Good Tips, On Good Tips

Included in the paltry price of a Washboard Kit are hand rendered instructions for this concept (on both a horizontal surface, and an incline) and much, much, more....:D

03_zpsb35802e0.jpg


10_zps5a80a656.jpg
 
I must say that the instructions for the Washboard system are THE best instructions I have ever received with any product ever! They actually instruct! Martin, you should go show them how it is done over there at IKEA, lol!
Btw, I am using my Washboard right now to but the final touches on an edge before I ship it out.
 
reapinItUP said:
Very cool illustrations. sharpening for dummies... lol
Click to expand...

The devil's in the details, I always seem to grasp physical concepts better when presented as drawings, sometimes even more useful than video.

Occurred to me if you tilt your head 45* on that last incline illustration you get a decent perspective view of the progression around the tip when working with the block horizontal.

Next up might be a flip book - gotta keep it old school!
 
flatblackcapo said:
I must say that the instructions for the Washboard system are THE best instructions I have ever received with any product ever! They actually instruct! Martin, you should go show them how it is done over there at IKEA, lol!
Btw, I am using my Washboard right now to but the final touches on an edge before I ship it out.
Click to expand...

Can you believe I once got turned down for a job as a technical illustrator!? Something about needing straight lines every now and then...
 
bgentry said:
Understanding the geometry of the belly and tip is important as it helps you figure out how to move the blade on the abrasive to keep the bevel flat. That's really what you want: For the edge bevel to be in flat contact with the abrasive through the entire length of the edge, starting at the hilt and ending at the very tip of the tip.

Watching the tip as you finish your stroke really is quite instructive. I found that I wasn't lifting the handle *nearly* enough to make contact with the tip. Once I did, my tips starting becoming sharper than any tips I had ever made, let alone felt from the factory.

To understand the geometry better, Ken Schwartz has an amazing video that makes it all seem very simple. I am very impressed with how he presents this.

Brian.
Click to expand...

Hi Brian,

My thoughts recently have been about the belly of the knife also. And originally, I was doing it as the video showed. But I switched to something different but because of the video which confirmed my original thinking, I'll switch back.

But however, what caused me to switch is because if you do as the video stated, the "effective bevel margin" or the width of the resulting bevel as it goes around the belly and near the tip increases. And I think people find that less aesthetically pleasing. The wider bevel is because generally, the thickness of the blade around the belly increases in line with the rest of the blade coming from the straight edge. (I hope I'm explaining myself right.)

I think people adjust so that the actual angle around the belly and near the tip increases to maintain the same bevel width.

Have you come across the same issue in your thoughts?
 
Rey HRH said:
But however, what caused me to switch is because if you do as the video stated, the "effective bevel margin" or the width of the resulting bevel as it goes around the belly and near the tip increases. And I think people find that less aesthetically pleasing. The wider bevel is because generally, the thickness of the blade around the belly increases in line with the rest of the blade coming from the straight edge. (I hope I'm explaining myself right.)
Click to expand...

I don't claim a lot of expertise on this, but I have studied it some and I have my opinions. If a blade's thickness is constant from hilt to tip *and* the blade tapers back towards the spine at the tip, then YES, the stock becomes thicker at the edge as you approach the tip. Therefore, if you want to maintain the same angle from the hilt to the tip, then the bevel width necessarily MUST become wider as you get into the thicker part of the blade. So the bevel width will be constant through the straight part of the blade and gradually get wider and wider as it gets to the tip. Again, with a constant bevel angle and stock that is getting thicker as the edge moves back towards the spine.

I made this observation to Ken Schwartz on another forum, when discussing how to properly sharpen bellies and tips. Ken replied that I *would* be correct, but that very few blades are ground like that. He said that most blades have Distal Taper. Which means that the overall thickness of the blade is reduced as you reach the tip. If the distal taper is perfect, then one could maintain a constant bevel angle *and* a constant bevel width, even though the edge was getting closer and closer to the spine as the tip is approached. This makes sense to me.

But I think the amount of distal taper varies a bit, and is no where near perfect on a lot of blades. Which leads me to your point here...

I think people adjust so that the actual angle around the belly and near the tip increases to maintain the same bevel width.
Click to expand...

So yes, if the thickness of the blade stock, AT the edge, is thicker near the belly and tip, you would need to increase the edge angle in order to keep the edge bevel width constant. The amount you need to do this depends on the geometry of the blade, and will differ a bit from blade to blade.

