I don't get why all plane irons aren't laminated?

[Jacob]

..........
And a word about cap/breaker/double irons: the purpose of this invention is the improvement of cutting performance and surface quality left by the blade, through altering/modifying the cutting geometry. A properly set double iron behaves like a higher pitched blade, but the cutting force remains almost the same. Improved rigidity is a mere bonus.

Have a nice day,

János

So would a cap iron improve the cutting performance of a bevel up plane, through altering/modifying the cutting geometry? And if not, why not?
NB it's not "rigidity" that's the issue IMHO. It is the firm grip near the edge, pinning the blade to the frog and back of the mouth. Amounts to the same thing I suppose.

 

[bugbear]

..........
And a word about cap/breaker/double irons: the purpose of this invention is the improvement of cutting performance and surface quality left by the blade, through altering/modifying the cutting geometry. A properly set double iron behaves like a higher pitched blade, but the cutting force remains almost the same. Improved rigidity is a mere bonus.

Have a nice day,

János

So would a cap iron improve the cutting performance of a bevel up plane, through altering/modifying the cutting geometry? And if not, why not?

I don't immediately see any way to get the cap-iron to sit ON THE BEVEL to get it close enough to the edge to effect cutting.

And (God forbid) such a design would appear to require a consistent bevel over time. :wink: :wink: :wink:

BugBear

 

[Jacob]

..........
And a word about cap/breaker/double irons: the purpose of this invention is the improvement of cutting performance and surface quality left by the blade, through altering/modifying the cutting geometry. A properly set double iron behaves like a higher pitched blade, but the cutting force remains almost the same. Improved rigidity is a mere bonus.

Have a nice day,

János

So would a cap iron improve the cutting performance of a bevel up plane, through altering/modifying the cutting geometry? And if not, why not?

I don't immediately see any way to get the cap-iron to sit ON THE BEVEL to get it close enough to the edge to effect cutting.

BugBear

Same as an ordinary one but with bit of an extra long curl at the end?
My point was that I don't think it'd have any effect and Janos's theory is wrong.

Confident statements abound, in woodwork fora as elsewhere. They should be received with some scepticism. I've just been googling "cult of expertise". :shock:

 

[Corneel]

I have some older woodies with a single blade, bedded at 45 degrees. They are definitely more tearout prone then the other planes with chipbreaker. At the other hand, for me, the chipbreaker isn't the end-all solution against tear out. A higher pitched blade works better in that area.

So for smoothers a 50 degree bedded plane is a good investment ( I paid about 10 euro for my Ulmia Reform smoother). The real problem is with the other planes like the jacks, fores and jointers. A 45 degree angle is very nice to have, because it takes less energy to push the plane. And higher pitched ones are very rare or very expensive. In that kind of plane a chipbreaker helps to reduce the amount and depth of the tear out, making it easier to get the board smooth with the smoother.

Cambered blades aand chipbreakers are another problem. So i'm thinking about making a nice wooden jackplane with a single blade and 50 degree angle.

 

[bugbear]

..........
And a word about cap/breaker/double irons: the purpose of this invention is the improvement of cutting performance and surface quality left by the blade, through altering/modifying the cutting geometry. A properly set double iron behaves like a higher pitched blade, but the cutting force remains almost the same. Improved rigidity is a mere bonus.

Have a nice day,

János

My point was that I don't think it'd have any effect and Janos's theory is wrong.

Confident statements abound, in woodwork fora as elsewhere. They should be received with some scepticism. I've just been googling "cult of expertise". :shock:

The effect of cap irons on cutting geometry (and results) has been confirmed experimentally (by an diligent and careful Japanese scientist), although the distance from the cap iron to the cutting edge needs to be rather small.

BugBear

 

[Jacob]

.....
The effect of cap irons on cutting geometry (and results) has been confirmed experimentally (by an diligent and careful Japanese scientist), although the distance from the cap iron to the cutting edge needs to be rather small.

BugBear

Link?
This sort of idea? http://www.leevalley.com/en/shopping/in ... px?p=48492
So would it work on a BU plane (yes it'd have to be turned a bit to sit on the bevel in an equivalent position)?
I guess it might, but that for most planes it is set back too far and it's primary purpose is the edge hold down, not needed so much on a heavy bladed steel BU plane.
When I've tried a very close set cap iron it has hindered rather than helped. To be realistic it'd have to be not only close but also very carefully shaped and fitted to match the curled turned edge of a scraper blade. IOW a perfect detail, hypothetical possible, not practical.
Having said that I'll try again!

 

[bugbear]

it'd have to be not only close but also very carefully shaped and fitted to match the curled turned edge of a scraper blade.

The angle you're thinking of (to turn up and break the shaving) is made between the edge of the cap iron and the back of the blade in a BD plane.

No fancy shaping is needed.

Edit; here's my "how to tune a cap iron" picture again:

Top image shows clearly shows how the cap iron would turn the shaving up at a steeper angle than the blade.

BugBear

 

[Corneel]

Yes it's finicky. But it saves energy when pushing the plane and it leaves a nicer finish.

Regarding the finickyness, it helps to set the capiron a bit further from the edge, fasten the screw and then set the capiron to the required position with a small hamer.

 

[Jacob]

it'd have to be not only close but also very carefully shaped and fitted to match the curled turned edge of a scraper blade.

The angle you're thinking of (to turn up and break the shaving) is made between the edge of the cap iron and the back of the blade in a BD plane.

No fancy shaping is needed.

