Welcome, Guest
You have to register before you can post on our site.

Username/Email:
  

Password
  





Search Forums

(Advanced Search)

Forum Statistics
» Members: 323
» Latest member: Zymurgymaster
» Forum threads: 439
» Forum posts: 5,049

Full Statistics

Latest Threads
Powered Sharpener Setup R...
Forum: Relevant General Discussion
Last Post: grepper
7 hours ago
» Replies: 104
» Views: 4,428
Blade Taper Angle? - Supe...
Forum: All About Edges
Last Post: grepper
9 hours ago
» Replies: 0
» Views: 8
Edge Angle, Angle Guide, ...
Forum: All About Edges
Last Post: blgentry
03-27-2020, 12:01 PM
» Replies: 17
» Views: 266
Tricking the BESS Tester ...
Forum: Edge Sharpness Testing
Last Post: chino
03-26-2020, 08:31 AM
» Replies: 5
» Views: 40
More BESS Partners
Forum: BESS
Last Post: Mike Brubacher
03-23-2020, 05:09 PM
» Replies: 1
» Views: 324
Gritomatic Goniometer
Forum: Relevant General Discussion
Last Post: BeSharp
03-23-2020, 02:50 PM
» Replies: 26
» Views: 1,032
Micro-burr only in one si...
Forum: Burr Removal Methods, Testing and Results
Last Post: grepper
03-22-2020, 09:05 PM
» Replies: 7
» Views: 286
Trizact A6 & A3
Forum: Relevant General Discussion
Last Post: grepper
03-18-2020, 06:52 PM
» Replies: 9
» Views: 136
Toilet Paper Frenzy
Forum: Relevant General Discussion
Last Post: Mike Brubacher
03-17-2020, 08:56 AM
» Replies: 12
» Views: 190
The 5,000th Post
Forum: BESS
Last Post: chino
03-16-2020, 02:52 PM
» Replies: 4
» Views: 44

 
  Blade Taper Angle? - Super Easy Way To Know
Posted by: grepper - 9 hours ago - Forum: All About Edges - No Replies

Stay with me here.  At the end I’ll show how we can do this in only 15 seconds.
 
To calculate the taper of the blade all we need to know is the thickness of the blade at the spine and the width from spine to edge.
 
This is the knife from this post: http://bessex.com/forum/showthread.php?t...17#pid5317
 
The green/blue just shows the blade bisected into two triangles.  We know the thickness at the spine and the width from spine to edge.  Divide the thickness in half to get ½ the thickness.
 
   
 
Here is the triangle formed by ½ of the bisected blade.  Why do this?  Because now we have a simple triangle.  We know three things:  The length of two sides (2.012, 22.999) and one angle 90°.  This is cool because we can use SAS (Side Angle Side) calculations to get the length of the hypotenuse and from there the interior angles.
 
   
 
All that’s left to do are some quick and simple mental calculations to determine the taper angle is 5°.
 
   
 
Of course some (most?) blades get thinner at the spine from the handle to the tip.  Oh well, other than using a CNC machine with some complicated programming for sharpening, we’ll just have to live with it.  Maybe the best thing to do is to pick some mid point and call it good.
 
As promised, here’s how to do this in 15 seconds!  Go to either of these two web sites, select SAS calculation, enter ½ the spine thickness for one side and the width of the blade from spine to edge for the other side and 90° for the angle.  Press the GO button.  Done.

https://www.triangle-calculator.com/?wha...bmit=Solve

http://www.1728.org/trig4.htm

A Google search turns out many triangle calculators.

See?  Easy!

Print this item

  Tricking the BESS Tester (without meaning to)
Posted by: blgentry - 03-25-2020, 11:33 AM - Forum: Edge Sharpness Testing - Replies (5)

I just did some more work on my (now world) famous Tramontina kitchen knife.  The one that scored about 190-ish after very careful deburring, following a 380 grit belt.  Well I decided to polish it a bit so I used a 600 grit belt, then leather, scotchbrite, leather again.  Terrible scores!  200, 350...  So more polish.  I went straight to a smooth leather belt with green compound.  Very little compound left on the belt, but it's there.  Eliminated the remaining LOW.  ...and it scored 125, 125, 175.  The 175 was in the curve.  So back to the loaded leather.  I did 5 or 6 passes and got a little too casual with my motions.  Sliced open the top of my index finger.  Ooops.  Nice *cleeeeeean* cut though.  It didn't even bleed for 20 or 30 seconds.

