WW . . how sharp can we get it. .Let's try

[wingnut]

So I guess what I'm hearing or in this case seeing is that the WW design with a 60 degree bevel is only going to get so sharp without reengineering the head and making it something else.

My original premise was that I was going from "file sharp" to "razor sharp" and I've done that to my satisfaction.  Unfortunately I have not had a chance to test the exit sharp theory.  Need a pig to stand still long enough to get 'r done.  

I'll keep you posted.

Mike

[Sharpster]

Mike,

That's not entirely correct. Lin Rhea and I were discussing this not long ago. Many people confuse sharpness with performance.

In theory, a cutting edge should terminate in a true and complete intersection of two bevels with no flat at the edge. Unfortunately, even the finest stones or rouges cannot produce a cutting edge that measures 0.00000. Even the sharpest straight razor has a microscopic "flat" on it's cutting edge. Sharpness is defined by the width of this flat as measured in the tens or hundreds of thousandths and it has nothing to do with bevel angle.

If we sharpen two knives (or broadhead blades) separately, one beveled at 90 degrees (45 each side) and another at 15 degrees, (7.5 each side), there is no reason we could not attain the same level of sharpness on both. Both could shave hair easily. Where we would see the difference is in performance of the cutting edges. The 90 degree edge would not slice a tomato nearly as easily as the 15 degree edge because of the increased "wedge effect" of the 90 degree edge. The actual cutting edges are equally sharp but, the steep angles of the bevels impede the 90 degree blade from penetrating the tomato because of the abrupt wedge immediately behind the cutting edge. This is what Ed Ashby refers to as the "MA" or mechanical advantage of the bevel geometry.

Now if we were doing some serious chopping the 90 degree edge would hold it's level of sharpness exponentially longer than the 15 degree edge would because the 90 degree edge is very well supported and re-enforced by the same wedge shape that caused it to perform poorly on the tomato.

There is also the separate MA of the broadheads overall design. This is where the 3:1 ratio decreases the resistance to penetration over shorter, wider designs for exactly the same reason above but in a different direction or plane.

Long and short of it is- Yes, you can get your WWs every bit as sharp as any other blade on the planet.

I'm a devout two blade shooter but, it's not because I think two blades are superior by design, for me it's an accuracy issue. I just get consistently better groups with two blades and shot placement trumps all else. I'm also a sharpening nut and it's easier to get a two blade crazy sharp than a three blade (for me).

As bowhunters we want to do as much damage as possible with the one shot we generally get so, following that logic, a multiblade head would be the best choice provided that we can get that head every bit as sharp as a two blade AND get excellent groups too. The recipe requires all the ingredients to work properly and can be tough to put together consistently.

 

Ron

[Doc Nock]

Yeah, what he said!    

And then that whole thing about how well the blade holds up as it passes through a bunch of different mediums inside a critter from hard stuff to gooshey stuff!  

I had talked to some friends who had a hog hunting operation in OK...they said that they'd usually find any "lost" bow hit hogs and the gal did a necropsy--which at that time, often revealed the real pointy 3-blade style of heads the tip rolled over if it caught the shield or other heavy obsticles and limited penetration.

Course', that's not to say they were good and sharp going in (or staying that way)so nothing universal can be learned from anecdotal evidence.

Where at least in Ashby's stuff, while not scientific, he could alter one variable at a time and then check for repeated penetration behaviors--which is pretty scientific come to think of it!  

[freefeet]

Originally posted by Sharpster:
The actual cutting edges are equally sharp but, the steep angles of the bevels impede the 90 degree blade from penetrating the tomato because of the abrupt wedge immediately behind the cutting edge. This is what Ed Ashby refers to as the "MA" or mechanical advantage of the bevel geometry.

Now if we were doing some serious chopping the 90 degree edge would hold it's level of sharpness exponentially longer than the 15 degree edge would because the 90 degree edge is very well supported and re-enforced by the same wedge shape that caused it to perform poorly on the tomato.

There is also the separate MA of the broadheads overall design. This is where the 3:1 ratio decreases the resistance to penetration over shorter, wider designs for exactly the same reason above but in a different direction or plane.

This is exactly what i was referring to in my last post as "effective cutting edge".

A 90 degree edge will not cut as cleanly as a 30 degree edge if they are used going straight on, perpendicular to the edge, but it will cut as cleanly if it is moved so the cut hits the edge at an angle.  The effective cutting edge of the 90 degree edge can easily be made 30 degrees by slicing at something like a 30 degree angle.  At the same time the 90 degree edge retains all the longevity properties of a 90 degree edge.

[SlowBowinMO]

I'm a sharpness nut as well.  I shoot broadheads year round, and probably 10 to 1 over field points.  Point being I shoot a LOT of broadheads.

It has been my observation that the hard steel of the Tuskers and Grizzlies hold their edge exceedingly well.  Second place for edge retention goes to Woodsmans/Snuffers in my observations.  The steel in those heads is only 45 HRC but I believe the blade angle helps them hold their edge.

If I take a typical 2 blade head of the average 48 to 50 HRC, I can get a wicked edge on them but it definitely doesn't hold like the Tuskers and Grizzlies IF I take them down to a very shallow blade edge or single bevel them.  If I leave them double bevel at the factory angle they will not be quite as sharp to start with but they will hold the edge pretty well.

We need to remember that the quality of steel has a lot to do with the performance of the single bevel.  What good is a dull single bevel?

