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Measuring DE Blade Width with Digital Caliper and Homemade Cardstock Fixture

With this kind of detailed information about both blades and razors, the YMMV acronym might need to be retired.

I think that the YMMV acronym might always be around, and that's okay, but maybe we can diminish its use by providing previously unknown information and analysis that sheds light on the unknowns and ambiguities that lead many to use the acronym in the first place.
 
Here is the cutout dimensions list as I now see it:

Blade Cutout Length --- it's obvious what this is, even without a diagram
Blade Cutout Width --- very important relative to the width of blade alignment bars on razors
Blade Cutout Circle Diameter --- the diameter of the circle part of the cutout
Blade Cutout Diamond Diameter --- the diameter of a circle that fits inside the diamond parts of the cutout
Blade Cutout Diamond Width --- the width of the diamond parts of the cutout; probably identical to keyhole width
Blade Cutout Keyhole Width --- the width of the keyhole parts of the cutout; probably identical to diamond width

What do you think, Cal?
After each night's sleep the blade dimension nomenclature in my head changes. :blink:

Moving along... do you agree that the below are all the dimensions required G (i.e. 10 in total)?
$Blank Blade Dimensions.jpg
 
[MENTION=106012]1Cal[/MENTION] There was a reason I stopped measuring blades as I thought I was getting too technical. You bring a whole new dimension to the technical part of this.

I am just kidding.
 
Cal,

We actually have 11 dimensions now. :lol:

Here is the illustration that I put together in PowerPoint. Please look over it and let me know of any problems or concerns. (Don't mind the quality of the lines and such. That happened when creating the bitmap. I'm sure that I can generate a crisp picture in the future.) I think that we got it this time, but I won't hold my breath. :blink:

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Cal,

I fixed the illustration's quality. The lines are now solid black. Also, I came around to your side on "edge length" versus "cutting edge length", in part because the distinction is good for SE blades, too. I might as well be more technical on it, and if someone wants to use the shorter "edge length" language in his writing, then that's fine, too. At least the illustration will have the full label. Here is the new version:

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That looks great G. :thumbup1:

How's progress with the polycarbonate fixtures you were considering?

Thanks, Cal. I have my Excel spreadsheet updated with columns for the 11 measurements. It doesn't take long to make the measurements. Given the time and resources that it takes to clean a blade and the measuring surfaces of the micrometer and caliper with paper and rubbing alcohol, which takes some time, it's worth taking the extra time to make all of those little measurements for more payoff.

I've ordered a clear sheet of acrylic (Plexiglass) for $4.83 total ($2 plus shipping). Polycarbonate would have been fine, too, but I eventually began leaning towards acrylic for the fixtures. Acrylic is less likely to scratch and apparently doesn't yellow in time like polycarbonate eventually does. Also, a neat thing about acrylic is that you can use a solvent to "weld" the plastic together, with the solvent disappearing in the process, or you can use a more general bonding system that adds an adhesive layer like glue or epoxy do. I've researched the bonding options and I will probably get an acrylic cement that acts as a solvent cement for bonding acrylic, but will also bond polycarbonate and other materials. (I'd like to get an adhesive that doesn't yellow in time.) The sheet of acrylic is stated as having a 0.080" thickness, which means that the true thickness is probably more like 0.072" (1.83 mm), or at least I hope. The caliper jaws are about 3.5 mm thick. The total thickness of the blade plus two inner plastic layers plus adhesive layers (connecting the inner plastic layers to the outer plastic layers) should be greater than 3.5 mm so that the outer plastic layers that go around the caliper jaws have just enough wiggle room. If the space between the outer plastic layers is too large, then I will have to add something to close the gap or maybe even try a thinner plastic sheet and hope that it isn't too thin.
 
[MENTION=111161]ShavingByTheNumbers[/MENTION]

One of my ex-wives description of me would appear to fit you like a glove G: "If a job's worth doing, it's worth overdoing." :lol:
 
@1Cal

At least I don't have RAD... yet. :001_smile I still haven't even touched the EJ Kelvin that I got about a month ago, which proves that I don't have RAD, but I haven't touched it yet because I want to take pictures of it for the record and for photo analysis, so that proves that I got a different kind of problem. :tongue_sm

UPDATE: The acrylic sheet has been shipped, but I haven't ordered adhesive/solvent yet. In the end, it's easier to make fixtures with a simple plastic sheet and bonding agent than to make cardstock laminate fixtures, and the clear plastic fixtures will be stronger and better, so the way that I see it, I'm saving myself trouble and making something that will last, but spending a little money.
 
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Cal,

I just ordered an acrylic cement for $7.08 with free shipping, which makes the total cost of the acrylic sheet and cement $11.91. Good price, I think. They should both arrive in about a week. If all goes well, they will make great fixtures for blade measurements with my digital caliper. Obviously, I will report on the fixtures with photos. Then, data collection begins, one blade at a time, one week at a time, one month at a time, and so on. It will be a long-term project, but it could be greatly accelerated with blades donated by others, as one generous guy here has already offered. Starting off, I'll just measure my own blades, though, and get the blade dimensions table going in the ShaveWiki.
 
Two thing I'm waiting on;

How thick is a Feather?

How thick is a Kai?

TobyC,

I'm sorry for the late reply. My hard drive failed and, with other things getting in the way, I'm just getting back to normal with a new drive and operating system.

I'm not yet doing regular measurements, but I do have some numbers for you. I had already measured the thickness, using my digital micrometer, of one KAI blade as 0.100 mm. Just for you, in order to give you some Feather numbers here, I cleaned and measured the two Feather blades that I had in my bank as 0.102 mm and 0.104 mm. I hope that that satisfies your curiosity at the moment. In time, with regular measurements, I'll accumulate enough data to have means, standard deviations, and min. and max. ranges of blades. That's the goal.
 
TobyC,

I'm sorry for the late reply. My hard drive failed and, with other things getting in the way, I'm just getting back to normal with a new drive and operating system.

I'm not yet doing regular measurements, but I do have some numbers for you. I had already measured the thickness, using my digital micrometer, of one KAI blade as 0.100 mm. Just for you, in order to give you some Feather numbers here, I cleaned and measured the two Feather blades that I had in my bank as 0.102 mm and 0.104 mm. I hope that that satisfies your curiosity at the moment. In time, with regular measurements, I'll accumulate enough data to have means, standard deviations, and min. and max. ranges of blades. That's the goal.

Ah, thank you very much sir!!! That will do just fine! :thumbup:

Sorry to hear about the hard drive, hope you saved data!
 
Ah, thank you very much sir!!! That will do just fine! :thumbup:

Sorry to hear about the hard drive, hope you saved data!

You're welcome, TobyC. Glad to help. :001_smile Thanks for your concern about my data. I used to be good about backing up data, but I got lazy, so when my hard drive failed, it looked like I might have lost my newer files over the past two or three years. Thankfully, I was able to retrieve my files, which appear okay, from my failed drive using the right cables and a Windows 10 machine. It could have been a lot worse. If you're not backing up your data all the time, learn from my mistake and DO IT! :laugh:
 
You're welcome, TobyC. Glad to help. :001_smile Thanks for your concern about my data. I used to be good about backing up data, but I got lazy, so when my hard drive failed, it looked like I might have lost my newer files over the past two or three years. Thankfully, I was able to retrieve my files, which appear okay, from my failed drive using the right cables and a Windows 10 machine. It could have been a lot worse. If you're not backing up your data all the time, learn from my mistake and DO IT! :laugh:


:thumbup1:
 
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