After cleaning that up, I tested the curve again.   One handed, because I was holding pressure against the finger of one hand.  Balanced the blade on the fulcrum on the tester, and leaned it over to the media.  Lean, lean, lean, lean... and the media broke.  At 80 grams.  No freaking way.  I must have sliced it somehow.

So I went and got a bandaid and got my finger taken care of.  ...and tested again.  In the curve with the fulcrum, but this time with the other hand on the tip of the blade helping to guide it down.  ...and it read 135.  Now that's more believable.

I can only guess that with one hand the blade slips some and creates a slicing motion, which obviously "tricks" the tester because the force is not straight into the media, it's at an angle.  I think if you were really clever you could slide the blade sideways and get nearly zero readings by doing an extreme version of this.  Does that sound about right?

Anyway, seems like I need to be more careful when sharpening knives.  Smile

Brian.

Print this item

  Trizact A6 & A3
Posted by: MaxtheKnife - 03-16-2020, 03:13 PM - Forum: Relevant General Discussion - Replies (9)

for many years i have used A16's @ 1200 grit and i likem.

opinions on the next two higher grits A6 @2500 and A3 @ 4000.

i need some really super sharp blades for a butcher shop i just acquired for 1 of my exchange programs.  he has been happy with the A16's and leather after a two week exchange, but said could i make them sharper.

would it pay me to invest in the A6's and A3's...........or a better way to sharpen them to hold up better.

they get a lot of use.

i have tested toothy edges, but they do not work for him for two weeks.

let me know......................

Print this item

  The 5,000th Post
Posted by: Mike Brubacher - 03-16-2020, 11:02 AM - Forum: BESS - Replies (4)

4097

Print this item

  Toilet Paper Frenzy
Posted by: Mike Brubacher - 03-12-2020, 10:12 AM - Forum: Relevant General Discussion - Replies (12)

I've received several pictures from customers of empty toilet paper shelves in their local grocery stores lately. This, I presume, due to Corona Virus fears even though excessive trips to the bathroom are not a primary symptom of the disease. Fortunately, my mother saved all of her past copies of the Sears-Roebuck catalog and they remain, today, boxed up in one corner of a barn in Kansas. If any of our members find themselves in dire circumstances, please let me know what year and season you would prefer and I'll do my best to accommodate your order. Please do not request the Christmas edition - as a kid, that one was always much anticipated by me. 

You may have to be familiar with "out houses" and at least as old  as me to appreciate the value of this post but for those who do -  Smile

Print this item

  Isopropyl for parts cleaning? Good luck finding any
Posted by: grepper - 03-11-2020, 03:31 PM - Forum: Relevant General Discussion - Replies (4)

I keep isopropyl alcohol around for parts cleaning.  Sometimes it's just the needed solvent.  I like the 99.9% stuff so there is no water residue, but lesser concentration stuff works too in a pinch.

Need some for your shop?  Good luck finding any.  Herd mentality hoarding has set in and panic buying has wiped out store shelves.

As an aside, and FWIW, my wife is a large grocery store in the area.  She just texted me two pictures, one of the empty isopropyl shelf and the other of the shelf for toilet paper.  The toilet paper shelf is a BIG shelf, probably 20' feet long and 3' deep.  It is barren.

Print this item

  Edge Angle, Angle Guide, and Blade Body Angle
Posted by: blgentry - 03-10-2020, 03:48 PM - Forum: All About Edges - Replies (17)

As some of you know, I've been using grepper's KallyRest on my Kalamazoo sander.  It has an adjustable angle guide, which is a table/rest that you lay the body of the knife on.

In previous sharpening adventures, I've used flat stones and plates and used wooden wedges as an angle guide.  With these, you put the wedge on the stone and then lay the knife body on top of the angle wedge.

