Getting nice plunge lines.. anyone chamfer the edges on their platen?

LARRYZ10

LARRYZ10

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Feb 6, 2010
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I hollow grind 95 % of my sporting knives because I like the look and my contact wheels have worn edges that look like they have been chamfered lightly. My plunge lines have evolved as a result to a more pleasant looking rounded line. I recently bought a new 10 inch wheel and noticed right away how sharp and squarish the plunges looked so I carefully sanded a small radius on the edges of the wheel and my plunge lines look good ( to me ) since doing it. I wondered if the same thing would be desirable on my flat platen. I have a "Nathan the machinist" platen with a chiller and I hate the thought of experimenting with it. Is it a good idea to chamfer the edges of a flat platen? Any thoughts? I see that Nick Wheeler uses a chamfered edge on a flat piece of steel covered with sandpaper to clean up plunges on his fighting knives after grinding. Thanks, Larry P.S. Here is a photo of a knife ground on my newer 10 inch wheel. LL

KStRZ9gl.jpg
 
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Sometimes I use a grinding jig(blade clamped to angle iron) and it makes it east to get my plunge were I want it. I just leave a good amount more and then once the bevel is ground in I'll go back and grind in the plunge. Having the blade in the jig holds it exactly where it needs to be to grind on the plunge. I can get a real close view of it and get real detailed since I'm not having to position myself to hold the blade.

I wouldn't say you'd "need" to chamfer the edge of the platen to make more of a swooping plunge. You could just track the belt off the edge a tiny bit, leave some meat on the plunge, and come back and grind it in. When you grind it in just use real light pressure and make a small radius.

In all honesty I'm not sure how it would even work with the chamfered platen edge. I'd imagine you'd want to run the belt a little loose so it wasn't so rigid and not conform to the radius. I was thinking about doing this to one of my KMG platens on the top. What kind of grinder do you have? You could always sacrifice a $20 platen for the cause.
 
I have an old stock KMG platen I could play with so that's not a problem. I suppose I could chamfer that platen and run a j-flex belt or lightly worn gator belt over the edge by an 1/8th inch and refinish the plunges after grinding the bevels or even just grind the bevels with the platen chamfered and the belt even with the edge of the platen. I am hoping someone has already tried this and can advise before I take steel off the platen. Larry
 
Chamfering the platen's edge is the way to go....carefully, since you want a consistent radius, the same on both edges.
Chamfered edges also help against the 2" mark in the bevel of the blade
 
I guess the question would be- is there a downside to chamfering the edge slightly? I don't see one, but perhaps someone has. Why not do it?
It reminds me of when I got an anvil that dated from the 1880s and had some collector value...and a badly chipped far edge, though it was nice and flat and clean elsewhere. I agonized for months over doing something about that, and it came down to...why not? And the only answer was, that at some unspecified time some unspecified person might want the anvil as it was- to sit in a collection in a barn somewhere. A dose of hardfacing rod and a few minutes with the grinder resulted in an anvil I've spent thousands of hours using.
 
Call me crazy Larry, but I prefer the aesthetic of a nice crisp shoulder with a tight radius in the plunge like you have pictured above. To me, it suits the style of knife you build. If you look at Nick's knives, or many of the other well known makers building that style of knife, most have very crisp and well defined shoulders with a nice minimal radius in the plunge line.
 
In my experience a chamfer, even a slight one, has a noticeable effect on the curvature of my plunges. When I first started on my 1x30 and even my 1x42 both platens had soft edges and I always seemed to get nice curved plunges with really no effort at all. Moving to my 2x42 and 2x72 that utilized platens with very sharp shoulders resulted in very sharp plunges. Took me a while to understand what was going on but I am positive the platen shoulders are the culprit. I have heard a lot of other makers talk about riding the belt off the platen and sweeping things in and while that works, I personally prefer to make things easier for myself. In my experience riding the belt off is a bit inconsistent and, at least for myself, is difficult to really know how much the belt is cutting. I have yet to radius my current platen but will doing so in the very near future. These blades below were all ground on a 1x30 about two years ago before I really started to have an affection for curved plunge lines. Basically, I wasn't trying to get the curves, the grinder did the work. Hope that helps a little.
Blessings,
Joshua

 
LARRYZ10 said:
I have an old stock KMG platen I could play with so that's not a problem. I suppose I could chamfer that platen and run a j-flex belt or lightly worn gator belt over the edge by an 1/8th inch and refinish the plunges after grinding the bevels or even just grind the bevels with the platen chamfered and the belt even with the edge of the platen. I am hoping someone has already tried this and can advise before I take steel off the platen. Larry
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Rounding the edges of the platen is just like tracking the belt off the wheel and bending the belt edges. I have 3 platen's I did in different radiuses and they work very well, unfortunately I got tired of taking them off just for bevels so I stopped doing it. I also hollow grind 90% now so I don't use them.

One thing is if you have a ceramic platen you won't be able to do it, I tried on a ceramic and the edges chipped very bad.
 
Pittknife said:
Rounding the edges of the platen is just like tracking the belt off the wheel and bending the belt edges. I have 3 platen's I did in different radiuses and they work very well, unfortunately I got tired of taking them off just for bevels so I stopped doing it. I also hollow grind 90% now so I don't use them.

One thing is if you have a ceramic platen you won't be able to do it, I tried on a ceramic and the edges chipped very bad.
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I had my brother round the edges of my new ceramic platen......he's a glass cutter in training, and he did an awesome job. So it is most definitely possible. I'll see about getting a pic up tonight.

Darcy
 
I am running Nathan's platen and I rounded the sides of mine and love it.
 
Adam, This photo is the "after" photo. I put a tiny chamfer on the rubber of my 10 inch contact wheel and I think this plunge is about right for looks. Larry
 
DEllis said:
I had my brother round the edges of my new ceramic platen......he's a glass cutter in training, and he did an awesome job. So it is most definitely possible. I'll see about getting a pic up tonight.

Darcy
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I'd love to see some pics, and maybe hear of what you're brother would recommend for guys to possibly do this themselves?
 
DEllis said:
I had my brother round the edges of my new ceramic platen......he's a glass cutter in training, and he did an awesome job. So it is most definitely possible. I'll see about getting a pic up tonight.

Darcy
Click to expand...

I'd love to see pics and also how he did it, I tried twice and started to get chips in the edges.

Thanks frank, I'll have to try it again with silicone carbide.
 
Not sure exactly his technique, but he said he used a belt grinder with a dull belt for the finish.
I'll post the new grinder pics when I get it done.
Darcy

 
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