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DE razor geometry. A system for measuring aggressive razors.

That looks like what I was trying to do with my "optical leveler" idea! I can't figure out what it's doing. What's it normally used for? Seeing all the cool tools you have is starting to make me think I need a bigger toy budget. 😃
I normally use my Tele Vue 13mm Nagler Type 6 eyepiece in my telescope, but I am using it here to align the Plugable Microscope by shining the light through and lining up the reflections. You don't want to know how much it cost, trust me. I got it before I got married.

The Tele Vue 13mm Type 6.

This is a pretty interesting article about how Al Nagler helped with the Apollo Missions.
 
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Do you think this coin microscope would work Can any of you poke holes in this product.

Coin Microscope,Elikliv 4.3" LCD Digital Microscope 1000x with 8 LED Lights for Kids and Adults,Handheld USB Microscope Camera for Coin/Soldering,PC View,Windows Compatible
I agree with @APBinNCA, it's probably not the right tool for the job. I'd also be careful of some the one's labeled 5mp. Many of them are really only produce 2mp images, but they do some pixel interpolation on the backend and call it 5mp. I think the key thing we're looking for on any of these inexpensive microscopes is the resolution of the images they produce. This takes some digging in the reviews usually. That rule of thumb changes a bit when you get over $500 and into the world of Dino Lite USB microscopes because the optics and image sensors are so superior, but I don't think any of us are thinking about dropping $1,000 on one of these.

Resolution: The resolution on that microscope is 640x480 vs the Plugable USB 2.0 which has 1600 x 1200. So it's a 0.4mp camera vs a 1.92mp camera. The Plugable USB 2.0 is also about half the price of this one at $32.

Working Distance: If it's made for coins, I'm not sure whether the stand will even accommodate a 42mm tall razor. It looks like it might not be able to.

Stand Rigidity: Microscopes have very shallow depth of field, and the blade is 3mm lower than profile on most modern razors in order to cover the blade tabs. This means having either the profile or the blade somewhat out of focus, or doing focus stacking. Focus stacking requires an extremely rigid stand to ensure absolutely zero camera movement between shots due to refocusing or else you get ghosting, artifacts, and questionable accuracy. No way of knowing if that stand is up to the task.

LCD screen: It adds no value if you've got a laptop or pc, but it probably represents 50% of the cost of the unit

Just my two cents, but I'm no expert on microscopes.
 
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My Lupo .95 Scalloped SB baseplate finally came in! I'm on shave #2 with it and I really like it. Oddly enough, my first impressions of it were that it was just a tiny bit milder than the Lupo .72 Scalloped SB. It's too soon to tell though. Sadly I have only one top cap, so I can't do a side-by-side comparison. :(

I stuck it under the microscope earlier and found that it has nearly neutral exposure vs the Lupo .72 which has an exposure of 0.05mm.



This photo explains why the Lupo .72 has more blade exposure than the Lupo .95. It's a brilliant design update. I haven't measured the Lupo .72 blade angle, but I expect it to slightly higher than 28.5 degrees.



Here are the source photos sans measurements. One is the "A" corner and one is the "D" corner to check for blade skew and account for machining variations.



 
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The Mamba .53 is a frequent contender in "mildest razor" threads. Having measured the Mamba .53 now several times, it boggles my mind that it has triple the exposure of a Lupo .95 and nearly triple the gap of a Muhle R41. 😲

If that doesn't argue the case that neither exposure nor gap determine "aggressiveness", I don't know what does.
 
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My Lupo .95 Scalloped SB baseplate finally came in! I'm on shave #2 with it and I really like it. Oddly enough, my first impressions of it were that it was just a tiny bit milder than the Lupo .72 Scalloped SB. It's too soon to tell though. Sadly I have only one top cap, so I can't do a side-by-side comparison. :(

I stuck it under the microscope earlier and found that it has nearly neutral exposure vs the Lupo .72 which has an exposure of 0.05mm.



This photo explains why the Lupo .72 has more blade exposure than the Lupo .95. It's a brilliant design update. I haven't measured the Lupo .72 blade angle, but I expect it to slightly higher than 28.5 degrees.



Here are the source photos sans measurements. One is the "A" corner and one is the "D" corner to check for blade skew and account for machining variations.



The base plates are a little different in the front part area for sure, your .95 base plate looks a little thicker in the front so that would affect blade exposure. Interesting photo of the two base plates, that's maybe why some folks are saying the Lupo.95 is smoother than the Lupo .72because some of them might have a little less blade exposure. I'm glade you bought a .95 base plate Nick & hopefully you enjoy it.
 
All these measurements.......but there are too many other variable......, it just isn't a mathematical equation. Well it might be for one person to compare between your razors (same soap, technique and beard); but once you throw all the variables.....and then the user applies some more pressure and it all changes again....
 
