Blade gap and exposure

[Flanders]

You beat me to mentioning it, also Henson aggressive and Timeless .95. This is already starting to show a clear correlation between the measurements and the type of adjustment. I am wondering though about those three on the far right, that seems a bit strange.

One other thing, it has been mentioned before, but many of these razor designs targeted traditional Gillette gap measurements specifically so eventually that should show up. Have a look at the chart at ATT:

Blade Gap Comparison

.001 inch millimeters Razor weight in grams 4 0.10 Above the Tie (ATT) G1 (v.1) Atlas = 94g / Kronos = 105g / Colossus = 120g / Bamboo = 90g 8 0.20 Rockwell R1 100g 10 0.25 Above the Tie (ATT) M1 & M2 Atlas = 94g / Bamboo = 94g / Calypso = 112g / Kronos = 109g 10 0.25 Above the Tie (ATT) SSM1 &...

www.abovethetie.com

Obviously, it doesn't have exposure which has always been elusive.

 

[Patrice]

I'm happy there's another nerd in the place.
The measures on the right come from those posts.
I thought the ATT table was coming from here or maybe it's the opposite...

+ I really think I calculated it wrong with the Progress based on those pictures.
Could you do the math on your end and tell me what you think?

 

[Flanders]

+ I really think I calculated it wrong with the Progress based on those pictures.
Could you do the math on your end and tell me what you think?

I haven't been able to measure pictures for awhile, I need to figure out what happened to my software. Just looking at the graph, it doesn't seem right. Most people describe a significant jump in blade exposure, it should at least follow the same line as the other adjustables. I wouldn't be surprised if it tops out around .15mm, I think I have heard estimates around that! If I am not mistaken, that is the razor that flattens the blade curve as you dial up looking at the GIF.

 

[Patrice]

.15 would make more sense indeed
updated! wolfman added

 

[Flanders]

If we want to get into the speculative realm, apparently we do, you could knock .03mm off all of the Karve exposure numbers as it's been shown numerous times that the C plate is actually neutral exposure and there is at least one photo that measured the D plate at .10mm. He questioned what blade was in there, but I have little doubt that it was a standard blade based on experiences with the C plate. We had some discussion almost two years ago about how these published numbers could be so far off, but consistently off(not random). It's probably something to do with the as designed product and how much the milling and finishing actually take off not being accounted for. The blade width is the reason that the older published Blackbird number is off, his standard blade is narrower than than most others. Experience also agrees with this.

 

[Patrice]

Do you think this is better?

 

[Frito Ray]

Just curious, since very few razors perfectly align the blades, to get the blade exposure figure, do you take measurements on both sides and average them out?

 

[Flanders]

Just curious, since very few razors perfectly align the blades, to get the blade exposure figure, do you take measurements on both sides and average them out?

That is a really good question. I know in one of the older threads that the person who started it was checking both sides, but decided they actually were close enough. We were measuring based on the known thickness of a razor blade. Otherwise, you are dealing with whether the manufacturer actually tests, Henson, or relies on their CAD files.

 

[Frito Ray]

The thought occurred to me because with my Fatip, I often end up with one side noticeably milder than the other. it’s like having two razors in one… do the first pass with the agressive side and second with the mild. Works out well in the end.

 

[Flanders]

The thought occurred to me because with my Fatip, I often end up with one side noticeably milder than the other. it’s like having two razors in one… do the first pass with the agressive side and second with the mild. Works out well in the end.

I know exactly what you mean and find that annoying. I don't think it's that hard to manufacture a cap with the blade centred as all they have to do is centre the post and receiving end, that would be a setup issue if that makes sense. The problem with the Fatips and few others is the posts aren't wide enough when this width has been standardised for decades. With modern manufacturing, I think the precision hangs on the blade as we have seen batches with one side ground different than the other and that got past QC.

 

[nlife]

This thread is breaking my brain! I'm going to have to come back and read it a few times, but I think I get it. I really appreciate the effort that people are putting into the discussion.

 

[AndyPanda]

I know exactly what you mean and find that annoying. I don't think it's that hard to manufacture a cap with the blade centred as all they have to do is centre the post and receiving end, that would be a setup issue if that makes sense. The problem with the Fatips and few others is the posts aren't wide enough when this width has been standardised for decades.

This is what I do with my Fatip - now the cap and blade center perfectly every time without any fussing about. I take a little heat shrink tubing (I pick a size that is a bit too narrow to fit over the alignment posts without stretching it first) and cut a thin circle so it just barely reaches into the base plate alignment holes when tightened down. The shrink sleeve doesn't go all the way thru the baseplate, just barely squeezes into the very top of the hole and centers the cap on the base.

When you clamp down the blade, it curves up and over the shrink sleeve tubing and centers itself. Works like a charm for me. I put the little rings over the tip of needle nose pliers and open the jaws to stretch the ring a little and then slip it over the alignment pins quickly before it shrinks back down. It's tight enough to stay in place but you can pull it off with your fingernails if you don't like it.

I do the same with my Merkur 37C and get perfect blade alignment every time

 

[Patrice]

Hi everyone
Update, Yates added

 

[JCarr]

Hiya!

Gillette Tech: 1957 Gillette Tech: Review, Photos, Measurements, Photo Analysis - https://www.badgerandblade.com/forum/threads/1957-gillette-tech-review-photos-measurements-photo-analysis.545851/
Blackbird: https://www.kickstarter.com/projects/blackland/the-blackbird-stainless-steel-safety-razor-0

Interesting comment which shows that gap and exposure don't do it all

Thanks for the Blackland Kickstarter link. Very interesting. Only a .58 gap and it's a very efficient razor.

 

[Patrice]

Hi JCarr,

We have finally modified the blade exposure a bit in order to be closure to what people experience on a regular basis.
Blade gap is indeed not a specification related to efficiency (0.14 VS 0.101).

Extract of the wiki from @ShavingByTheNumbers: "Blade gap is commonly associated with razor aggressiveness, but, at best, blade gap only loosely relates to razor performance. Blade exposure, guard span, and blade angle, on the other hand, are very important performance parameters with respect to aggressiveness (the ability to cut and irritate skin) and efficiency (the ability to cut hair close to skin)."

Adjustable razors de facto modify gap and exposure proportionally, razor makers have followed that logic until Atelier Durdan with Le Maurice therefore people associate gap with efficiency but it's an error.

Small gap and reasonable exposure makes a razor soft and efficient, that's the BlackBird!

 

[BigJ]

Welcome aboard!

Interesting discussion!!

For me, there is no single determinant of ‘aggressive’ razor design. The calculus is complex.

 

[Patrice]

Absolutely BigJ, this graph is a nerd amusement and there are tons of other parameters which make every razor unique and a piece of art.
I thought that blade gap is too much put upfront and that it was interesting to combine it with exposure.
I'm very happy with the result, I find it very enlightening - for what it's worth.

A reminder of the url of the wiki from @ShavingByTheNumbers (I hope he will see this thread at some point!)

Safety Razor Parameters: Illustrated and Defined

...

www.badgerandblade.com

 

[T Bone]

I've been reading along with interest, @Patrice. Thanks for posting this. You can add the aggressive to the Henson (gap 0,99 mm, exposure 0,115 mm), I saw your link to your sheet but I don't want to screw up your work.

 

[Patrice]

Thanks @T Bone!
The file is read only I hope
Will do!

 

[Patrice]

Aggressive version of Henson integrated, thanks again for spoting it @T Bone