Off Topic Part 3 of the saga...I'll never use a grinding jig again.

N.W. Gean

N.W. Gean

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Oct 10, 2018
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I'm still not happy with the grinds to the degree of showing pictures, but I took a scrap knife with wavy bevels (from the jig) and made it into a respectable shop knife. I did it with freehand grinding. Ever since I got the glass platen, it's all been clicking. Suddenly I can find the bevel with my hands and hold the angle, even get a decently straight line. Even my weak side isn't the worst anymore. I'm still having trouble grinding the tip of the knife and getting the belly symmetrical, but I think there's light at the end of the tunnel here!
 
Glad you came over from the dark side. All it takes is some practice and you will start to feel the knife on the platen.

I have seen video of Ron W. Wilson grind a bevel, either hollow or flat, in a few passes on a screaming grinder. They were perfectly made every time. He said it took him a few years to get it down really well, and after that he did it for 50 years with no problems.
 
I'll probably pickup some edm stones to help straighten out grind lines, but in the end I know I'll be a better grinder if I stick with freehand. The problem I've had with my sled jig is it feels so clunky, and I can't feel where the bevel is at.
 
If I understand correctly, my 1800 rpm motor with a 5" drive wheel is pushing about 2300 spfm. That seems to make mistakes fairly fast for me, so I can't imagine moving 2.5 times that :eek:
 
Doing my rough grinds I run the motor on my KMG TX full out. I dunno how fast it is, but it eats metal.

Once I'm in the finishing stages I slow things way down
 
R.C.Reichert said:
What is the best belt speed for grinding freehand? My grinder runs at only one speed...5200 sfpm.
Click to expand...
That’s good for hogging or grinding with the lower grits, but when I move above 120 I have to slow way down. I can’t imagine 300 grit at 5200 sfpm, you’d heat the steel up very fast.
Are you able to install a pulley system?
Or better yet a vfd and a 3 phase motor.
 
Josh Rider said:
That’s good for hogging or grinding with the lower grits, but when I move above 120 I have to slow way down. I can’t imagine 300 grit at 5200 sfpm, you’d heat the steel up very fast.
Are you able to install a pulley system?
Or better yet a vfd and a 3 phase motor.
Click to expand...


Thanks! That's pretty much all I use it for is hogging off metal. When I need to go slower for a flat grind and finer belts I switch to my 6x48 belt sander that goes much slower. At least that's what I'm doing for now. My grinder is a Multitool that I converted into a 2x72. I could put a pulley on the other side of the bench grinder, but I actually really like using the bench grinder's stone wheel for some of the finer initial profiling.
 
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