removing a back bevel

[G S Haydon]

No need to apologize. I just like to understand things clearly. Most spindle machine tooling is carbide or HSS, it spins quickly and can often take very deep cuts. HSS and Carbide are not often found in hand tools which work under less pressure. I found it hard to draw exact parallels between the two. Yes they both remove wood but in a different fashion. I'm not saying you're wrong, some evidence might be good if anyone can find some.

 

[woodbrains]

A handplane excerts something like 0.5 kgf per mm on the cutting edge. We are happy if we can take a 0.1 mm thick shaving at 1 meter/second.

A router rotates at 14000 rpm. Say, we have a bit with a 4 cm circumference. That translates to 10 meter/second. You can easilly take a shaving 10 times as thick. So the total force at the cutting edge might be 100 times as large.

No idea how that translates to pressure at the micron level.
Tungsten carbide is quite a bit more wear resistant then carbon steel of course.

So, who knows, Mike might be right after all!
Cracking tool steel. And when the grooves made by sharpening are less deep and less abrupt, that means less stress on the carbides.

I still would like to see all the evidence on the Internet though.

Hello,

This is more like it, some logical progression, not just random disbelief :shock:

The rate of cut is not relevant here, this would be good for comparing abrasion resistance in one material to another, but not indicated in pressure at the cutter tip. I don't think shaving thickness has everything to do with this either, that indicates the power of the motor doing the pushing. I am not strong enough to make a 1 mm thick shaving with a hand plane, but a horse might; the cutter is capable of doing it, for sure. And who knows if a spindle is making a 1 mm cut, or just cutting to the depth of 1 mm in lots of little bites? My spindle makes confetti not matchsticks. The thickness of the shaving might have an effect on the pressure at the extreme edge of the cutter, but this is hard to calculate since a lot of the pressure will be exerted elsewhere on the cutter or chip breaker or whatever. From an observational point of view wood is cut by machine or hand tool in the same order of size of chips and so I think it may be sensible to contend that the cutters undergo similar amounts of pressure. I do think abrasion can be compared within reason as far as the edge of the tool is concerned.

Mike.

 

[G S Haydon]

From an observational point of view wood is cut by machine or hand tool in the same order of size of chips and so I think it may be sensible to contend that the cutters undergo similar amounts of pressure.

That's interesting. My extraction bags have quite a different size and type of chip when compared to my hand tool sweepings.

 

[woodbrains]

From an observational point of view wood is cut by machine or hand tool in the same order of size of chips and so I think it may be sensible to contend that the cutters undergo similar amounts of pressure.

That's interesting. My extraction bags have quite a different size and type of chip when compared to my hand tool sweepings.

Hello,

But still in the same order of size, I think you'll agree, not like a pebble to a brick, or a brick to a house. All chips can be measured in tenths of mm.

The power of machines is more to do with the size of the cutter it pushes than the size of the chips produced. My planer has a 12 inch cutter. I cannot push a plane with a 12 inch iron even if the shaving is tissue thin. The planer has the power to plane a 12 inch wide board, but he shavings are not mm's thick even if it removes that much material. They are the same order of thickness.

Mike.

 

[Corneel]

Speed is higher in powertools, which makes quite a difference in temperature. They use completely different toolsteels. Rake angles and sharpening angles are different. Just saying, always be carefull with comparing things. Another important aspect, powertool edges are sharpened with relatively coarse abrassives. Handtool owners usually take the extra effort to use a highr grit waterstone, or a strop with or without a polishing compound. Powertools are just grinded. That gives much coarser scratches, so also, maybe, more trouble with micro fracturing.

I am still not convinced that abrasive wear isn't a major factor in handtool edge wear. For several reasons. It is mentioned in every single article about toolwear in wood cutting. Not as just a word, but as a mechanism, contrasted with adhesive wear, chemical wear and fracturing. I read somewhere (forgot which article) that there is never a single wear mechanism active, so I don't rule out micro fracturing either. Another reason why I think that abrasive wear is an important factor is the removal of tool steel relatively far away from the edge. On the face side, where the shavings are just rubbing over the steel, a lot of metal disappears and a deep wearbevel is created. Temperatures are certainly a lot less up there, and the steel isn't so vulnerable as at the edge. I don't think the minerals in the wood can grind the carbides, but I think they can do something with the iron molecules making up much of the volume of carbon tool steel.