My point was that to fit a cap iron to a BU blade you would need to shape it to reach over the bevel to the edge. I doubt anybody would bother, even in the interests of plane science! But if it works for a BD blade it should work the same for a BU blade, the EP angle being the same in each

I've just had a go with a closely set cap iron <0.5mm on a BD plane. It doesn't improve the cut particularly it just changes a fine cut into something approaching a scrape, which is what you'd expect. It also makes a deep cut much harder work. No point really. The normal 1/16" is fine.

PS I get the opposite effect that Corneel gets i.e. more work not less. :shock:

 

[bugbear]

I've just had a go with a closely set cap iron <0.5mm on a BD plane. It doesn't improve the cut particularly it just changes a fine cut into something approaching a scrape, which is what you'd expect. It also makes a deep cut much harder work. No point really. The normal 1/16" is fine.

Any of the old texts will point out that a cap iron very much closer than the shaving thickness will cause trouble, probably jams. Adjusting cap iron gap appropriately is part of correct plane setup.

The close fits are for tear out reduction when taking fine cuts on tricky wood - it's a cost-benefit thing, since getting everything working with a close fit cap iron is finicky.

Horses for courses.

BugBear

 

[János]

Dear Jacob,

You misunderstood something: I have never ever seen a bevel up plane with cap iron. In metallic bevel up planes there is a so called lever cap, but that is not the same thing (as you surely know that :wink: ). The development of double irons in traditional, bevel down planes is far from being well documented, but the bevel up plane configuration itself was a late XVIIIth, early XIXth century development.
The effect of chip breakers in woodcutting tools was researched and documented by German, Russian and American scientists of the late XIXth early XXth century. Unfortunately, my books on woodworking tool theory are in my native language.

A fast search of the web resulted in this:

http://ir.library.oregonstate.edu/xmlui ... sequence=1
http://woodtools.nov.ru/mag/understandi ... ood_id.htm

And Holtzapffel mentioned double iron planes in his magnificent opus:

http://www.wkfinetools.com/hUK/Holtzapf ... -Vol.2.pdf

The name “chip breaker” is a misnomer, tough: it was borrowed from metalworking terminology. In a handplane the breaker iron seldom breaks the shaving into chippings (a very heavily set /2~3 mm cutting depth/ plane can produce these fragmented chips, however) but abruptly bends it over instead, crushing the internal structure of cellulose fibres forming the cell walls.


Have a nice day,

János

 

[Jacob]

Dear Jacob,.......I have never ever seen a bevel up plane with cap iron.
........

Nor me. But if it works for a bevel down plane (improves cutting, nothing to do with rigidity etc) it should work the same for a bevel up plane (with the same effective angle). So why is it not done?
Don't think I've misunderstood anything so far!

 

[János]

Dear Jacob,

Perhaps, because it would be quite pointless and impractical, I think, just like welding a hardtop to a Ferrari spider. But in theory, it would work flawlessly.

Have a nice day,

János

 

[ali27]

Thank you everybody for the responses.

I think I have seen quite a few expensive BD infill planes without
chipbreaker that work excellently, which shows that the chipbreaker
is not needed.

For me an ideal plane blade is lamnated and is rigid enough
to not need a chip breaker.

Ali

 

[Corneel]

improve[/i] the cut particularly it just changes a fine cut into something approaching a scrape, which is what you'd expect. It also makes a deep cut much harder work. No point really. The normal 1/16" is fine.

PS I get the opposite effect that Corneel gets i.e. more work not less. :shock:

I wonder at what angle the front of your chipbreaker is? If that is too steep I can also imagine the results you got.

But I won't argue too much because I am absolutely no chip breaker expert. I just feel that a close fitting chip breaker gives better results without increasing the workload.

 

[bugbear]

Dear Jacob,.......I have never ever seen a bevel up plane with cap iron.
........

Nor me. But if it works for a bevel down plane (improves cutting, nothing to do with rigidity etc) it should work the same for a bevel up plane (with the same effective angle). So why is it not done?

Because nobody's come up with a way to fit one that works well enough to justify the cost and effort. In any case, with a BU design, it's easy to increase the effective pitch, which achieves a similar end result.

BugBear

 

[Jacob]

Dear Jacob,.......I have never ever seen a bevel up plane with cap iron.
........

Nor me. But if it works for a bevel down plane (improves cutting, nothing to do with rigidity etc) it should work the same for a bevel up plane (with the same effective angle). So why is it not done?

Because nobody's come up with a way to fit one.

BugBear

Easy peasy - they just haven't tried.
Mainly because there would be no point - BU blades are always heavy and firmly held down so they don't need the extra hold-down effect of the cap iron.
There would be a point if the cap iron actually did improve cutting in other ways as Janos says they do, but they don't.

 

[bugbear]

Easy peasy - they just haven't tried.
There would be a point if the cap iron actually did improve cutting in other ways as Janos says they do, but they don't.

If you have an idea to make such a cap iron, put up a sketch - I've already explained why it isn't done in practice, the cost-benefit doesn't work out.

Evidence in favour of the cap-iron effect on cutting has already been cited.

BugBear

 

[Vann]

...BU blades are always heavy and firmly held down so they don't need the extra hold-down effect of the cap iron.

Not so. My Stanley and Record block planes (#110, #0120) are bevel up, and have irons as thin as, or thinner than, my bevel down planes from the same makers. I.e. less than 2mm thick.

Cheers, Vann.

 

[dunbarhamlin]

Given the plethora of weird and wonderful plane related patents, I'd be surprised if a chip breaking cap iron hadn't been devised for a BU plane - there's a fellow who posts on WoodNet who's catalogued a lot of these - could anyone summon up the energy, could be worth posting there (with patent in the subject to attract the fish )