Many blades are roughly triangular in cross section, even before you get to the edge bevel.  If you measure the included angle of the BODY of the blade, you normally will find that knives vary from around 3 degrees inclusive to fairly large angles.  I just measured a Cold Steel Recon Tanto and it showed over 12 degrees inclusive. 

So, if you want to know the true edge angle, and you're using an angle guide like I'm describing, you have to take into account the angle "offset" of the body.  In particular, one half of the included angle is the offset.  For a 3 degree inclusive blade, the offset is 1.5 degrees.

With a wedge where you set the body on top of the wedge, the edge is being lifted up by the body.  So you have to add the offset to the reference angle.  For example, if you have a wedge of wood cut at 15 degrees and you put a 4 degree inclusive knife on top of it, you have to add 1/2 of 4 degrees, or 2 degrees.  15 + 2 = 17 degrees.  17 degrees is the true edge angle that will be ground in. 

Or said the other way, if you want a 15 degree edge angle and you have a 4 degree inclusive blade body, you have to account for the 2 degree offset:  15 - 2 = 13.  You need a 13 degree WEDGE in order to produce a 15 degree edge angle on a 4 degree inclusive blade body.  

Here's where it gets interesting to me.  I've been doing these calculations for years and was pretty comfortable with them.  When I got the KallyRest and later an angle cube, I planned to do these calculations to put some really low edge angles on a few blades.  I'm planning on doing a few at 12 degrees per side and 10 degrees per side.  I started to do the subtraction in the previous paragraph and something didn't seem right to me.  I thought about it and drew some pictures.  It turns out with the KallyRest (or any similar "angle table") the math is backwards!

You see, with the KR, the angle is not a wedge you are sitting on top of.  Instead it's a SPACE between the table and the abrasive.  So, when you set the blade body on the rest and it has (for example) a 4 degree included angle, you are getting CLOSER to the abrasive.  With an angle wedge the body lifts further away from the abrasive!  The tool rest is backwards from this.  You get closer to the abrasive, therefore the edge angle is DECREASED by the body of the blade.  Wow.  I know, I know, it's just basic geometry but for me it was a wow moment.

Which means that if I set the KR to 15 degrees and I put my 4 degree (inclusive) blade body on it, I'm going to be grinding in a 13 degree edge angle.  Or said the other way, if I want a 15 degree edge angle on my 4 degree blade body, I have to add the offset.  15 (edge) + 2 (offset) = 17.  I need to set the KR to 17 degrees in order to get a 15 degree edge angle on this 4 degree blade body.

One of the blades I want to take to somewhere between 9 and 11 degrees (edge angle) is a full flat ground Delica.  I've measured it's body angle at 3.7 degrees inclusive.  So to take it to 11 degrees (edge). I need to set the KR to:  11 + (3.7/2) = 12.85 degrees.  Neat.

I might make a video about this.  I'm not sure if the words I've written are clear enough to get the meaning across.  Let me know if this makes sense and/or if anyone would like to see a video about this subject.

Thanks for reading.

Brian.

Print this item

  Sharpening story - pesky knife to sharpen
Posted by: grepper - 03-03-2020, 11:31 PM - Forum: All About Edges - Replies (6)

I was given a dozen knives to sharpen, 6 steak knives, 4 8” chef’s knives and a couple of shorter santoku.  Nothing special, just average good quality knives.  Except for one they were Henckels type variety with modern sealed mostly impervious to anything plastic like handles.  You know the type.
 
One however had a wood handle.  The handle was totally dried out and starting to show small cracks.  The type of damage that occurs during the heat cycle in a dishwasher.  I didn’t think to take a picture of it because it was just another knife.  Nothing remarkable, just a wood handle knife.  It looked exactly like this one I found on ebay. 

   
 
I checked it out before I sharpened it and there were a number of small chips in the edge.  The chips weren’t very big.  I didn’t think much of it and went about sharpening with my usual method using a 150 grit Cubitron and deburred with a Scotch-Brite belt.  When I was done I checked it out and the chips were still there.  Crap!
 
