Tatara Noda-mune and Masa-dachi have positive exposure

[spacemonkey42]

I just did a cardstock test with my Tatara razors - running the razor along the edge of a piece of cardstock, if the blade bites into the paper, the exposure is positive.

The Tatara Nodachi top cap with Masamune base plate (Noda-mune) is supposed to be neutral. With a Perma-Sharp it is clearly positive, biting into the paper and slicing off a strip of paper. Guessing, I think it would be around a half a mm or so.

The Masamune top cap with Nodachi base plate (Masa-dachi) is supposed to be negative. With the same Perma-Sharp it is also just a hair positive, as it bites into the paper. It does more than just rough up the edge. So it is not negative.

Have others tried this test? What did you find? I was surprised, but that explains why the Noda-mune is much more efficient than I expected. @TATARA RAZORS, do you have any thoughts on this?

 

[WetShaveVet]

Thank you. Goof info.

 

[spacemonkey42]

Of course, as all manufacturers say: exposure is blade dependent as blade dimensions may differ.

And having a positive exposure is not a bad thing. I was just wondering how it could be so efficient with a neutral or negative exposure.

 

[Flanders]

Yeah, it's probably positive in the same way that the Game Changers are: so slight that the manufacturer doesn't even want to say how much. But in this case, they do and it's wrong. It feels like 0.02-0.03mm to me and I have tested it with card stock in the past. Off to check the width of Feather blades compared to Gillette PPI blades...

Hmm, a Feather is 22.03. That's the wrong direction, 0.04 wider per side.

 

[cakaguna]

It’s been a while since I had the tatara razor, but I noticed the same thing with the nodachi cap and the masamune plate, same sort of test with card stock.

 

[spacemonkey42]

I guess, I am not crazy... This time at least. Don't get me wrong, I like this razor, I just couldn't understand how it was so efficient.

@Flanders, I think that's about right, I'd guess a little less than half a mm, 0.03mm could be it. But it is certainly positive.

 

[Flanders]

Something just occurred to me...

I wonder if the designed parameters are only valid for the standard configurations and the others are calculated approximations?

What I am thinking is that swapping the cap probably doesn't have the same effect across all combinations, the plates would be more precise though.

So maybe the Masamune and the Nodachi are correct and everything else between there is slightly different than listed? Of course, I could also see the Nodachi as having more exposure than listed as well... so maybe my theory is wrong.

 

[spacemonkey42]

Since they are making them with precision CNC, even the combos should be at least consistent. They should be able to measure them once and that would be accurate. Maybe they just used a more narrow blade.

 

[Galibier_Numero_Un]

Yup, I was surprised that the Masa-dachi combo felt about as aggressive as the Athena did to me, which is to say just the slightest bit too spicy in comparison with my Overlander.

I'd have to check my log to see which blades I used. At the time, my Personna PCs and Wizamets were in heavy rotation, along with the occasional GSB.

I didn't do the card stock test (which would have been instructive). Instead, I did the face test which told me everything I thought needed to know

... Thom

 

[AndyPanda]

Same here. I've noticed that about several razors that claim neutral or negative. Note that when tightening the handle on the Masamune (at least on my dark Masamune), because of the way the handle fits thru the hole in the baseplate, it gets tight feeling and can still turn another 1/8-1/4 turn depending on just how hard you dare twist the handle. I can definitely feel the difference on my face between "normal tight" "good and tight" and "really tight"

 

[cakaguna]

Since they are making them with precision CNC, even the combos should be at least consistent. They should be able to measure them once and that would be accurate. Maybe they just used a more narrow blade.

They come new with feather blades, so I’m guessing that is what they used for measurements

 

[Galibier_Numero_Un]

Same here. I've noticed that about several razors that claim neutral or negative. Note that when tightening the handle on the Masamune (at least on my dark Masamune), because of the way the handle fits thru the hole in the baseplate, it gets tight feeling and can still turn another 1/8-1/4 turn depending on just how hard you dare twist the handle. I can definitely feel the difference on my face between "normal tight" "good and tight" and "really tight"

This comment had me scratching my head, so I went to my (clear) Masamune. Apart from paying attention to feeding the handle through the thru-hole in the base plate, there's no perceptual difference between tightening my Overlander and my Masamune.

From the point where I feel the cap begin to flex the blade to good and tight (without being a gorilla about it), it's about 1/4 of a turn.

As a reality check, I loaded the same Wizmamet blade into my stainless Overlander and the same results were achieved with slightly less than 1/4 of a turn (3/16? 7/32?).

The only reason I'm writing this is so people don't go about stripping any threads. As a mentor of mine once stated: "the next step after really tight is really loose"

... Thom

 

[Slapo]

Since they are making them with precision CNC, even the combos should be at least consistent. They should be able to measure them once and that would be accurate. Maybe they just used a more narrow blade.

Perhaps finding out what blade they used would be the best first step, if they used an actual blade and not just math based on assumed/averaged blade dimensons.
Otherwise, it'll be an infinite guessing game.

Perhaps it would be worth finding out how much tool wear affects tolerances. Ideally, it wouldn't, but it likely does slightly in real life.

 

[Iridian]

The only reason I'm writing this is so people don't go about stripping any threads. As a mentor of mine once stated: "the next step after really tight is really loose"

This saying exists also in German, "nach fest kommt ab" (after "tight" comes loose/"off") and I irritationgly get accused of that when screwing pickle jars tight. Yes, I am THAT guy who does that.

