Cap Iron Deflection Angle.

[ED65]

...on the reasonable assumption that a shaving, once broken by the cap iron, will tend to continue on at the 'deflection' angle until it hits the wear...

I refer you back to the first page Nick, that is very much not the case. It's a shame it isn't otherwise it would make diagnosing and fixing clogging issues much easier, but it isn't as simple as the deflection angle of the cap iron being X. It is only X for a given shaving thickness and cap iron/cutting edge distance.

This is why you can get a plane that you're having trouble with sorted out perfectly well one day and be taking wonderful shavings, lulled into that all is right with the world feeling, but then the very next day without realising it you're taking shavings slightly thicker or thinner, or you're planing a different wood, or in a different direction relative to the grain, and the plane clogs again despite the cap iron position not having changed.

 

[Eric The Viking]

This is why you can get a plane that you're having trouble with sorted out perfectly well one day and be taking wonderful shavings, lulled into that all is right with the world feeling, but then the very next day without realising it you're taking shavings slightly thicker or thinner, or you're planing a different wood, or in a different direction relative to the grain, and the plane clogs again despite the cap iron position not having changed.

Purpleheart is my Cryptonite...

 

[D_W]

Dumb question from someone who only owns a couple of woodies (spokeshaves!): Does waxing the "wear" part of fhe throat help? It is end-grain after all, so I would expect shavings to catch on it by default.

Waxing can help, yes.

 

[Corneel]

This is not how the shaving deflects of the front edge of the chipbreaker:

The shaving doesn't follow the tangent of the chripbreaker edge, instead it immediately curls forward like in this picture from the Kato video.

The radius of that curl is quite tight, in the order of a couple of mm. Using more "capiron effect" increases this radius a little, but it doesn't really create a straight shaving in itself. The wear plays a major role in the creating the shape of the shaving. A plane without a wear (like a chisel plane) just makes tight rolls of shavings.

I don't think it is easy to find a formula for the ideal capiron and wear angles. It depends on too many factors, wood, grain direction, shaving thickness, wear angle, cap iron effect. Probably more...

BTW, I agree that thin shavings tend to clog the plane more then thicker shavings! My coffing smoother is a neuralgic clogger too. I really should look into this of these days. My previous smoother, a more modern day Nooitgedagt didn't have this problem at all!

 

[J_Cramer]

The wear plays a major role in the creating the shape of the shaving. A plane without a wear (like a chisel plane) just makes tight rolls of shavings.

There are certainly some interesting dynamics playing out in a plane. Here it looks like the curl is forming at the edge and at some point makes contact and - sort of- walks up the wear:

https://youtu.be/c0N5pV8N1H0?t=373


Cheers
Jürgen

 

[swagman]

Thanks Jurgen; that's an excellent video on the movement of the shaving.

regards Stewie;

 

[D_W]

8:00 point in that video shows what I mentioned in a different thread regarding the chip being directed into the wear and then ultimately straight up. You can see that even if the wear were steeper, the chip would still be directed out of the plane, but if the wear is too steep, just opening the mouth isn't optimal because it doesn't change that redirection of the chip. Relieving the wear a little bit instead does.

In the scenario just prior, the cap iron isn't set properly, and the chip is breaking up (still feeding out, but it's undesirable to have a plane shaving breaking as it suggests an interrupted cut, which makes dimensioning accurately more difficult.

Great video, by the way. As we discussed this prior, I never actually saw it in action. I just supposed it was happening since it's possible to get a plane with a steep cap iron to work.

If the shavings are thin, they should still come out, though they might be slowly forced up as a group rather than coming out cleanly as a single shaving.

A plane that doesn't clog on thicker shavings but does on thinner is a sign that you are close to having things set up correctly. It's relatively important for the function of a double iron plane that shavings stay uninterrupted (it's also better for planing if they do since you can control material removal better - if you've got tearout going on and you plane from left to right on a board, after a few passes, the part of the board with tearout will not be removed at the same depth as the part being cleanly planed - plus there's a good chance that you'll get stuck stopping to clean out a clog).

 

[nabs]

thanks Jürgen - what a fascinating video! graphic demonstrations of tear-out and the effect of the cap iron and also how savings form - really helpful and informative. I'll be having another go at working with my smoother this weekend!

