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Charcoal Goods - Is it a "rigid blade" design?

Esox

I didnt know
Staff member
I actually just took a pic of my Single Ring.

The blade flex I've been referring too is virtually impossible with these designs. The blades edge is essentially, given an unbent base haha, riding the teeth of the comb.

IMG_2659.JPG


Not so with the the Fatip that has more blade exposure, given the shape of the comb.

IMG_2182.JPG


That tiny bit of blade gap between the very edge and the comb I can feel, quite easily, when shaving with a steep angle.

This is why I find my Single Ring smoother than my Grande. Less blade exposure, making the blade edge even more rigid.


Of course. But to repeat myself it's cap span increase which reduces rigidity not exposure.The position of the edge vis a vis shaving plane has nothing to do with rigidity.

I'm not sure how a wider cap would decrease rigidity. I would think it would enhance rigidity if anything, assuming, its imparting more curve to the blade as cap width increases.

Look at these two razors and how, and where, the base plate supports the blade.

Blackland Blackbird.jpg WolfmanWR1.png

One has a base plate whos support ends well shy of the cap. The other supports, and firmly clamps the blade from both the top and bottom very close to the edge with equal pressure.

How can the one with the lesser base plate support even approach the rigidity of the other. It cant, unless it goes against the laws of physics.

Which is the smoother more effective shaver. Only the person holding it can say, but I know which would work better for me.

As a philosophy major who can barely change a light bulb, I'm fascinated by all this physics- and engineering-speak.

Thats it exactly, physics.

For every action theres an equal and opposite reaction. It could be, and mostly likely is, that only a few of us can actually feel that reaction, but its there all the same.
 
I actually just took a pic of my Single Ring.

The blade flex I've been referring too is virtually impossible with these designs. The blades edge is essentially, given an unbent base haha, riding the teeth of the comb.

View attachment 885060

Not so with the the Fatip that has more blade exposure, given the shape of the comb.

View attachment 885063

That tiny bit of blade gap between the very edge and the comb I can feel, quite easily, when shaving with a steep angle.

This is why I find my Single Ring smoother than my Grande. Less blade exposure, making the blade edge even more rigid.




I'm not sure how a wider cap would decrease rigidity. I would think it would enhance rigidity if anything, assuming, its imparting more curve to the blade as cap width increases.

Look at these two razors and how, and where, the base plate supports the blade.

View attachment 885061 View attachment 885062

One has a base plate whos support ends well shy of the cap. The other supports, and firmly clamps the blade from both the top and bottom very close to the edge with equal pressure.

How can the one with the lesser base plate support even approach the rigidity of the other. It cant, unless it goes against the laws of physics.

Which is the smoother more effective shaver. Only the person holding it can say, but I know which would work better for me.



Thats it exactly, physics.

For every action theres an equal and opposite reaction. It could be, and mostly likely is, that only a few of us can actually feel that reaction, but its there all the same.
Me thinks we're talking past each other. Yes, a wider cap increases rigidity in the Fatip, that was my point. That exposure is decreased thereby is a byproduct of the change in cap span.

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Esox

I didnt know
Staff member
Me thinks we're talking past each other. Yes, a wider cap increases rigidity in the Fatip, that was my point.

Yes, because it lessens blade exposure, making the edge more rigid. The same way my Single Ring does compared to my Grande.

If my Grande had say a .010" wider cap, the blade exposure would decrease again, and I'd bet I'd feel less blade flex at a steeper angle because of it.
 
Yes, because it lessens blade exposure, making the edge more rigid. The same way my Single Ring does compared to my Grande.

If my Grande had say a .010" wider cap, the blade exposure would decrease again, and I'd bet I'd feel less blade flex at a steeper angle because of it.
We do disagree then. What makes sense to me is that the lesser cap span itself is the source of the rigidity, not the reduction in exposure (which, by definition, could be achieved just as:well by a change in the guard position without a change in rigidity).

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Esox

I didnt know
Staff member
We do disagree then. What makes sense to me is that the lesser cap span itself is the source of the rigidity, not the reduction in exposure (which could be achieved just as:well by a change in the guard position without a change in rigidity).

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I guess we do. I'm not sure how a narrower cap, given the same blade exposure, could increase rigidity.

So you're suggesting that if my Fatip Grande had a narrower cap, the rigidity of the edge would increase?
 
I guess we do. I'm not sure how a narrower cap, given the same blade exposure, could increase rigidity.

So you're suggesting that if my Fatip Grande had a narrower cap, the rigidity of the edge would increase?

You've again got it backwards. I'm talking width not length right? All else being equal, Narrower cap (ie 17mm Fatip mk1 vs 19mm Fatip mk2 or whatever) --> greater cap span --> less rigidity, ie greater tendency of the more exposed blade to flex with upward pressure against the cap. It's exactly what you earlier diagrammed in relation to the bottom plate except we are now talking about flex in the other direction.

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Esox

I didnt know
Staff member
You've again got it backwards. All else being equal, Narrower cap (ie 17mm vs 19mm or whatever) --> greater cap span --> less rigidity, ie greater tendency of the more exposed blade to flex with upward pressure against the cap. It's exactly what you earlier diagrammed in relation to the bottom plate except we are now talking about flex in the other direction.

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Hey! I thought we were disagreeing? lol

cc91d50317493c69788b4c668061d17f.jpg


I've already said and agreed that a wider cap would enhance rigidity.
 

Esox

I didnt know
Staff member
"because it lessens blade exposure, making the edge more rigid."

No you said the above which is different. I'll accept now that we agree in any case.

It does lessen the blade exposure, and a byproduct of that, is increased rigidity. I used my own Grande as an example, all else remaining the same.

If my Grande had say a .010" wider cap, the blade exposure would decrease again, and I'd bet I'd feel less blade flex at a steeper angle because of it.

A wider cap on my Grande would do two things, lessen the blade exposure, and increase rigidity of the edge. I dont think it possible, in that example, to have one without the other. They work together.
 
I'm enjoying this thread. As a philosophy major who can barely change a light bulb, I'm fascinated by all this physics- and engineering-speak. All I know is that some of my efficient razors have a rigid blade, and some don't. Some have flex, and some don't. I like to think mojo makes all the difference.
Would be fun to listen in on actual engineers addressing actual engineering problems and read their published and replicated results. But the subjective shave den chatter is also fun.
 
You're both wrong. The vital parameter is the clamp distance.
Span and exposure have nothing to do with stiffness.
 
You're both wrong. The vital parameter is the clamp distance.
Span and exposure have nothing to do with stiffness.
I think of my comments re fulcrum location as reflecting clamp distance if I have the definition right.

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Chan Eil Whiskers

Fumbling about.
I posted this before I saw Cal's post. We must be on the same wavelength.

full


Just reminding myself of the definitions and common language. Otherwise I get confused real easily by all this "engineering."

I use "blade exposure" a lot, and I know it has a technical meaning, but sometimes I use it to mean how much blade I can see sticking out. Even with a technically negative blade exposure sometimes there is a lot of visible blade.

Happy shaves,

Jim
 

Esox

I didnt know
Staff member
Span and exposure have nothing to do with stiffness.

If you have 1/4" of blade exposure, that will be less rigid than if you have 1/8" of blade exposure. The closer the blade is clamped to the edge, the more rigid that edge will be.
 
If you have 1/4" of blade exposure, that will be less rigid than if you have 1/8" of blade exposure. The closer the blade is clamped to the edge, the more rigid that edge will be.
Do you mean blade exposure or blade reveal?
 
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