bearfacedkiller wrote:What about the fact that most of my Golden knives come at around 30 degrees and my Taichung knives come at 40 degrees (or sometimes more). I have had Japanese knives come in at well below 30 and above 40. I absolutely love the idea of this thread though. I am not trying to shoot the idea down but it would also be amazing if the edge angle was included too. I realize though that that is asking for a lot.
It shouldn't matter if we're comparing models directly with each other. I don't think the goal here is to find the best slicer or thinnest, it's just to have an idea what each model comes in at. Unless they start making Taichung models in Japan then the angle of the bevel won't change for a given model, and by averaging numbers we can account for human error and manufacturing tolerances.
It just seems like comparing a Mantra at 40 degrees to a Delica at 30 degrees isn't telling me as much as if all the knives in the test were at the same angle. While it isn't a huge difference the Mantra will measure out thicker with steeper angle. I have long been frustrated by the obtuse bevels on Taichung folders for this reason. They look like they are ground crazy thin and then you find out it was over 40 degrees and then when you put a 30 on it it looks more like a standard bevel. This is just the nature of flat grinds. When I first saw my S110V mule I thought it was super thin but it was just a (I'm guessing) 45 degree bevel. I put a 30 on it and it looked like all the rest. While it is a subtle change, changing the bevel angle does widen the bevel. This is more of an issue with flat grinds than hollow grinds and is a non issue with true scandi grinds. It is just geometry. Maybe I am just overthinking how much effect it actually has on the measurement?
Again, I really love this idea but I just want the data to make as much sense as possible and be as useful as possible.
-Darby
sal wrote:Knife afi's are pretty far out, steel junky's more so, but "edge junky's" are just nuts. :p
SpyderEdgeForever wrote:
Also, do you think a kangaroo would eat a bowl of spagetti with sauce if someone offered it to them?
Darby you're on point with that, it would be great if that were possible but then you introduce each person's sharpening techniques and the fact that reprofiling at all is going to bring you higher up into the blade so even if you did lower the bevel angle you may end up thicker behind the edge because of it. I think it may be helpful to note the angle of the bevel of each model, as you mentioned before, especially since in the past that has fluctuated a bit, but then we also need a reliable way of measuring bevels and that's a whole other topic. These numbers will be less useful comparing one model to the next and more useful just as a reference for each individual model, and then you take into account where it's made and how the bevel angle is.
I thought about adding the approximate bevel angle but I would just be eyeballing it. I've looked at and enough edges and sharpened enough at 20° that I could probably call it an educated guess but it would still be a guess.
Here are some observations....
The Taichung knives all appear to be near 20 dps. Some might be a little more as the bevel appears to be very short. Some I know are a little less. I've sharpened my Sage 1 & 2 on my old Sharpmaker 203MF which only has the 20° slots for the rods. When I sharpened them I used a Sharpie on the bevels and only 2/3 of the ink was removed. I just looked at them with a 10X loupe and confirmed. My Sage 3 & 5 appear to be about the same as the 1 & 2. The bevel on my Mantra appears to be more obtuse than the Sages as the bevel is tiny. I've touched up the Mantra on the SM and, looking at it with the loupe, the new scratch pattern only goes 1/2 way up the bevel. Go figure.
The Golden models all appear to be closer to 15 dps. In some cases maybe even less. All my Golden mfg knives have thicker blade stock than the others so I thought maybe that was the difference I was seeing. However, I've added a 20 dps micro-bevel to some (PM2 DLC, N5 G10, & both M2 BD1 LW's) and the new scratch pattern is very short compared to the rest of the bevel. So the factory bevel on those were considerably less than 20 dps.
The bevels on the Japanese knives also appear to be closer to 15 dps and, again, in some cases maybe even less. Judging by the 20° micro-bevels I've added I know the Delicas, Dragonflies, Manbugs, and Stretches are considerably less than 20 dps.
Of all the things I've lost I miss my mind the most!