I demonstrate how I do this a little bit in my WorkSharp Ken Onion freehand sharpening video. It's just a bit of a rock of the blade as you go through the belly and get to the tip. When sharpening by hand, I tend to use my off hand to apply pressure to the blade towards the abrasive. This allows me to sort of feel when the bevel is FLAT against the stone (or belt) so I can maintain the bevel that's already on the blade. Assuming that the bevel that's on the blade is close to correct already. This technique is my Secret #1 of sharpening: Feeling the bevel on the stone.

This stuff is rather difficult to describe properly with just words. I hope this made sense.

Brian.
 
bgentry said:
This stuff is rather difficult to describe properly with just words. I hope this made sense.

Brian.
Click to expand...

Made sense to me as I came across the same realization.

I've tried both ways. I think I'm going with the functionality and maintaining the same angle even though the bevel width won't appear uniform throughout. Thanks for your thoughts.
 
bgentry said:
I don't claim a lot of expertise on this, but I have studied it some and I have my opinions. If a blade's thickness is constant from hilt to tip *and* the blade tapers back towards the spine at the tip, then YES, the stock becomes thicker at the edge as you approach the tip. Therefore, if you want to maintain the same angle from the hilt to the tip, then the bevel width necessarily MUST become wider as you get into the thicker part of the blade. So the bevel width will be constant through the straight part of the blade and gradually get wider and wider as it gets to the tip. Again, with a constant bevel angle and stock that is getting thicker as the edge moves back towards the spine.

I made this observation to Ken Schwartz on another forum, when discussing how to properly sharpen bellies and tips. Ken replied that I *would* be correct, but that very few blades are ground like that. He said that most blades have Distal Taper. Which means that the overall thickness of the blade is reduced as you reach the tip. If the distal taper is perfect, then one could maintain a constant bevel angle *and* a constant bevel width, even though the edge was getting closer and closer to the spine as the tip is approached. This makes sense to me.

But I think the amount of distal taper varies a bit, and is no where near perfect on a lot of blades. Which leads me to your point here...



So yes, if the thickness of the blade stock, AT the edge, is thicker near the belly and tip, you would need to increase the edge angle in order to keep the edge bevel width constant. The amount you need to do this depends on the geometry of the blade, and will differ a bit from blade to blade.

I demonstrate how I do this a little bit in my WorkSharp Ken Onion freehand sharpening video. It's just a bit of a rock of the blade as you go through the belly and get to the tip. When sharpening by hand, I tend to use my off hand to apply pressure to the blade towards the abrasive. This allows me to sort of feel when the bevel is FLAT against the stone (or belt) so I can maintain the bevel that's already on the blade. Assuming that the bevel that's on the blade is close to correct already. This technique is my Secret #1 of sharpening: Feeling the bevel on the stone.

This stuff is rather difficult to describe properly with just words. I hope this made sense.

Brian.
Click to expand...

I may not be understanding you totally, but I agree for the most part with what you are saying. It totally depends on how the one who did the grind sets up the primary bevel/grind.

For example... I could take the same knife and do it one of three ways: make the grind thicken up near the tip (i.e. lower the grind height toward the tip), keep the grind consistent from heel to tip (matching the edge), or make it get wider toward the tip (like a hinderer slicer grind). So it doesn't necessarily have to have a thicker tip or a steeper angle at the tip - it is dependent on the maker. When I regrind a blade, for the most part, I keep a consistent, same-angle edge from heel to tip (sometimes I even widen it up on purpose, like for a hard use knife for more prying strength).

But over use, regardless of the grind, most people's tip will widen up if you are keeping the same angle because the tip is probably the most used section of a knife. and if you want a nice pointy tip, with every sharpening you have to remove more at the tip then the rest of the blade.

I think people adjust so that the actual angle around the belly and near the tip increases to maintain the same bevel width.
Click to expand...

Exactly... and the way you can tell is simply with a caliper. Measure the shoulder width at the heel and belly then again at the tip. Even though it may look the same from the side, that is deceptive and it can actually be much thicker at the tip.

Most people, when sharpening on a belt sander, widen the tip up as well. To combat this you must practice very carefully ;) depending on your method (edge parallel to the floor or spine parallel to the floor and rocking the handle out). It can be done either way with practice.
 
Last edited:
Knives that are built for heavy use can take this approach, but not so much with kitchen cutlery where a very thin tip and consistent distal taper are needed or at least should be the goal.
I tend to "cheat" more with hunters and camp knives; creative grinding is maybe a better word. I've been focusing on Kitchen blades lately and find I'm working more from the edge backwards towards the spine. This order of thinking seems to produce a better tip and belly bevel geometry than if I concentrate on the entire knife, the look of the knife as finished.

Fred
 
You must log in or register to reply here.
Back
Top