Veritas planes

[Corneel]

Agreed! Anything that makes the process more efficient & enjoyable is good. I would like to sort this out, too.

I am thinking I should make a couple of cap irons and muck about with the the contact end until I crack the secret code (angle). My working hypothesis is that the angle the end of the cap-iron makes relative to the wood surface will turn out to be constant, i.e. it will become more acute as the pitch of the blade increases (at least for a given wood type). I've got planes with 3 different bed angles, so could test my theory to some extent. Of course it will take a fair bit of time, which I am rather short of right now, so I will be more than happy if you or someone else sorts it out in the meantime.....

Cheers,

No need to Ian, I allready did all the testing. When you read the above articles you'll find lots of different permutations, how they work, how well they work and even the forces involved and the rate of wear you can expect.

[planemaker]

Hi Corneel. Excellent report. I personally the reports final conclusions were thoughtfully laid out in a manner that made it reasonably easy to comprehend its content.

Some additional questions for you.

Did you reach any sort of conclusion on the relevance of a tightly set mouth to control tear out.

What role the cap iron plays in dampening vibration atypical within steel bodied hand planes.

And lastly.. Can we conclude from your report that the term cap iron is a much more accurate description to use, compared to that of calling it a chipbreaker.


regards Stewie;



Conclusions
The force measuring device proved to be a successful method to quantify some mechanical aspects of handplanes. The force Fc was measured with more variability than the force Fn, but both gave interesting results. The absolute values depend on a lot of other variables too, like wood type, cutting depth and grain direction. Therefore only the values relative to each other are meaningful.
The cutting force Fc in 60° and 55° planes is 31% higher than in a double iron plane with similar anti tearout properties. This is the force the user feels when pushing the plane forward.
The normal force Fn doesn’t change much in the double iron planes and remains negative, pulling the edge into the wood. In the high angle planes, Fn changes more rapidly and reaches zero around a 60° cutting angle requiring the user to force the plane into the wood surface rather than being pulled into the wood surface by the cutting edge.
The calculations of the frictional force are based on many assumptions. But still they show that the influence of the friction is small and doesn’t affect the above conclusions. The total normal force is quite similar for both plane setups and the small value of µk makes the influence of friction even smaller.
Tearout happens when planing against the grain, when the wedging action of the blade overcomes the bonding strength of the wood fibers, the force Fn is a measure of this wedge. In high angle planes this effect is reduced because the wedging action is reduced. With a shaving thickness of 0.05 mm and a grain angle of 4 degrees like in this experiment, the edge doesn’t act like a wedge anymore from 60° upwards.
Double iron planes don’t have this reduction of Fn, but they are equally capable of reducing tearout. The name of the chipbreaker suggests that it breaks the shaving before it can pull the wood fibers out of the wood, but a broken shaving wouldn’t press down on the edge either, and Fn would be reduced just like in a high angle plane. The shaving is a leaf spring which presses down on the face of the blade and the chipbreaker. This forms a resistance to the flow of the shaving, which increases when the radius of the shaving curl is tightened because of a steeper chipbreaker bevel or when the chipbreaker is set closer to the cutting edge. This resistance causes a counterforce which is transmitted through the shaving to the point where it is still attached to the wood. This counterforce supports that attachment and prevents tearout. This hypothesis is supported by the wear patterns in Kato’s article (1989).Further research is necessary to prove or dismiss this hypothesis.
The experiments with a dulling blade with force measurements and microscope images were interesting too. Fc increases at a similar rate for both high angle planes and double iron planes. Likewise there was not much difference between the length of the clearance wear bevels or the amount of edge recession. The only parameter which showed obvious different behavior is the normal force Fn. This increases twice as fast in the 60° plane compared to the 45° plane with the chipbreaker set at 0.1 mm from the edge over a distance of 100 meters. The handplane user needs to push the high angle plane down harder and this leads to more friction when the edge dulls.
The increase in Fn when the edge gets dull is often associated with the length of the clearance wear bevel. This doesn’t seem to be the case here, which leads to the conclusion that this microscope method isn’t useful to study differences in wear behavior between different plane setups.
The double iron plane has mechanical advantages over the high angle plane. It is easier to push and has a stronger negative normal force which feels like it cuts better with less down force. And while it dulls just as fast as the high angle plane, it doesn’t have the same rapid deterioration of the normal force. The true motives of the woodworkers of the 18^th century will probably remain a mystery forever, but this experiment demonstrates that the double iron plane is a technological step forward. For the modern woodworker that is useful to know too. http://planetuning.infillplane.com/html/mechanics_of_chipbreakers.html

[Corneel]

Hi Stewie,

In the first article I investigate the close mouth. To be honest, it was quite disapointing. You need a very tight mouth in the first place, certainly less then 0.3mm, probably less then 0.2 mm. In the curly walnut I only got results with a mouth as tight as 0.05 mm. High angles and close set capirons have much stronger effect. Another detail about the mouth, you must be absolutely sure that the sole touches the wood just in front of the mouth. This is the area of most wear, so it something to watch. I don't say that a tight mouth doesn't work, but as a method alone it is a bit disapointing.

I didn't do anything about vibrations, so I can't say anything about that.