Anyway, you have a hypothesis. According to your hypothesis, a natural stone like a hard Arkansas leads to meaningfully longer edge life then a 6000 or 8000 grit waterstone. Now we only need an experiment to valuate your hypothesis. Or not.

 

[MIGNAL]

Even if it does give a longer lasting edge it's probably very marginal and outweighed by the Arkansas taking longer to remove metal.
I have a 8,000G waterstone, Arkansas, slate and a few others of very fine grit. If my experience was such that one of them resulted in edges that lasted significantly longer I'd be using that one particular stone. As it is I use my waterstone and when that is finally down to nothing I'll switch to my slate.

 

[woodbrains]

Even if it does give a longer lasting edge it's probably very marginal and outweighed by the Arkansas taking longer to remove metal.
I have a 8,000G waterstone, Arkansas, slate and a few others of very fine grit. If my experience was such that one of them resulted in edges that lasted significantly longer I'd be using that one particular stone. As it is I use my waterstone and when that is finally down to nothing I'll switch to my slate.

Hello,

You are right, if there was a big difference it would have jumped out at me and I would not need others experiences to verify, or disprove what I think. But then again, lots of different little improvements all add up to something worth having. Forged steel such as in Clifton plane irons have a bit of an advantage because of grain alignment and the thicker iron being stiffer a little more, so additively, there may make a big difference. Or not.

Speed is higher in powertools, which makes quite a difference in temperature. They use completely different toolsteels. Rake angles and sharpening angles are different. Just saying, always be carefull with comparing things. Another important aspect, powertool edges are sharpened with relatively coarse abrassives. Handtool owners usually take the extra effort to use a highr grit waterstone, or a strop with or without a polishing compound. Powertools are just grinded. That gives much coarser scratches, so also, maybe, more trouble with micro fracturing.

I am still not convinced that abrasive wear isn't a major factor in handtool edge wear. For several reasons. It is mentioned in every single article about toolwear in wood cutting. Not as just a word, but as a mechanism, contrasted with adhesive wear, chemical wear and fracturing. I read somewhere (forgot which article) that there is never a single wear mechanism active, so I don't rule out micro fracturing either. Another reason why I think that abrasive wear is an important factor is the removal of tool steel relatively far away from the edge. On the face side, where the shavings are just rubbing over the steel, a lot of metal disappears and a deep wearbevel is created. Temperatures are certainly a lot less up there, and the steel isn't so vulnerable as at the edge. I don't think the minerals in the wood can grind the carbides, but I think they can do something with the iron molecules making up much of the volume of carbon tool steel.

Anyway, you have a hypothesis. According to your hypothesis, a natural stone like a hard Arkansas leads to meaningfully longer edge life then a 6000 or 8000 grit waterstone. Now we only need an experiment to valuate your hypothesis. Or not.

This is all true, I never denied it. I only wanted to concentrate on the micro fracture aspect and the heat aspect of tool wear because it was pertinent to the notion of consolidation and smoothing I was toying with. The rest happen regardless and in whatever degrees in whatever tools. I don't want to get bogged down with the other effects that cannot be affected by the sharpening process. For instance, sharpening can have no bearing on the cutters speed so was disregarded, I don't think sharpening could have an influence on the adhesive effect of the material either, so again disregarded. At the moment the tool is sharp from the stone, what is its condition and is it different with different sharpening media, is what I want to know. If that tool is subsequently used to butcher meat, remove paint, shave hair, carve stone, neither I nor the sharpening gear care.

Mike.


Mike.

 

[Jacob]

...... lots of different little improvements all add up to something worth having. Forged steel such as in Clifton plane irons have a bit of an advantage because of grain alignment and the thicker iron being stiffer a little more, so additively, there may make a big difference. Or not.

Hmm I think not

I have thought about it some more, and my idea of this causing work hardening might not be the only explanation as to why there might be a better edge retention to the tool. There might be some sort of healing effect.

Interesting. There have always been, in the course of human history, people who believe in the power of various stones to have impact on the treating of many ailments, be they mental, emotional or physical.
Sharpening too?
Is this what Stonehenge is all about? A massive centre for tool healing? :shock:
I'm going to get on down there and rub a Stanley against a blue stone at the earliest opportunity.

Has anybody considered sharpening and the phases of the moon? It could have a bearing on grain alignment.

 

[woodbrains]

Hello,

Nice editing for comic effect there, Jacob! But then you've never let context get in the way of how you choose to reply. :shock:
Mike.

