Mechanics of chipbreakers and high cutting angles in woodworking planes. Abstract.

[Winton Applegate]

(I hope nobody ever breaks out the end of their lever cap on my suggestion to use it as a screwdriver.

I don't know about the iron. My gut is that since the screw hardly needs any serious torque to bed the chip breaker screw that the iron would be OK to use as well.
Speaking strictly about the bonze LN now I would say . . .
No not much chance of that. Their bronze is high quality and bronze is pretty tough stuff. It would get itzy bitzy little dings on it (that is what pains me) but no reason not to use it if the dings don’t bother ones sensibilities.

See you might think I didn't spend much time with my BDs but this is ACTUALLY how crazy I got (see photos). I bought a second screw driver and ground the end off a bit to make for a thicker blade.

As I always like to point out on tools when I can : the WF on the handle means it was made here in town at Western Forge.

Then one day I picked up the disc screw driver and it was simple; I didn't have to keep track of two drivers.

You think keeping track of a ruler is tough (not really) well two identical screw drivers with different thickness blades . . . well . . . don't try this at home friends . . .

I AM A PROFESSIONAL

[Kees Heiden]

I didn't know the capiron screw waranted a special tool. That's an opportunity! Now I use whatever screwdriver is close at hand, as long as it isn't one of these tiny electrican screwdrivers.

[Winton Applegate]

It is, in reality, a sinister communist anti commercialism plot to bring the American economy to its knees.
BU is dangerous. I use them in my lab under tightly controlled security to study world economics but the average crafts person should shun them. You have been warned.

tiny electrican screwdrivers.

Oh, those can be used as well just stick it side ways with the shaft in the slot.
But I do think you are right; there is a whole market there waiting to be filled or in layman's terms "tapped".
I'm thinking dial able, micrometer controlled, blade thickness dial with the optionally optional accessory USB data print out for forum discussion documentation verification.

Of course there will be a kit of tools to buy optionally optional to set up and tune the variable blade screw driver. And classes on how the pros set up the variable blade screw driver.

Heck, I'll buy one.

[Derek Cohen]

I didn't know the capiron screw waranted a special tool. That's an opportunity! Now I use whatever screwdriver is close at hand, as long as it isn't one of these tiny electrican screwdrivers.

Oh ... I've a special screwdriver for lever caps. 18C ...



Kees, has anyone suggested how wide the secondary bevel needs to be at the leading edge of the chip breaker? On a couple of planes, ones which did not perform well with LN chip breakers, the secondary bevel was "micro", that is, about 1mm wide. I had been treating the chip breaker as I would a plane blade. I had a re-think about this recently, and widened the secondary to about 6mm. This seems to have made a positive difference, and these planes are performing better. Any thoughts?

Regards from Perth

Derek

[Tom Vanzant]

I use a knock-off of the Glen-Drake plane hammer to adjust iron and wedge on woodies, and use the blade side on cap iron screws and my "Eclipse" guide.

[David Weaver]

I'm not kees, but I think that the bevel on the front of the chipbreaker needs to be of reasonable size, and not just tiny. I still like a rounded bevel better, but all of my rounded bevels are about 2-3mm long or so on vintage cap irons.

[george wilson]

Winton,I have forgotten to mention that those adjustable wrenches you posted a few days ago are classified as bicycle wrenches.

[Kees Heiden]

Have a look at the Kato video and at the picture about capiron wear in his article on Steve Elliotts site: http://planetuning.infillplane.com/h...ron_study.html

As far as I can see all the action takes place within 0.2 mm. After that the shaving curls away. But he didn't have a mouth, maybe that curls the shaving back again. I know when I plane certain types of wood I get dark spots quite a way up the capiron.

So, I guess your observation is a good one. Don't make it too tiny. I've always made it about 1 mm or so, but Stanley capirons are quite steep allready.

[Winton Applegate]

Hey !
What have I missed ?
I went back and read the first pages of this thread.

Sounded like more than I can catch up on according to the warning from Dave Anderson.
Trying out that planing technique sure cut into my forum time.
So what the heck, I may as well do what I can here . . .

showing an elimination.

OH MAN LETS NOT GO THERE. THAT’S JUST SICK David

I didn't agree, but didn't figure it to be a good time to be an inflexible jerk . . .

Hey . . . ANY TIME is a good time to be an inflexible jerk.
Here allow me to demonstrate :

"only a 30 reduction"

nooooooo
I said:

at it’s worst 30% more effort . . . (that means a lower percentage for many/ most some what less difficult applications

and

Your grasping at straws at this point

Yah soooooo ?