All these measurements.......but there are too many other variable......, it just isn't a mathematical equation. Well it might be for one person to compare between your razors (same soap, technique and beard); but once you throw all the variables.....and then the user applies some more pressure and it all changes again....
Sounds like you're saying that we're tilting at windmills. Since my avatar is literally a guy getting ready to charge windmills, I won't take offense. :w00t:

People said the same thing about rigidity. Now we have the Rosseforp Rigidometer, which can measure rigidity with precision and repeatability using a pressure gauge and a dial indicator. I think we'll be able to solve the mystery of aggressiveness too.

Consider that I can give 1,000 people a Mamba 0.53 and an R41, and after trying both 999 of them will say the R41 is an order of magnitude more aggressive than the Mamba .53. Can you explain why? Can anybody?

At the end of all this, I think we'll be able to, and I think we'll be able to express it mathematically. If I'm wrong about that, I'll still be happy, because I'm having fun playing with razors and toys. 😃
 
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Chan Eil Whiskers

Fumbling about.
Sounds like you're saying that we're tilting at windmills. Since my avatar is literally a guy getting ready to charge windmills, I won't take offense. :w00t:

People said the same thing about rigidity. Now we have the Rosseforp Rigidometer, which can measure rigidity with precision and repeatability using a pressure gauge and a dial indicator. I think we'll be able to solve the mystery of aggressiveness too.

Consider that I can give 1,000 people a Mamba 0.53 and an R41, and after trying both 999 of them will say the R41 is an order of magnitude more aggressive than the Mamba .53. Can you explain why? Can anybody?

At the end of all this, I think we'll be able to, and I think we'll be able to express it mathematically. If I'm wrong about that, I'll still be happy, because I'm having fun playing with razors and toys. 😃

BOSC.2.Pure Scientific Curiostiy.jpg


I don't understand how razors work, but I think it can be figured out.




Happy shaves,

Jim
 
Sounds like you're saying that we're tilting at windmills. Since my avatar is literally a guy getting ready to charge windmills, I won't take offense. :w00t:

People said the same thing about rigidity. Now we have the Rosseforp Rigidometer, which can measure rigidity with precision and repeatability using a pressure gauge and a dial indicator. I think we'll be able to solve the mystery of aggressiveness too.

Consider that I can give 1,000 people a Mamba 0.53 and an R41, and after trying both 999 of them will say the R41 is an order of magnitude more aggressive than the Mamba .53. Can you explain why? Can anybody?

At the end of all this, I think we'll be able to, and I think we'll be able to express it mathematically. If I'm wrong about that, I'll still be happy, because I'm having fun playing with razors and toys. 😃
I am sure there are mathematical differences. And then throw a Kai instead of a Derby blade and all changes.....
I go by feeling......some feel better some don't.
One thing for sure, lets take the Karve.....there I can tell the difference between the gap in the baseplates.... , I bet it's the same with those with different baseplates.....comparing apples to apples
 
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I am really confused, which one is the "design update?"
Also, you probably should label that picture.
Lupo .95 on the left, Lupo .72 on the right. Lupo .95 is the new one. Joe & co removed material to increase gap and guard span, but raised the height at the edge to raise the shave plane in order to reduce exposure. In the process, the muzzle volume is also reduced making more responsive to pressure. Thats what it looks like to my eye anyhow. I should probably measure it.
 
Thanks for the explanation Nick. If my eyes aren't mistaken, the .95 has a higher blade angle than the .72 a la Henson. It is sighted as one the reasons it feels so mild. With more blade angle, if you put pressure, the blade edge isn't being pushed proportionally equal distance to the pressure applied. It would explain why the .72 reviews are all over the place. One person shaves with no pressure and has no trouble, another applies just slight pressure and get's bit.
Also, I would assume the .95 would have the same 0.05mm exposure as the Henson medium if it was fitted with the ubiquitous Astra SP. That is interesting because it would be a lot more efficient, but the guard design is clearly less safe.
 
it just isn't a mathematical equation.
Recall the vintage Superspeed ad, Gillette ranks aggressiveness based on exposure and weight. Therefore it is reasonable to assume the problem can be formulated and solved with mathematics.
Maybe our refinement is off, maybe we are closer to the truth, maybe this thread will result in a solution worthy of the Nobel prize in physics* - too early to say.

*unlikely, some of the staff of the Swedish Academy of Sciences wear a beard
 
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The Mamba .53 is a frequent contender in "mildest razor" threads. Having measured the Mamba .53 now several times, it boggles my mind that it has triple the exposure of a Lupo .95 and nearly triple the gap of a Muhle R41. 😲

If that doesn't argue the case that neither exposure nor gap determine "aggressiveness", I don't know what does.
Unfortunately I cannot afford the equipment required to make accurate photos and measurements. Neither do I possess the Mamba.
What I can see though, if I compare the Mamba with the R41, the former must offer a very rigid blade, since the free-end distance of the R41 is higher. Also, the R41 is OC-ish, so even less of the blade is actually supported and the skin is not pulled as well as with the SB Mamba. As for the gap, I am still not convinced it makes sense when applied to OC razors, since e.g. for the R41 it would be neccessary to measure several gaps. Let's say one gap between the blade and a tooth, one between the blade and the part of the base plate between 2 teeth and 1 measurement somewhere between the prior 2. Then normalize and you will obtain a much higher "mean blade gap" vs the gap of the Mamba.
If I had to guess, the Mamba would compare in aggressiveness to a Gillette Old Type, a Feather AS-D1 or [email protected]
 