 

[Richard T]

It's nonsense of course.


Everybody knows it's pyramids that do that.

 

[Harbo]

Anyway the stones are fenced off!

 

[iNewbie]

Is this what Stonehenge is all about? A massive centre for tool healing? :shock:

Yet they found no cure for you. :mrgreen:

 

[Carl P]

Is this what Stonehenge is all about? A massive centre for tool healing? :shock:

Yet they found no cure for you. :mrgreen:

I hope you're not suggesting Jacob is a bit of a tool! Still, at least we know the true meaning of stonehenge - a giant sharpening jig, they certainly had impressive tools in those days.

Cheerio,

Carl

 

[Corneel]

Nice picture Jacob!

 

[iNewbie]

Who me, Carl? :lol:

He knows I'm gesting. He's a touch rabid about sharpening though.

 

[Cheshirechappie]

After a bit of reflection, I think we may have some difficulties finding academic studies of the behaviour of carbon and low-alloy steels (such as O1, A2 etc.) when ground or honed. The reason for this is that industry moved away from their use as machine cutters in the metal industries about a century ago, and their use as machine cutters in the woodworking industries declined several decades ago as well. Academic studies tend to be directed to areas where there could be economic benefit, and as the vast majority of both wood and metal are machine-worked, that's where the research grants will be directed - and they tend to use harder materials such as cemented carbide inserts and the fancier cermets, even increasingly for wood-machining. The poor old hand-tool industry is 'niche', and has been for many decades, so with the occasional exception like Rob Lee self-funding an objective comparison between potential hand-tool steels, there will be very little to find.

So how do we answer questions like those posed above? Not really sure, to be honest - but some investigation of basic steel metallurgy, and the structure and chemistry of man-made and naturally-occuring stones that make good hones may yield something.

The other option is to formulate and conduct experiments and investigations ourselves. Some may enjoy that challenge, but I'm afraid it's a step too far for me - I don't want to commit the time and resources it would need. I wish anybody that does good luck, though, and I'd be fascinated by any results that did emerge.

 

[Jacob]

.... The poor old hand-tool industry is 'niche', and has been for many decades, so with the occasional exception like Rob Lee self-funding an objective comparison between potential hand-tool steels, there will be very little to find.

Paul Sellers self funded video here- comparing different planes/steels and concluding that there's not much in it. We already know that, let's face it!

So how do we answer questions like those posed above? .......
The other option is to formulate and conduct experiments and investigations ourselves. ......

Every time we pick up and use/sharpen a tool this is an experiment/investigation. We are all at it! Unless/until someone can demonstrate an advantage or other phenomenon worth investigating, there is nothing new to investigate.

 

[Cheshirechappie]

..... there is nothing new to investigate.

Oh come on, Jacob! The fact that people were posing questions above that we couldn't give full answers to disproves that one!

Science is a very long way indeed from knowing everything.

 

[Corneel]

.... The poor old hand-tool industry is 'niche', and has been for many decades, so with the occasional exception like Rob Lee self-funding an objective comparison between potential hand-tool steels, there will be very little to find.

Paul Sellers self funded video here- comparing different planes/steels and concluding that there's not much in it. We already know that, let's face it!

So how do we answer questions like those posed above? .......
The other option is to formulate and conduct experiments and investigations ourselves. ......

Every time we pick up and use/sharpen a tool this is an experiment/investigation. We are all at it! Unless/until someone can demonstrate an advantage or other phenomenon worth investigating, there is nothing new to investigate.

That's gaining experience. Very important and usefull, but it is not a scientific experiment. Because it is not controlled and it is subjective. Results from scientific experiments are usually very dull, only measuring one small fact under very controlled circumstances.

The Lee Valley tool steel experiment as presented to us was a nice bit of testing, but of course not objective science. The presentation is skewed to sell as much expensive PMV11 as possible. It is not openly presenting the results in such a way that it can be verified by other researchers. It's also not objective because they have a commercial interest.

 

[Jacob]

..... there is nothing new to investigate.

Oh come on, Jacob! The fact that people were posing questions above that we couldn't give full answers to disproves that one!

Science is a very long way indeed from knowing everything.

Which of the questions raised above would you investigate if you had the time and money, and why?
Without trailing back through the thread I don't recall anything worth looking at too closely, just a lot of vague ideas and distinctly steampunk dialogue.
The point is - most planes work really well if they are set up well and sharpened by whatever method, whatever the steel (within reason).