David charlesworth, cambered blade with a back bevel?

[Jacob]

....
Going back to the original question, the camber on a smoother is so slight that you can get all of it in a flat 1/2mm back bevel. .....

If you freehand the back bevel the same as the front bevel (but at a different angle of course) there is absolutely no problem. It's very easy whatever the degree of camber. Honing jigs and ruler tricks just make things harder.

 

[David C]

Reversing some of Jacob's nonsense, gets us nearer to the truth.

The ruler trick makes things significantly easier and better.

David Charlesworth

 

[Jacob]

Yebbut how to do "the ruler trick" with a cambered blade? Impossible unless you have virtually no camber, as Matthew describes. Easy freehand without the ruler, straight or cambered, and has been done that way since time immoral.

 

[Trafalgar]

If one has determined that their access pathway to higher effective angle planing will be done via back bevels there is no real reason these can't be done freehand on a cutter with no camber or as much camber as one's judgment determines is necessary for the job. The size and 'growth' of the back bevel can be managed by simply honing the back flat every now and then and then sprucing up the BB afterwards.

Otherwise, if the assertion is that the effectiveness of these things lives or dies on controlling the last half-angstrom of metal removal (whether this is easily done with a ruler or not) then maybe there's a better solution overall.

I've used a back bevel. The gates of heaven didn't open up for me. The results were OK, but nothing to write to Mom about. Anybody out there similarly situated or has it become politically incorrect to admit it?

 

[Paul Chapman]

The results were OK, but nothing to write to Mom about.

Well, at least your mother was spared this never-ending diatribe. Pity we can't be.........

Cheers :wink:

Paul

 

[pedder]

I strongly suspect that other darker forces were afoot.

I think the forces have been darker. Even schwarz.

:lol:

 

[woodbrains]

Hello,

Cambering a back bevel on a smoother is unnecessary. Many smoothing plane irons are too cambered anyway. Keeping the back bevel flat helps reduce/control the camber to something more useful. Smoothing plane shavings are, by nature, the thinnest of any of our planes. Too much camber reduces the cutter's width too much, so should be almost imperceptible, so only preventing track marks, with as wide a cut ar possible.

Mike.

 

[ali27]

I think the point I started this thread with is valid. If you have a camber and you have a back bevel,
then only using centre pressure whilst honing the back alters the geometry. How much depends
on how much the radius of the camber is and how big the back bevel is.

DC comments that the camber is very small, so there is no problem, but is that still true when you sharpen
the back at 25 degrees?

DC is having very good results, so it works very well. Maybe it would work even better if he created
a small camber at the back as well. Perhaps it would only give 1 percent more performance which
isn't worth it.

Ali

 

[Trafalgar]

David is right, the camber should be small on your smoother in most instances and shouldn't be a big deal at all if you freehand your back bevel.

A *relatively* heavily cambered smoother implies something other than finishing passes in my view. There are no absolutes of course.

 

[Trafalgar]

The results were OK, but nothing to write to Mom about.

Well, at least your mother was spared this never-ending diatribe. Pity we can't be.........

Cheers :wink:

Paul

'Tis isn't it?

I remain perplexed as to why so many appear to have developed an allergy to high-pitched smoothing planes. Thank goodness for Norris this wasn't always the case.

 

[woodbrains]

The results were OK, but nothing to write to Mom about.

Well, at least your mother was spared this never-ending diatribe. Pity we can't be.........

Cheers :wink:

Paul

'Tis isn't it?

I remain perplexed as to why so many appear to have developed an allergy to high-pitched smoothing planes. Thank goodness for Norris this wasn't always the case.

Hello,

I don't think it is an allergy as such, just a lack of availability. Norris planes etc, are rare and expensive and only LN have really produced a viable substitute. Back bevels are a way of inexpensively emulating high EP planes without actually having one. I suspect if we could get hold of them more readily, they would be more popular. At some point, I might splash out on a middle pitch LN smoother, but until then, I will play with back bevels, cap iron effects and scrapers!

Mike.

 

[Corneel]

How about bevel up planes? I thought they were the chosen ones nowadays for high angle planing. And not too expensive.

And Norisses usually came with a 47.5 degree angle. Not really much different from 45.

 

[Phil Pascoe]

Just like Jacob, I remember time immoral.

 

[Jacob]

...
A *relatively* heavily cambered smoother implies something other than finishing passes in my view. There are no absolutes of course.

An interesting experiment is to shine a bright torch over the surface of an old piece of woodwork. This can show up the plane or scraper marks (if not sanded or worn down by years of use). Often much more distinct than you'd expect. Then compare the backs of the same piece.

 

[woodbrains]

How about bevel up planes? I thought they were the chosen ones nowadays for high angle planing. And not too expensive.

And Norisses usually came with a 47.5 degree angle. Not really much different from 45.

Hello,

BU Planes are another solution, though LV ones are in the same pric as LN high angle frog planes. Norris planes at their best had microscopic mouthes to work in conjunction with the slightly higher angle. Very ornery stuff might not be totally tamed, but almost everything else would.

Regarding plane scallops on old woodwork. Unless modern woodworkers want to parody old hand work, smoothers should be cambered only very slightly. A 2 inch blade taking a fine shaving only needs a hair of a camber, or else only half of the blade actually gets used. There is a lot of good tool steel at the cutters edge that will never see any use, throughout the life of the blade, if cambered too much, not to mention inefficiency in planing each stroke.

Mike.

 

[Trafalgar]

Hello,

I don't think it is an allergy as such, just a lack of availability. Norris planes etc, are rare and expensive and only LN have really produced a viable substitute. Back bevels are a way of inexpensively emulating high EP planes without actually having one. I suspect if we could get hold of them more readily, they would be more popular. At some point, I might splash out on a middle pitch LN smoother, but until then, I will play with back bevels, cap iron effects and scrapers!

Mike.[/quote]

Good points all. Don't forget ECE Primus smoothers are bedded at 50* and have a very easily adjustable mouth.

 

[Trafalgar]

...
A *relatively* heavily cambered smoother implies something other than finishing passes in my view. There are no absolutes of course.

An interesting experiment is to shine a bright torch over the surface of an old piece of woodwork. This can show up the plane or scraper marks (if not sanded or worn down by years of use). Often much more distinct than you'd expect. Then compare the backs of the same piece.

I paused for a moment and then realized that a 'torch' is called a flashlight over here...

I agree with your observations, we see the same thing over here on a lot of pieces.

 

[Corneel]

A very tight mouth is the least effective measure against tearout. It needs to be on the range of 0.1 to 0.2 mm with absoutely no wear concavity in front of the mouth. Most Norris planes had wider mouths then that. But all of them had a capiron.

 

[bugbear]

A very tight mouth is the least effective measure against tearout. It needs to be on the range of 0.1 to 0.2 mm with absoutely no wear concavity in front of the mouth. Most Norris planes had wider mouths then that. But all of them had a capiron.

... and great bedding, and thick blades...

BugBear

 

[Corneel]

Sure, but that doesn't help to prevent tearout.