Chan Eil Whiskers

Fumbling about.
I am sure there are mathematical differences. And then throw a Kai instead of a Derby blade and all changes.....
I go by feeling......some feel better some don't.
One thing for sure, lets take the Karve.....there I can tell the difference between the gap in the baseplates.... , I bet it's the same with those with different baseplates.....comparing apples to apples

Most of us including me don't own any Wolfman razors much less a lot of them. I've read that it's known how their gaps increase. The increase and what causes it is easy to see from some photographs taken by Wolfman owners who're into studying the matter. As far as I know it's the only variable change going from one WR2 to another (but I could be wrong). If so, it's another apples to apples comparison.

Happy shaves,

Jim
 
As far as I know it's the only variable change going from one WR2 to another (but I could be wrong). If so, it's another apples to apples comparison.
That would be really interesting to test. Usually, when gap increases, the blade exposure increases as well (Karve, Gillette Adjustables, Game Changers, etc). The Lupo .95 is the first razor that I've seen where the gap is increased, and exposure appears to decrease. Since the Lupo (latin for wolf) is a Wolfman inspired design, it would be fascinating to see if Wolfman was the one who first decreased exposure while increasing gap, or kept exposure constant while increasing gap.

Somehow I think finding Wolfman specimens in the wild might prove more challenging than Game Changers though. 😏
 
As for the gap, I am still not convinced it makes sense when applied to OC razors, since e.g. for the R41 it would be neccessary to measure several gaps. Let's say one gap between the blade and a tooth, one between the blade and the part of the base plate between 2 teeth and 1 measurement somewhere between the prior 2. Then normalize and you will obtain a much higher "mean blade gap" vs the gap of the Mamba.
Interesting. I've never really thought about that. True open comb razors present a particular challenge though, because the gap is effectively infinite between the combs, which makes them hard to average.

I've done one pass shaves with a open comb razors, and my shaving strokes extend as long as possible (sideburn to clavicle) with as little overlap as possible, and no second strokes on unlathered skin. I've never noticed a difference in shave quality, or "stubble stripes". Still though, the gap is clearly different between combs in some razors like you say. 🤔
 

Chan Eil Whiskers

Fumbling about.
That would be really interesting to test. Usually, when gap increases, the blade exposure increases as well (Karve, Gillette Adjustables, Game Changers, etc). The Lupo .95 is the first razor that I've seen where the gap is increased, and exposure appears to decrease. Since the Lupo (latin for wolf) is a Wolfman inspired design, it would be fascinating to see if Wolfman was the one who first decreased exposure while increasing gap, or kept exposure constant while increasing gap.

Somehow I think finding Wolfman specimens in the wild might prove more challenging than Game Changers though. 😏

From what I've read the Wolf's blade exposure increases with the gap (because the gap increases).
 


TLDR: I bought the Apexel Pro Macro 100mm. Distortion is too low to measure in the target area with the grip used for testing. The flip side of that is that the 2.5cm working distance means the target area (blade apex, gap, shave plane) is roughly 500x500 pixels in my test shot. It will necessary to experiment to see how close the lens to increase the pixel count in the target area. Over-all, I think this could be a viable alternative to microscopes with a bit of experimentation. It offers superior focus stacking because adjusting manual focus does not disturb or shift the camera.

Long Version:

I used my google-fu to figure out how to get the manual focus on my ancient Samsung Galaxy S7 working. I also bought an Apexel Pro Macro 100mm from Amazon. Here is the test shot of a grid. It's a massive photo at 2268 x 4032. You'll probably need to do a "save as image" and zoom in with a ImageJ or some other application to see what I'm up to. The yellow lines are straight lines that I've drawn to spot and measure curve caused by the lens. The big red square in the center is the size of the target are of the razor in the photo. There is definitely distortion on the perimeter + but it improves towards the center. Across the 500 x 500 pixel span in the center, there is distortion, but it's too small to measure with this grid. I will need something much finer and more precise to even measure it. In other good news, I think it will be much easier to do focus stacking with a cell phone without moving the camera.



That's the good news. The bad news is that the lens has a very long focal distance, which means the target area (blade apex, gap, and shave plane) is is relatively small in the picture. I knew the focal distance was >2.5cm when I bought it, but the only way I could be sure of how large the "target area" would be in the picture was to buy it and try. In my first test picture, the target area is 500 x 500 pixels. This is lower resolution than I'm achieving with the microscope. That said, the distortion is low, and the camera sensor is much less light hungry. I'm going to have to play with it a bit to see how large I can make the target area. I'm guessing 700 x 700 pixels is achievable.

 
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