 

[ac445ab]

Thanks for having shared the video. Never seen before.

I should have somewhere one of those German smoothers :mrgreen:

 

[Corneel]

Yes that was a nice and instructive video indeed.

 

[swagman]

https://www.youtube.com/watch?v=c0N5pV8 ... u.be&t=373

Modern advise recommends a steeper combined deflection angle closer to 90(+) degrees be applied to the front edge of the Cap Iron. If you view the above video at 7.00, that advise is being sorely tested.

If you view the video again at 8.00, you will note that steeper deflection angle on the front edge of the Cap Iron has been removed, in favor of what looks to be the manufactured angle of 30 degrees. Note also the leading edge of the Cap Iron has also been moved much closer to the front edge of the cutting edge, with a vast improvement noted in reduction of tear-out.

How close to the cutting edge the Cap Iron should be set is still open to conjecture. For the hand plane to be worked using an acceptable of force, a 2 stage process should occur. That is, the shaving is taken under the influence of the bed angle alone, before being further deflected by the Cap Iron. If one were to adopt the recent recommendations that the leading edge of the Cap Iron should be set within a very tight tolerance of 0.1 - 0.2mm, there lies an increased risk that a heavy shaving could easily change the force dynamics from a 2 stage process, closer to a 1 stage process, where the shaving is being influenced by the steeper combined angle of bed angle + Cap Iron deflection angle, resulting in an increase in force to work the plane.

 

[D_W]

I think you need to plane more than test boards. You're doing too much supposing and too little planing.

I didn't see anything in the video that claimed that either setting was optimal (stock or 90 degrees). the stock set couldn't have planed the shaving that the 90 degree set planed, either.

The 90 degree set is used in grain that is running out directly into the bed angle of the plane - the worse case scenario. The last set is a thinner shaving in a more forgiving piece of wood.

If you don't want to follow my advice on setup of the cap (remember how long I've been doing this), that's fine. I don't think you should be giving other people advice at this point, though. Not at least until you've built a few pieces of furniture with double iron planes and no thickness planer or jointer.

 

[D_W]

A couple of planes with wear angles that I don't recall, but I don't build planes with 90 degree wears. They are probably about what's been mentioned here.

https://www.youtube.com/watch?v=dtACbdWWgl4

Of course, the jack isn't going to clog on large shavings.

Watch for the try plane to clog (around 2:20 in the video). I set the cap iron up around 50 degrees or a shade more on this plane. It works exactly the way it's supposed to - the shaving deflects into the wear and then up and out. Brian sets the cap close and then takes a heavy shaving - he's tearout averse, to say in the least.

 

[D_W]

https://www.youtube.com/watch?v=c0N5pV8N1H0&feature=youtu.be&t=373

Modern advise recommends a steeper combined deflection angle closer to 90(+) degrees be applied to the front edge of the Cap Iron. If you view the above video at 7.00, that advise is being sorely tested.

If you view the video again at 8.00, you will note that steeper deflection angle on the front edge of the Cap Iron has been removed, in favor of what looks to be the manufactured angle of 30 degrees. Note also the leading edge of the Cap Iron has also been moved much closer to the front edge of the cutting edge, with a vast improvement noted in reduction of tear-out.

How close to the cutting edge the Cap Iron should be set is still open to conjecture. For the hand plane to be worked using an acceptable of force, a 2 stage process should occur. That is, the shaving is taken under the influence of the bed angle alone, before being further deflected by the Cap Iron. If one were to adopt the recent recommendations that the leading edge of the Cap Iron should be set within a very tight tolerance of 0.1 - 0.2mm, there lies an increased risk that a heavy shaving could easily change the force dynamics from a 2 stage process, closer to a 1 stage process, where the shaving is being influenced by the steeper combined angle of bed angle + Cap Iron deflection angle, resulting in an increase in force to work the plane.

mild apology for being a bit stiff in my response last night. I say mild because I should've been nicer. However, using the cap iron properly is such a simple thing if it's just done right. I think there's so much static and discussion about it that is so much more complicated and less subtle than just setting a cap up right and using it. The wood cap irons just work better at 50 degrees. They work some when they're thin and shallow, but not as well, and the video I showed of brian shows a close set that is basically finishing the work right off of the try. Brian follows that up with a japanese plane and light shavings, so there's no room for damage - he's engaging in risk free planing with the try plane, and the quality of the finish he produces shows an absolute top level planed finish.