[Kingwouldbe]

Originally posted by calgarychef:
.......
 I'd also venture to say that anyone doing it freehand ie:   holding the arrow in one hand and the sharpening device in the other hand won't ever get a really sharp edge.  I clamp mine in the vise so there is minimal movememt.    Movement of any kind equates to an edge that will be off "kilter.."

There are some who teach to file sharpen there Boadheads freehand, like they saw Fred Bear do it 45 years ago in hunting camp, obviously it works and has worked, I've done it.        

Like O.J Simpson, the evidence is overwhelming, you can ignore it, that's your choice, however, post like this one will help everyone learn what is really sharp, verses kinda sharp.

To me it's like the razor I use, at first it cuts effortlessly, and when I cut my self, I don't even know it until I look in the mirror, the amazing thing is, I can't stop it from bleeding until I apply direct pressure for quite some time, and this is only skin, not a vain or artery (Thank God) you could never get it to stop before you dropped dead.

As the blade is used a few times, it begins to hurt and cause razor burn from scraping my skin, it's still sharp, and cuts, just not as good as it once was.

I want a edge as sharp as it can be, why? so it bleeds and bleeds and bleeds, just like when I get nicked while shaving.

Learning to get a razors edge is an acquired skill, with practice and dedication any one can learn to get a razors edge.

[Jeff Strubberg]

I want a edge as sharp as it can be, why? so it bleeds and bleeds and bleeds, just like when I get nicked while shaving.

Sure.  THe question is, how sharp is that edge after coming out of your quiver and passing through the hair and hide of a game animal?


You can create an edge on a broadhead that will scare a surgeon.  That doesn't necessarily mean that edge will be more effective.  The edge also has to be durable.

[Sharpster]

Originally posted by SlowBowinMO:
It has been my observation that the hard steel of the Tuskers and Grizzlies hold their edge exceedingly well.  Second place for edge retention goes to Woodsmans/Snuffers in my observations.  The steel in those heads is only 45 HRC but I believe the blade angle helps them hold their edge.

We need to remember that the quality of steel has a lot to do with the performance of the single bevel.  What good is a dull single bevel?

Absolutely right Slowbow! The quality of the steel is another ingredient in the recipe that's critical to the cutting edge's durability, be it a single or double bevel or a knife or razor blade.

Somewhat more durable cutting edges can be created on softer steel blades by increasing the bevel angle, but better steel = a better broadhead, no matter how many blades or bevels the head may have.

Ron

[Kingwouldbe]

Originally posted by Jeff Strubberg:
[Sure.  THe question is, how sharp is that edge after coming out of your quiver and passing through the hair and hide of a game animal?
 durable.

Jeff, 10/4, The hard caked mud, hair, gristle, fat, muscle, and bone will test every part of our equipment.

If it was dark when I shot this Boar, I'm sure I would of seen sparks,LOL

I think Doctor Ashby said: 25-30 edge degrees was the best of both worlds, sharp and strong, of course with good steel.

To thin and it could curl, to thick and it will impede penetration.

[Steve O]

KWB,

Do you have a zoomed out photo of that one?  I am guessing you opened that up from the wound to the top of the pig?  The broadhead didn't do ALL that did it?

Isn't it time for some more hog hunts out there...the dangerous game forum is lacking right now!

[d. ward]

I'am not sure you could get the angle correct on a WW,but in 1957 Howard Hill did not need no shaveing sharp broadheads.I'am not tring to be funny just another view...bowdoc

[d. ward]

...bd  

[d. ward]

[Kingwouldbe]

I love'ya Bowdoc, they use to use leeches and drain your blood when you where sick, glad we stopped using them also.

We have more information now than Howey or Freddy had.

 

Steve o, The arrow went in just where the coagulated blood is, I wanted to show how much STUFF you have to go through just to get inside.

I hear'ya freezers getting then on pork.

[Kingwouldbe]

Originally posted by the real bowdoc:
 

Bowdoc, Howard is ripping a serrated edge on this head, buy running the file backwards on the edge.

I have used this    in the field to get a edge on a shot broadhead, it's a 2nd best edge. lol

[d. ward]

I been using that same type serrated edge myself for well lets just say sometime now and it sure works great for me.However I just read some doctors are going back to the leeches as it worked far better then a Rohr 714 does..bd

[Steve O]

That full pic helps me visualize much better, thanks.  That is all behind the shoulder?  That one must have looked like an Abrhams in front of it!

[calgarychef]

King it works to do it freehand, I've done it too. I do my knives freehand on a steel and on a stone. But there aint nobody in the world who can make it as consistently sharp freehand as when it's snugged up in a vise, even if your name is Fred!!  

the chef

[Steertalker]

There's sharp:
 

And then there is down in less than 7 seconds sharp  
 
 

Brett

[Talondale]

Sure.  THe question is, how sharp is that edge after coming out of your quiver and passing through the hair and hide of a game animal?


You can create an edge on a broadhead that will scare a surgeon.  That doesn't necessarily mean that edge will be more effective.  The edge also has to be durable. [/QB]

I'm not a sharpening expert.  Far from it.  I'm just now getting to where I can put a decent edge on a blade.  But I can do logic and your arguement is working against you.  If you are concerned about how sharp a very sharp blade will be after coming out of your quiver and passing through the hide and hair of an animal think how more critical that is if you only start out with a moderately sharp blade.