If we ignore the curvature of the bevel (if any induced by free hand), measuring the bevel length (from shoulder to apex) and BET will help determining sharpening angle (assuming quite symmetrical sharpening, not like recent Cru-Wear that David did).
BET/2 divided by bevel length is sine of the dps.
Last edited by anagarika on Mon May 01, 2017 9:51 am, edited 1 time in total.
@Sharp Guy: Can you post a shot of where you are measuring spine and blade stock thickness? I'll add some digical measurements to the database accordingly.
adamlau wrote:@Sharp Guy: Can you post a shot of where you are measuring spine and blade stock thickness? I'll add some digical measurements to the database accordingly.
Hi adamlau,
Please see the description in my post on the previous page. Let me know if it's not clear.
I almost bought a caliper for this thread but then I realized all my knives except for 2 backups are reprofiled so my numbers would be wider than most.
It is easy to see why I like regrinds so much after seeing the factory thickness behind the edge. I have had a few ZDP folders reground to .010" and .015" behind the edge. Those things would cut even when the edge wasn't sharp anymore. I love a good regrind. :)
"I'm calling YOU ugly, I could push your face in some dough and make gorilla cookies." -Fred Sanford
Lowering the angle of the sharpening bevel will increase thickness at the shoulders of a FFG blade, because it pushes them up the primary grind. This is least true on a hollow grind, where TBE could even go down a little as you move up the grind.
Bill1170 wrote:Lowering the angle of the sharpening bevel will increase thickness at the shoulders of a FFG blade, because it pushes them up the primary grind. This is least true on a hollow grind, where TBE could even go down a little as you move up the grind.
I don't see how this would matter. It is still thinner than it was before.
"I'm calling YOU ugly, I could push your face in some dough and make gorilla cookies." -Fred Sanford
You make the edge thinner in the spot that the factory bevel shoulder used to be but the new shoulder ends up higher in the blade and so it's thicker. This is why the idea of this thread really only makes sense to measure factory bevels and then then I'm sure there's a good amount of variables especially back when bevels were ground by hand. Adding the measurements of a reprofiled knife doesn't make any more sense than doing the same with a reground knife.
Sharp Guy wrote:I have a micrometer and a dial caliper along with a bunch of knives that still have factory bevel (many with a microbevel added). Where would you like me to measure? With my Mantra, when I measure down near the ricasso I get .0175-.018. When I measure out closer to the tip I'm getting .021 .020. I'm thinking that, due to blade shape, closer to the ricasso would be better. Regardless of where you'd like me to measure I think it would be best to be consistent.
Mantra: .0175-.0180. Spine at ricasso: .118
Hey SG did you measure the Domino ? It seems to be quite thin behind the edge ...
* Reprofiled at approx. 13° per side. Sliverax has been reprofiled once. UKPK S110V has been reprofiled 2 times. Manix 2 LW has been reprofiled at least 3 times.
A couple notes: I was surprised at the BTE measurement for the Positron. Edge bevel appears to be approx. 15° per side. I was also surprised by the BTE measurement of the Delica Pakkawood compared to my FRN Delicas. But after comparing them the FRN knives have a much higher edge bevel. So it appears the edge on the Delica Pakkawood is much more obtuse than the FRN knives. I know it's less than 20° p.s. based on the micro-bevel it had after touching it up on the Sharpmaker. The edge bevel on the FRN Delicas are pretty close to 30° p.s. based on how they compare (visually) to another Delica I have that I've reprofiled at 15°.
Of all the things I've lost I miss my mind the most!
Hey SG you are doing a great job. I am glad you confirmed the fact that my beloved K390 Urban is very thin bte. Now I’m considering a baby Horn sprint. I love very thin bte blades. Keep up the great job. I am very curious about the Domino.
Last edited by elena86 on Sat Jun 16, 2018 2:21 am, edited 1 time in total.
Marius
" A mind all logic is like a knife all blade. It makes the hand bleed that uses it "
( Rabindranath Tagore ) Proud member of the old school spyderedge nation