 

[Slapo]

This saying exists also in German, "nach fest kommt ab" (after "tight" comes loose/"off") and I irritationgly get accused of that when screwing pickle jars tight. Yes, I am THAT guy who does that.

Bit of a pickle, innit? ;-)

 

[AndyPanda]

I would hope that nobody is going to read my post and then get out vice grips and strip their threads. I sometimes forget that not everyone has had as much experience with mechanical things.

I don't experience the same thing with my newer, stainless finish Nodachi. The Nodachi tightens just like any other razor. But I have two very early (numbered) Masamune Dark razors and the fit where the sleeve-tip of the handle goes into the plate is very tight tolerances. I suspect, but don't know for sure, that Tatara may have loosened some of their tolerances on later razors. I know there are a few brands of blades that need a little coaxing to fit. Feathers fit perfectly and I've read posts where users asked about "crunch" sounds when tightening down their Tatara - and I was guessing they were hearing the blade crunch because they didn't coax their blade over the post and tabs first.

My tight tolerance, serial numbered, Dark Masamune razors (I have two of them) both feel snugged up before they get to the stop. I asked Tatara about it (years ago) and they explained it was the close tolerances and that I should continue tightening all the way. I'm sure I exaggerated when I said 1/8-1/4 turn -- and this crude drawing is exaggerated as well -- but trying to illustrate in a way that you can see what I mean. It isn't fully tightened until it gets to the stop.

 

[uptown]

Loosening the handle to get more blade feel (exposure) is nothing new. I read this years ago on a defunct forum. Phoenix Shaving's Ascension Twist razors use this feature to make it an adjustable razor. However, when you loosen their razors only the blade creates more expose as the top and bottom plates do not feel loose. A little trickery but it works.

 

[spacemonkey42]

Another interesting observation - a cardstock test seems to say the full Masumune is quite close to neutral. It seems like the blade just nibbles at the cardstock. I'd love it if others would test too and report back.

I am wondering how this could be, but that's what I saw when I tried it. It could be that it is neutral when the card in in a scallop of the baseplate. I couldn't keep the card on the peak of a scallop to be sure.

Yes, the razor is fully screwed together and the baseplate is firmly pinching the blade to the top cap. I'm using a Perma-Sharp, if that matters for width.

 

[Galibier_Numero_Un]

I would hope that nobody is going to read my post and then get out vice grips and strip their threads. I sometimes forget that not everyone has had as much experience with mechanical things.

I don't experience the same thing with my newer, stainless finish Nodachi. The Nodachi tightens just like any other razor. But I have two very early (numbered) Masamune Dark razors and the fit where the sleeve-tip of the handle goes into the plate is very tight tolerances. I suspect, but don't know for sure, that Tatara may have loosened some of their tolerances on later razors. I know there are a few brands of blades that need a little coaxing to fit. Feathers fit perfectly and I've read posts where users asked about "crunch" sounds when tightening down their Tatara - and I was guessing they were hearing the blade crunch because they didn't coax their blade over the post and tabs first.

My tight tolerance, serial numbered, Dark Masamune razors (I have two of them) both feel snugged up before they get to the stop. I asked Tatara about it (years ago) and they explained it was the close tolerances and that I should continue tightening all the way. I'm sure I exaggerated when I said 1/8-1/4 turn -- and this crude drawing is exaggerated as well -- but trying to illustrate in a way that you can see what I mean. It isn't fully tightened until it gets to the stop.
View attachment 1900882 View attachment 1900894

That's interesting. I can see where a manufacturer might find that they were a bit too "ambitious" with their tolerance specs.

As a side note, I fit my RR Ti Halo handle (Razorock) to my s-s Overlander this evening, and it's a bit sticky at the final bit of tightening (as the butt end of the handle engages more firmly with the base plate) - somewhat as you described. A stainless handle from Maggards doesn't do this. I mention these two handles because they're both M5 threads. The Overlander cap has a 10-32 stud but this combination is compatible.

I've been surprised at the mechanical challenges many males in the US face, which is why I mentioned tightening force in the first place. I have one customer who has to chant "lefty-loosey, righty-tighty" to remember which way to turn a screwdriver. I kid you not. I never heard this child's memory trick before.

Another interesting observation - a cardstock test seems to say the full Masumune is quite close to neutral. It seems like the blade just nibbles at the cardstock. I'd love it if others would test too and report back.

I am wondering how this could be, but that's what I saw when I tried it. It could be that it is neutral when the card in in a scallop of the baseplate. I couldn't keep the card on the peak of a scallop to be sure.

Yes, the razor is fully screwed together and the baseplate is firmly pinching the blade to the top cap. I'm using a Perma-Sharp, if that matters for width.

I never felt comfortable doing the card stock test, in the sense that I don't know how the card will flex. We're talking about -0.13mm exposure on the Masamune which is about .005" after all. Maybe a block of soft wood?

What can I say about the Masamune? It's the slightest (I mean, slightest) bit milder than my Overlander. If the Masamune was an adjustable, I might call it 1/4 click milder which is to say very close.

More to the point (all of you razor designers out there). Hasn't the Athena, the Overlander and experiences with a host of other razors convinced us that with the exception of extreme numbers, the published dimensions don't tell the story? I get why Shane at Blackland ceased publishing them.

... Thom

 

[Iridian]

I just realized I never tested a razor shaving paper or cardboard. I have only the full Nodachi, so cannot test if the Masamune is neutral or even negative.

What I want to say, a paper or cardboard, one has to do this with a light touch but negative should be negative and not leave a mark indeed.