See how it’s done ? In flexible all the way. Now you try.

Steve V.,

Before I learned to set the chipbreaker, I got tearout; now I don't. My 45° and 50° double irons stop tearout better than than the 55° planes I've used, and they are easier to push. In fact, that is one way you know you've set the cap iron a little too close; if it feels like a 55° or higher plane, back it off just a hair. If you get tearout, you backed it off too much. The sweet spot is somewhere in between.

You can’t be saying stuff like that ! That is straight to the point and truly useful information for the newbie. WHAT ARE YOU THINKING MAN !
A paragraph like that could end this whole conversation, teach the poor newb what he / she needs to know and probably bring about world peace as a side effect.

We simply can not have this here !
Moderator !
Moderator !
Where’s the MODERATOR ?

Kees,

You're the first with real critique. Thanks for that. Critique is good and helpfull.

Was it Zig Ziggler who said in a talk something about him or his friend verify EVERY THING . . . yah I think he said his friend even proof reads the copies from the copy machine.
ha, ha, ha
The weird chip formation still bugs me and the fact that the other science dudes were getting it too . . . well . . . in spite of the success of the chip breaker . . . for me. . . brings into question those studies as well.

Adam,

I have no idea how anyone can do it with the old-style Stanley breakers. Every time I try, I get wood shavings shoved up under it. I'm not saying it can't be done, just that I don't have the skillz necessary to mate old-style breakers with blades that well.

Yah I have a real problem with manufacturers that put out a tool that must be precisely made in at least that one area to function I MEAN THAT IS THE WHOLE BLOODY POINT right ? This chip breaker. The chip breaker in the otherwise ordinary or rather frustrating and subpar plane, as planes go, . . .
The chip breaker is not completed.
The chip breaker is a do it your self “KIT PROJECT” that comes with a free plane with every purchase. No you have to finish the machining on the chip breaker.

The plane/chipbreaker should come with the following notice:
Dear customer:
You say you don’t know how to be a metal working machinist !?
You say you just want to be a fine cabinet maker and that you have devoted your life to learing that?
Well . . . the Stanley tool companie's official response to you is :
Too Bad Suckerrrrrrrr.

That ain’t right. I guess part of my problem with BD is just that.

I am a metal worker first so the chip breaker “PROJECT KIT” was no big deal for me. Meaning I had zero prob with shavings under the CB (until I tried the 3 thou. setting a few days ago). Back in the day after reading several sources of what I had to do I fettled it for no light and front edge hitting first while tightened down.
Not everyone can be so lucky.
Ha, ha,
Seriously Stanley ? ? ?
and from reading here about chip breaker settings on the order of .1 mm (.0039 inch) I may have more fettling/machining microscope aided work to do to mine. I was getting chips under mine in roughly speaking that range. I was at about .003 inch.

Or maybe the capiron lost its spring over the years?

Ha, ha,
How does that work ?
Metallurgically speaking ?
I would say it never had enough spring to start with.

When I was a young guy buying tools for various mechanical work, often at good guy prices offered by companies at the end of training courses, I would always buy spare parts for the tools and that ALWAYS included spare springs. You know for five, ten or twenty years down the line when the springs lost their spring and the springs were no longer available especially at the old and even reduced price.

I have NEVER needed even one of those springs.
I’m just saying . . .

the old breakers are unsprung.

So bent less.
That is a very good example of the terminology I used here some where :

Elastic deformation: meaning the cap iron flexed, sprung if you will, and flexed back to its original state when the screw was released to sharpen the blade or what not. LIKE IT SHOULD. LIKE IT WAS INTENDED. like it was designed and manufactured to do by a competent company.

Plastic deformation: meaning the cap iron was stressed, failed to accept those stresses without permanent change in its shape, bent (or unbent) if you will, and FAILED to flex back to its original state when the screw was released to sharpen the blade or what not. A PRODUCT FAILER . This was never INTENDED by the manufacturer (we hope).

Does the latter translate into a design and manufacture by an INCOMPETENT company? Probably not but why make the CB so soft ?

Also

turning the levercap screw a quarter of a turn tighter can increase the pressure to prevent shavings from entering under the chipbreaker.

See now I have to tighten the screw well and that means I don’t have another 1/4 to work with really. I experimented with that way back and found the blade slips along the cap iron if it isn’t tight.