A try plane works very well pushing the shaving into the wear and then out as long as it's set up correctly, there's no great reason to do it half way. In that video, if they subjected the shallow cap iron to the difficult wood that's shown with the 90 degree setting and at the same thickness, there would've been tearout, or the cap iron would've had to have been set too close to take a shaving that deep.

On the flip side of this "is 30 degrees the right setting", when this all first came out, I tested the entire range of cap angles and found stanley's stock angle to be about the best. Once you polish it, it's about 50 degrees. I tried 80, which is what every person concluded watching the kato video is a better set, but it isn't with a hand plane. It makes too narrow of a range where the cap iron works, and a little to close set and surface quality is terrible because the cap iron smashes wood back into the face of the board. If the cap iron isn't set close enough to that narrow range, then you still get tearout.

At 50 degrees, you get a wide working range where there is no tearout or no appreciable tearout. You can be lax and have limited tearout but little planing resistance, or you can set it dead on like Brian does and tolerate the extra resistance in order to plane risk free.

 

[tach]

mild apology for being a bit stiff in my response last night. I say mild because I should've been nicer. However, using the cap iron properly is such a simple thing if it's just done right. I think there's so much static and discussion about it that is so much more complicated and less subtle than just setting a cap up right and using it. The wood cap irons just work better at 50 degrees. They work some when they're thin and shallow, but not as well, and the video I showed of brian shows a close set that is basically finishing the work right off of the try. Brian follows that up with a japanese plane and light shavings, so there's no room for damage - he's engaging in risk free planing with the try plane, and the quality of the finish he produces shows an absolute top level planed finish.

A try plane works very well pushing the shaving into the wear and then out as long as it's set up correctly, there's no great reason to do it half way. In that video, if they subjected the shallow cap iron to the difficult wood that's shown with the 90 degree setting and at the same thickness, there would've been tearout, or the cap iron would've had to have been set too close to take a shaving that deep.

On the flip side of this "is 30 degrees the right setting", when this all first came out, I tested the entire range of cap angles and found stanley's stock angle to be about the best. Once you polish it, it's about 50 degrees. I tried 80, which is what every person concluded watching the kato video is a better set, but it isn't with a hand plane. It makes too narrow of a range where the cap iron works, and a little to close set and surface quality is terrible because the cap iron smashes wood back into the face of the board. If the cap iron isn't set close enough to that narrow range, then you still get tearout.

At 50 degrees, you get a wide working range where there is no tearout or no appreciable tearout. You can be lax and have limited tearout but little planing resistance, or you can set it dead on like Brian does and tolerate the extra resistance in order to plane risk free.

Late reply, but after reading this I went with a honing guide and set up my bog standard record plane cap iron at exactly 50 degrees, polished in a black arkansas, in addition to your unicorn method.

I can confirm that this worked exceedingly well, and got a shimmering finish in knotty whitewood while ejecting long ribbons of wood with just the holes where the knots were.
Thank you very much for sharing your knowldege & experience. I would have never thought this was possible before.

 

[thetyreman]

wtf is the unicorn method? did I miss something?

 

[tach]

wtf is the unicorn method? did I miss something?

It's basically grinding your main bevel at a lower degree angle, sharpen, and finishing the edge using a buffer to transform the edge into an apex much stronger than a straight line.

See


https://chisel-test.netlify.app/
https://inthewoodshop.com/WoodworkTechniques/TheUnicornMethod.html
And from David's mouth:


and follow up videos.

 

[Adam W.]

 

[Jacob]

wtf is the unicorn method? did I miss something?

Not missing anything.
It's an idea that D_W kicked off many years ago, which is still kicking around.
Amateur woodwork is full of clever ideas which should have been strangled at birth. They never die!
Check it yourself by all means
https://www.inthewoodshop.com/WoodworkTechniques/TheUnicornMethod.html

 

[thetyreman]

from what I can gather it's just a fancy name for microbevel, I'll be putting this on ignore then, what a load of codswallop, cheers.