat Barry]

The side that rests against the blade should be flat across the blade, but should have a bit of undercut along the blade's long axis. An LN breaker should already be near-perfect in both respects, such that you just need to hone the leading edge a bit.

What you ultimately want is a continuous line of contact between the back of the blade and the leading edge of the cap iron. Tightening the cap iron will cause it to "flatten out" against the blade, so if it isn't undercut to begin with then doing so will cause the leading edge of the cap iron to lift away from the blade, which is very bad.

+1 --- Keep the leading (contact edge) flush to the blade and close to the edge -down by the river (= for Prashun!)

[Tony Wilkins]

Great! Thanks for the quick replies.

Is my understanding of beveling the other side of the cap iron to greater than 45 degrees correct? If so my plan is to start at 45 and deepen it as I hone it periodically in future.

[Pat Barry]

Great! Thanks for the quick replies.

Is my understanding of beveling the other side of the cap iron to greater than 45 degrees correct? If so my plan is to start at 45 and deepen it as I hone it periodically in future.

A 45 degree bed angle with another 45 on the chip breaker might be a tad too much, athough I don't recall the Kato video's on the topic, it just seems a bit steep.

[Derek Cohen]

I added a 50 degree bevel to the leading edge. Be aware that the LN chipbreaker does not have a lot of meat in the area. That is, the ledge is quite narrow, and a bevel will further reduce its width. The bevel does not need to be more than a 1/16".

I have also played with rounded vs flat leading edges. I cannot notice a difference. Leave it flat.

Regards from Perth

Derek

[Tony Wilkins]

I added a 50 degree bevel to the leading edge. Be aware that the LN chipbreaker does not have a lot of meat in the area. That is, the ledge is quite narrow, and a bevel will further reduce its width. The bevel does not need to be more than a 1/16".

I have also played with rounded vs flat leading edges. I cannot notice a difference. Leave it flat.

Regards from Perth

Derek

Thanks Derek. I was just on your site reading about this (in the veritas custom plane articles)

[Robert Engel]

You shouldn't have to touch a LN. Personally I would be very hesitant to mess with it.

I've never seen the need to do this except a cheap plane or damage cap iron.

[Brian Holcombe]

I bevel mine pretty steeply, maybe 75 degrees~

Robert, all part of the setup process, nothing wrong with moving away from the factory set. Cap irons wear and must be maintained in addition to initial setup.

Ive also replaced the blades on mine, so they are no virgins.

[Prashun Patel]

close to the edge -down by the river (= for Prashun!)

YES, Nice!

Tony, beware of messing with it out of the box. I would personally use it without fiddling with the breaker. If you find that shavings jam there or it stops cutting, despite a well-sharpened blade, then perhaps you can look there.

[Derek Cohen]

You shouldn't have to touch a LN. Personally I would be very hesitant to mess with it.

I've never seen the need to do this except a cheap plane or damage cap iron.

Robert, the factor leading edge on both the LN and the Veritas chipbreakers is 30 degrees. This is too low for the chipbreaker to redirect shavings appropriately. It needs to be around 50 degrees. Honing a secondary bevel is the easiest way to do this.

Regards from Perth

Derek

[Pat Barry]

A 45 degree bed angle with another 45 on the chip breaker might be a tad too much, athough I don't recall the Kato video's on the topic, it just seems a bit steep.

Just watched the video again, they concluded that a much steeper angle (80 deg) was most effective at reducing tearout
.http://giantcypress.net/post/2315954...deo-created-by
What is the chipbreaker angle as delivered by LN?

[Keegan Shields]

Sorry to revive this thread. I’m playing around with a secondary bevel on the chip breaker of my LN 4 1/2. I tried 45 deg, since that’s what my guide goes up to, and it seemed to help a bit in some knotty white oak I’m using as a test.

Based on that video from Japan, it looks like their recommendation is an 80 deg bevel set back 0.3mm or between 1/64th and 1/128th when taking a .1mm shaving (4 thou)

Does that sound right?

[Jim Koepke]

Sorry to revive this thread. I’m playing around with a secondary bevel on the chip breaker of my LN 4 1/2. I tried 45 deg, since that’s what my guide goes up to, and it seemed to help a bit in some knotty white oak I’m using as a test.

Based on that video from Japan, it looks like their recommendation is an 80 deg bevel set back 0.3mm or between 1/64th and 1/128th when taking a .1mm shaving (4 thou)

Does that sound right?

You may get lots of opinions on whether or not this sounds right. The real test of it being right or not is how the shaving is exiting. If the shaving is jamming or crinkling like the bellows of an accordion, then you are set too close.

With a shaving at 0.004" the chip breaker doesn't have to be real close. That is a fairly thick shaving for smoothing. In the past some have suggested setting the chip breaker back just a half hair further than the thickness of the shaving to be taken.

jtk

[Mike Brady]

Leave it alone. Who so you think would most likely be the expert on this subject? If you have a question the LN folks could answer it.