Adam ,
it is important that the part of the underside of the cap iron meets the blade at an angle so the forward most edge is on the blade with clearance behind because when you tighten the screw it rocks the underside of that fettled surface and can lift the forward most edge off the blade a hair. So in other words even your chip breaker edge needs back clearance. Simple huh ? Ha, ha, not really huh ?
It is all worth it though. Now you . . . chant with me “It is all worth it ? “
Wait
I mean
“It is all worth it ! “ “It is all worth it ! “

David W.,
You completely lost me when you said

like a rounded bevel better, but all of my rounded bevels are about 2-3mm long or so on vintage cap irons.

Don't the fibers slip under then ?

Of course, I could just tell my wife that the old blade/breakers need replaced in my #2 and 603

Best to tell her you are taking her out for a burger. The less discussed about hand planes the better. I think the others here will at least agree with me on that.

David W.,
.

I've never seen the depth of that wear stated in thousandth

I don’t know but I am thinking at least measured in .0000 decimal places and probably .00000 decimal places. One thousandth is like a mile when it comes to wear at the edge and that is part of my point when banging on about not rounding the blade edge during sharpening in my past threads.

I am now in love by the way . . . with the “Chinese 12k” stone.
some what bares out what I have said in the past (barring cutting hair on the face) about slurry for the most part being a mistake and that the OLD Norton 8000 WAS a great stone.

exemplifies the danger of coming to a conclusion over pictures.

Oh now . . .
let me have my little moment of discovery without raining on my parade.

In the past I have compared the double iron to using hot hide glue, pole vaulting, and playing the violin.

All at once ?
Funny you should mention that . . . I HAVE BEEN attempting to glue together a violin with hot hide glue, then play it ALL the WHILE pole vaulting. I keep getting glue in my eyes and then when I land the pole hits me in the back of the head.
But I’m getting there.

What is my next great challenge you may ask ?
I am looking at that . . .
I think maybe I’ll try convincing the average person on the street, chosen at random, that there is a direct correlation between all the energy released as heat and pollution by them driving to the next town to work every day, added to their demanding that their cloths be made from cotton grown in one part of the world, shipped half way around the world to be made into cloth in China, then shipped half way back around the world to them to be worn and all the energy released as heat and pollution by that has anything at all to do with climate change.

The fact that the cloths are still cheeper than can be produced in the same country the cotton and the manufacturing is done in (e.g., America) without all the ridiculous shipping and handling even I can’t explain . . . even if I get a longer lighter carbon fiber pole.

Ahhh...I wasn't looking at what I thought I was looking at.

I hate when that happens.

Adam,
I

've torn out with a bevel-up plane just like a bevel-down. The only difference is by moving a chip-breaker closer to the edge, I can tone down tear-out with a double iron whereas bevel-up is just too fickle for me. So, hopefully with a few more years, all this will be second-nature (or close).

Then you need to bend it. Oh wait that is the BD
Well you need to overhaul the plane with screw drivers. No that’s BD
Well you need to order BETTER parts. No . . . that’s BD

Speaking of BU now
You need to put the blade back in the sharpening jig, (you ARE using a sharpening jig so you have some reference of what altitude you are flying at right ?) . . . set the jig maybe five degrees steeper , take about four or five strokes down your finest stone and lock and load.

No you won’t need your screw drivers that was for that other plane.

When you get no tear out you will have honed at the correct angle.
There will be a point when you get no tear out unless your blade back is not flat or you have been remiss in your stone care and sharpening duties.

And what can I say? I'm a masochist. :P I actually like steep, steep learning curves and having to solve problems.

Then from what everyone here tells me, about my self, you are going to simply ADORE the BU with a steep sharpening angle. Except for the learning curve being steep or a problem. That will bore you very quickly in its lack of challenge and complexitude.
Can’t have every thing.

[george wilson]

Winton,I can hardly make sense of this very long post.

About springs: I will mention that I had to recently stretch the coil trigger spring of my 1907 BSA air rifle; It had lost its ability over the years to keep the trigger from slipping out of the sear,making it impossible to keep the gun cocked. A little stretching has restored it to its proper function. That,and a few other similar instances have led me to believe that metal springs(and lower grade steel parts like the chip breaker) can get a bit tired over time,and need re bending,stretching,or whatever. I think it depends upon the type of spring,type of steel,etc.. The 50 round drums of loaded Thompson sub machine guns seem to still function 50 or 60 years being wound under tension full of ammo. But,that's a very long clock spring type of spring,which,being long,is not subjected to the same strain as a shorter spring,or a chip breaker(which is not as good a steel as spring steel).