And yes I think the term capiron is better, because the "chipbreaker" doesn't break chips in normal planing work. It works because it pushes the shaving back into the wood.

Greetings Kees

[derekcohen]

Stewie

Unlike Corneel, the reason I prefer the use of the term "chip breaker" is because "cap iron" is still synonymous with stiffening the blade, which has now been discredited. While "chip breaker" refers to the breaking or, rather, bending, of the chip - which is just another term for shaving. I could point you to a multitude of erudite woodworkers who also prefer "chip breaker". Indeed, I would say that Corneel is in the minority in his use of "cap iron". But use which ever you prefer.

Regards from Perth

Derek

[Corneel]

Stewie

Unlike Corneel, the reason I prefer the use of the term "chip breaker" is because "cap iron" is still synonymous with stiffening the blade, which has now been discredited. While "chip breaker" refers to the breaking or, rather, bending, of the chip - which is just another term for shaving. I could point you to a multitude of erudite woodworkers who also prefer "chip breaker". Indeed, I would say that Corneel is in the minority in his use of "cap iron". But use which ever you prefer.

Regards from Perth

Derek

Well, I am Dutch, so I far prefer "Keerbeitel". It really means: the chisel that returns the shaving. That's as accurate as it gets.

[derekcohen]

Keerbeitel? I think we should call it the "Keesbeitel" from now on!

(just a joke between Corneel and myself - I know him as Kees).

Regards from Perth

Derek

[planemaker]

Hi Stewie,

In the first article I investigate the close mouth. To be honest, it was quite disapointing. You need a very tight mouth in the first place, certainly less then 0.3mm, probably less then 0.2 mm. In the curly walnut I only got results with a mouth as tight as 0.05 mm. High angles and close set capirons have much stronger effect. Another detail about the mouth, you must be absolutely sure that the sole touches the wood just in front of the mouth. This is the area of most wear, so it something to watch. I don't say that a tight mouth doesn't work, but as a method alone it is a bit disapointing.

I didn't do anything about vibrations, so I can't say anything about that.

And yes I think the term capiron is better, because the "chipbreaker" doesn't break chips in normal planing work. It works because it pushes the shaving back into the wood.

Greetings Kees

Thanks Kees. Another question if I may. Is there an ideal acute bevel angle that should be used for BD single iron's on hand planes bedded at 50 & 55* that would work best to the reduce the effect of fc. The general rule only only mentions the importance of managing a clearance angle relative to the sole, and does not cover the optimum shear angle.

regards; Stewie.

[Corneel]

I think you can better ask that to Derek. He is more up to date on these. I get good results with my Ulmia plane, bedded at 49 degrees and close to 40 degree bevel angle on the keerbeitel.

Derek, your basterisation of the name keerbeitel could mean something really dirty in Dutch

[planemaker]

Well, I am Dutch, so I far prefer "Keerbeitel". It really means: the chisel that returns the shaving. That's as accurate as it gets.

Keerbeitel sounds an accurate term to use then Kees.

Stewie;

[planemaker]

I think you can better ask that to Derek. He is more up to date on these. I get good results with my Ulmia plane, bedded at 49 degrees and close to 40 degree bevel angle on the keerbeitel.

Derek, your basterisation of the name keerbeitel could mean something really dirty in Dutch

Thanks Kees. I was hoping you may have had some indication from the tests you carried out. The more acute the bevel angle the lesser the force (fc) required to maintain that depth of cut. Whether this bevel its hollow or flat ground would also have some bearing to the discussion.

Stewie;

[planemaker]

Hi Kees. Its 1.00 am in my part of the world. Signing off.

Stewie;

[Corneel]

Sleep well.

Regarding your last post. There is so much I would still like to test, but these things take a lto of time and I also wish to really make things again. I've got my eye onto soem Peter Follansbee stuff. I just watched his videos. One thing for sure. I am not going to worry about some tearout for a while.

[planemaker]

Sleep well.

Regarding your last post. There is so much I would still like to test, but these things take a lto of time and I also wish to really make things again. I've got my eye onto soem Peter Follansbee stuff. I just watched his videos. One thing for sure. I am not going to worry about some tearout for a while.

Hi Corneel. Have you seen Peter Follansbee's collection of early dutch carved hand planes. Very nice.

http://pfollansbee.wordpress.com/201...-dutch-planes/

[Corneel]

Hi Corneel. Have you seen Peter Follansbee's collection of early dutch carved hand planes. Very nice.

http://pfollansbee.wordpress.com/201...-dutch-planes/

Yes I've seen that. But it's not Peter's collection!

There is also a very nice collection in Holland in a museum.
http://www.openluchtmuseum.nl/ontdek...n/houtschaven/


My own "collection" of this type is a little small. I have one plow plane, made much later in 1874, but it is the same style. I also have a couple of 18th century moulding planes, but they are not so special and can be found easilly when you know what to look for.

[planemaker]

Hi Corneel. Referencing the 2 wing nuts that lock the fence arms in position on your plow plane. I dont see any evidence of mortise slides on either of the fence arms. Would I be right in thinking the wing nuts are fixed securely to the threaded studs.

Stewie.