Flat Grinding Question

Michael J. Spangler

Michael J. Spangler

Joined
Oct 8, 2003
Messages
2,181
what do you guys think of flat grinding veritically on a contac wheel like bill moran does? i tried it today and it works fine for me. is there anything i shoud look out for? thanks a lot guys
 
Never tried it before Mike. You mean running it up and down the wheel like when you put in a false clip up top? Might be neat to try out.
 
I have seen a post on this, but can't remember where. It was just within the last couple of days.........maybe a week or so. May have been on the other forum (knifenetwork) It gave some pretty good info. Maybe a search would help.

Remember, many makers are grinding on a 2 inch wide belt, and are grinding horizontally. This means that only 2 inches of your blade are contacting the blade at any time (and even less toward the tip or any recurve).

If you grind vertically, and your grind area is a 6 inch long blade, the belt friction and resulting heat is greatly increased. Therefore, the time of belt-to-blade must be reduced with more frequent cooling cycles.

I can see how it might help with flattening a flat grind, or maybe even assisting in obtaining more equi-distant plunge lines (if you have a large enough flat platten and maybe using a pyro-ceram liner), however, remember that the side you are grinding is facing down, and you can't really see much of what is going on unless you are laying on a creeper and grinding overhead :D .

Enough of my ramblings.........my pea-sized brain is starting to hurt.
 
If he's using a contact wheel though, won't the blade only be touching a small part of the belt? Like this:
1iehon

I'm confused... :confused:
Of course it doesn't really matter cuz I don't use a contact wheel :p :rolleyes: I hope to someday though.

~Brian
 
Brian:

Again, I am speaking ONLY for me.......The only time I use the contact wheel is when I am doing a "hollow-grind" blade, and then it is in the horizontal position.

I would imagine that trying a vertical grind on the contact wheel might be a rather "wavy" ride.

I am sure that someone out there may have mastered the technique, and maybe with lots of practice it is possible. It just won't be me trying that method.

I am gonna be quiet now before I bite off more than I can chew. I will let the "Pros" chime in with their knowledge.

Robert
 
OK, I just misunderstood your post. And yes, I think it would be rather wavy too.
 
Hey Mike. I've done it from time to time, usually in conjunction with flat platten work. I think it can be really effective. I think the main thing to avoid is stopping at any point with the blade in contact with the wheel as it will tend to eat into it. You have to keep it moving, preferrably evenly. I would still save the plunges for the flat platten though.
Unless of course youre Rob Hudson. I think he does his on the wheel, but they are a gradual thing rather than the sharp plunges most people are trying to do. Rob does have a good point though about his way being stronger......No stress risers there....
Ed
 
Most of you guy's might think this is strange but I have never ground or sanded a blade on a platen. The way I learned was to hog off all the stock on a 8" bench grinder , horizontally, and then to sand the blade vertically on a contact wheel. Thing is, the blades were polished out, again horizontilly, using a "glued up emery wheel" which is basically 3 sewn muslinwheels glued together with emery abrasive glued to the face of the wheel. This is definitely old school stuff. I learned it at the Randall shop and the "Old Man" Bo Randall learned it from an English cutler he hired.
I was at the Gator Cutlery club show in Lakeland FL this weekend and I saw a knife that had been polished vertically on a contact wheel and the way I could tell is that it had waves on the blade when you looked at it at an angle.
My 2 cents worth is that this may work to get the blade flat on the vertical plane but you won't be flat on the horizontal plane. Perhaps if you hog off the material vertically and then switch to the horizontal on a platen you would you could get the best of both worlds.
Dwight
 
I do 99% of my grinding on the contact wheel except when hollow grinding and as far as I am concerned that is the only way to go. The blade will not be as wavy as you may think if you use sharp belts and keep the blade moving. I can do ether a flat grind (if you use a FLAT wheel) or a convex grind. The sparks will show you where the blade contacts the wheel which makes a lot of things easer. I do not have a plunge on these blades as I feel thy are a week spot in the blade. To hand rub these blades I use a rubber sanding block that I get at the hardware store, the kind that has a slit in each end with nails to hold the sand paper, thy are 3" wide so I cut them into 3-1" wide stripes with a nails in each one, Use the flat side for convex blades and the curved side for hollow grinds. Hope this helps. Gib
 
Mike you handled my Necka comp knife yes you guessed it,
but in a way, it is flat at the ricarso to a slight Hollow and to a convex for the tip. that was fun..grinding vert to a 45 deg at the
tip.
 
It is a good way to flatten out a grind if you have no shoulder to consider. If you have a shoulder you will have to stop before you wipe it out and finish that area with a file.

Waves are a beginners problem, they go away with practice.

Belt life begins to suffer however using this technique, there is usually not enough pressure to keep the belt sharp and the grains glaze over quickly.

Almost all of my blade grinds are flattened this way as are all my blade flats.
 
awesome thanks for the info guys. so thats how you did it dan??? yeah i've ept the waves down to a minimum. i find at a speed of 1750 rpms if you use the sharp belts and you you keep the blade moving you're just fine. i'm wiping out the plunges and blending right into the ricasso. hopefully i can finish one today or soon and post a pic for you guys
thanksagain
 
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