[Winton Applegate]

I can hardly make sense of this very long post.

You will have a lot of company in that I am sure.
I think individuals may see in the quotes their own post and so may pick and choose as if at a rather past its prime buffett. That was the best I could do.
I was sure my house would have been fire bombed, and with good reason, because of the sheer bulk of frame work around each reply that would have been added to the thread if I had made individual "Reply"s to each post I wanted to reply to.
And as you must realize by now for me to remain silent is an impossibility, for good or not so good.
Distracted for a time by other interests yes. Standing by silently (and wisely) observing ? Nah, ain't gonna happen.

I think I have, here today, set a personal record for sheer volume of postage which, I think was only rivaled for its sheer ______ness by my post were I was able to use ALL of the paste in face expressions available here in one post. Ahhhh that was a good one . . .

about the Magnum Copious post all I can say is . . . don't worry . . . it wasn't important.

[ian maybury]

So far as i know springs (and the cap iron is basically a leaf spring) will definitely tend to relax George - it happens all the time with car and motorcycle suspension. There's often an initial set when the load is first applied - if parts of the spring are not properly heat treated, or were locally softened by heating as a part of a post forming process they may 'give' because the yield stress was exceeded in these areas despite the overall loading being within the nominal design spec. This tends to happen more or less on first loading or soon afterwards, is likely to be stable/not to worsen.

More interestingly it seems that steel held under stress for long periods creeps or relaxes - that's at stresses well below the elastic limit or yield. The amount is determined by the stress level - how close to yield it gets. Temperature plays a role as well - it's worse at higher temperatures. Properly designed springs made from uniformly high quality and properly heat treated steels and loaded to a lower proportion of their strength do much better (and vice versa) - basically because at maximum deflection they typically are not so highly stressed relative to their (higher) yield strength...

The theory is that steel is elastic to its yield point. That may be the case in a tensile test sample of uniform composition and heat treatment, but my own experience having done some testing of welded up highly stressed steel tube structures is that they in practice don't necessarily behave all that elastically at all. Much more as though both of the above factors overlay the underlying elastic characteristic - which they almost certainly do. Confused the hell out of me, and a nice example of a situation where there can be significant differences between taught/presumed application of theory and a rather more complex reality...

[Kees Heiden]

Stanley capirons certainly aren't made of "uniformly high quality and properly heat treated steels". No idea what they are made of, but it is a rather soft, gummy metal that creates huge and persistant wire edges when you work on the bevel. So that would explain their sagging under the constant pressure of the levercap over a 100 years or so.

[Kees Heiden]

Kees,

Was it Zig Ziggler who said in a talk something about him or his friend verify EVERY THING . . . yah I think he said his friend even proof reads the copies from the copy machine.
ha, ha, ha
The weird chip formation still bugs me and the fact that the other science dudes were getting it too . . . well . . . in spite of the success of the chip breaker . . . for me. . . brings into question those studies as well.

I just ran out to the shop and did a little test on some maple with my blockplane. You can see two shavings in picture. They are both the same length. The one on the left is with a normal mouth (0.5 mm or so), the one on the right is with the mouth fully open like you can see.

So as you can see, this curling is normal behaviour in a plane, also a bevel up. The shaving on the left also starts with a tightish curl, but then it hits the mouth and it is pushed upwards.

I had to experiment a bit. This behaviour depends on the shaving thickness too. This one happens to be 0.09mm thick.

All my tests with each plane setup produced the same curling shavings. So I think the results are valid relative to each other. And now I can produce a similar shaving with a bevel up plane too, I think we can also conclude that the results are valid for bevel up planes too.

Another conclusion is that the mouth is important to guide the shaving upwards out of the plane. Hardly surprising, that conclusion, but still fun to watch it happen.

Curl.jpg

[Kees Heiden]

Here is the table from the article from Akinori Yamashita. It tells us how to make the mouth to avoid clogging with a double iron plane.

Some explanations. P is the "chip guide". We call this the wear. That is the front wall of the mouth in front of the cutting edge. The height of the wear was 10 mm.

Shaving thickness was 0.04 mm. Capiron bevel angle was 50 degrees. Bedding angle of the plane 40 degrees.

The crosses in the table present a clogging situation. The triangles are the rolled up shaving like in my previous post and the circles are proper shaving discharge.

Behaviour was the same for planing against the grain and parallel to the grain.

0.2 mm mouth width is a value where you can expect anti tearout behaviour.

Hope I didn't forget anything!

Table.jpg