Art of Grinding

Another point I'll add, or perhaps expand upon: A good grinder will reduce the learning curve immensely, IMO, and even more so with a VFD. It makes a huge difference when everything is nice and solid, set up squarely, wheels are balanced, etc... and being able to slow down or speed up precisely and easily can really make a difference as well.

Even with the best jigs, or all the talent for free hand in the world: if you've got a dished out platen that's cocked to the side, with poor tracking, and a machine that's wanting to walk off the bench, you're going to have a bad time.

On the other hand, if you're starting out with something like a TW-90 or a Northridge, or what have you, you're probably going to reduce the learning curve significantly.
 
razor-edge-knives said:
In theory yes you are correct (that a jig can work very well for a nmg), and it will work to an extent. But if you want a nice arc in between the two plunges then you will have to do it free hand or sacrifice edge geometry. For an example: here is a reblade for my RHK I was messing with and did on a jig. Notice that it's a straight line from plunge to plunge.

i-2JXHWFK-X2.jpg


The problem is that the edge thickness will vary if you want a nice arc like on this one (note: not my pic, just pulled it off of google). Notice that the heel and near the forward plunge gets thicker/wider

eb2c8ed7a6828c62efec447c8707e113.jpg


The reason for this is that the angle must change near each plunge to get a little steeper (e.g. if you are grinding the main hollow at say 3 dps, then it will need to increase to 5 dps near each plunge to keep the edge geometry even). If you have a fixed angled jig (which every one out there is that I know of) then to get the arc your grind will naturally get thinner in the middle.

That all being said is just to demonstrate my point that jigs are limiting but don't require as much skill, free hand is total control/power but requires a lot of learning and skill. Jigs are great in certain situations though, very nice indeed!
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You can tell he jigged it up by exactly what you said and the scratches. You can hide the thickness problem by using a larger diameter wheel or flat grind it and you will maintain the thickness.

I can freehand that grind probably faster any any jig. I don't have anything against jigs but I just spent so much time learning freehand that it's just what I do now. In the future when I become more shaky do to my arthritis and cp I will be forced to jig it up...
 
Pittknife said:
I can freehand that grind probably faster any any jig. I don't have anything against jigs but I just spent so much time learning freehand that it's just what I do now. In the future when I become more shaky do to my arthritis and cp I will be forced to jig it up...
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Good points!
 
Hello Eric. I looked at a couple of knives in the Arizona Custom Knife Gallery that had your name on I think.Yes they looked good but why who you say those can't be done with a jig? What I suggest to use and after some practice with that jig of mine they are quite doable. But perhaps you do others you figure cann't be done. No, I can't show you mine like those since I only do liner locking folders. Frank
 
Brock Cutlery said:
This sounds about right Kevin. I think there is such a thing as talent. My dad played guitar really well and could sing. Although I tried for many many years and got fairly good at it, I never had the feel for it. It didn't seem natural to me and I just mimicked what I heard. Grinding however feels very natural to me now. And as you can say, I can feel when it is right and when it isn't.
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Let me add this for the OP.^^^ You will find a "Sweet Spot!" like swinging a bat on a softball or a spot on a Tennis racket or for me, the sight picture, hold, and stance with my Pistol when I just know, where the bullet is going!

When you present the blade to the belt with just the right amount of pressure and speed on a certain grit belt you will know how the steel will abrade!

This won't happen over night and my sweet spot for belt, speed, pressure at a given grit may be totally different than yours,,, But you will find your Sweet Spot! Where you know its right!
 
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Rhinoknives1 said:
Let me add this for the OP.^^^ You will find a "Sweet Spot!" like swinging a bat on a softball or a spot on a Tennis racket or for me, the sight picture, stance and hold of my Pistol when I just know, where the bullet is going!

When you present the blade to the belt with just the right amount of pressure and speed on a certain grit belt you will know how the steel will abrade!

This won't happen over night and my sweet spot for belt, speed, pressure at a given grit may be totally different than yours,,, But you will find your Sweet Spot! Where you know its right!
Click to expand...

http://freakonomics.com/podcast/peak/

Great podcast about if talent is a real thing
 
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