So I reground the edge but the chips seemed to propagate.  I couldn’t seem to grind away the little chips out of the edge.  Very frustrating.  So I reasoned that maybe the 150 grit was too coarse and switched to a used 180 grit Deer ceramic belt.  For whatever reason that worked and removed the chips.  Then I deburred as usual with the S-B belt.  The blade was nice and sharp, well deburred and no doubt not bad at all.
 
But… the 180 grit belt that I used was pretty old and no longer really 180 grit.  I imagined that that I was not giving the guy as toothy an edge as I would like.  So, I started over and reground the edge with the 150 Cubitron.  This time, for whatever reason it worked.  No chipping. 
 
I’m not sure what was happening with that blade, but I needed to get rid of the chips with a finer grit abrasive before I could grind with a 150 grit for a nice toothy edge. The steel didn’t seem particularly hard but it was prone to chipping.  Live and learn I guess.  I spent well over an hour on that knife.  When I was done the sharpness ranged from 130-170 along the edge.  Not as consistent as I would like, but plenty sharp enough and nice and toothy. 
 
But I wasn’t done yet.  It was a nice knife and it bothered me that the handle was so dry and starting to crack.  I returned all the other knives but kept that one for two days.  I gave he handle a good thick coat of a combination of mineral oil, carnauba and bee’s wax.  Then put the knife over the heat register and let it all soak in for hours, wiped it clean and repeated the process.  I did that 3 or 4 times over the two days.  When done, the handle looked really nice and was in much better condition.
 
Unless it’s for a friend I actually charge for sharpening, but have no illusions about making any money doing.  I do it for fun because I enjoy it.  I charge $2.00 for less than 5” blades and jack the price up to a whopping $2.50 for > 5” blades, not counting really long blades like machetes.  Over many years I’ve made just enough to pay for the Kally.  What more could I ask?
 
Anyway, I think the guy got a good deal for $2.50.  Hope you enjoyed the story.

Print this item

  New BESS Partners
Posted by: EOU - 02-27-2020, 04:05 PM - Forum: BESS - No Replies

WE apologize to our new BESS Partners for not giving all the accolades they deserve but we do when we have the chance. Please welcome today's two new BESS Partners:

                                    BeSharp                                             and                                         Sharpest Solutions


                                                                                                                               



BESS Partners provide their customers with BESS sharpness numbers thereby contributing to consumer confidence and injecting an extra level of professionalism into their business. Why wouldn't they? As long as they own BESS certified edge testers and are small to medium size concerns - BESS Partnerships are free!

Print this item

  Dust mask for sharpening? - Good luck finding one
Posted by: grepper - 02-27-2020, 02:36 PM - Forum: Relevant General Discussion - Replies (4)

Need a dust mask for sharpening?  Good luck finding one… anywhere.
 
Due to COVID-19 fears (hysteria?) the shelves of local stores are deplete of masks and respirators.  Same with on-line suppliers.  Even the very large suppliers with deep inventory such as McMaster and other major industrial safety equipment, painter supplies, welding shops, etc., are wiped out of stock.
 
When I heard about the shortage I checked it out on-line.  I actually ended up spending a couple of hours at it going from supplier to supplier.  Sure enough, it was a futile effort.  Like chasing the proverbial wild goose.  There are still some wimpy large particulate masks around, but anything N95 or better rated are basically unavailable.  This is not good for businesses that need a constant supply of masks for the shop environment.
 
The whole thing gave me sort of an eerie-freaky feeling like actually seeing the seeds of one of those apocalyptic sci-fi movies unfolding before my very eyes.  Soon there will be roving disheveled hoards of the unwashed, clad only in tatters with newspaper wrapped in duct tape for shoes huddled around 55 gallon drums of smoldering trash for warmth.  Police drones will fill the skies in an attempt to maintain social order and seek out the newly undead zombie dudes stumbling around in search or living flesh for lunch.  (Sorry, I let my imagination get the better of me.)
 
But less humorously, if you need masks and/or respirators for a shop environment the outlook for sourcing any, especially in the near/foreseeable future, appears to be rather bleak.

Print this item