Freehand grinding tips, and an introduction

B

bluebutcherbird

Joined
Jun 13, 2018
Messages
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I just wanted to say hello to everyone on BF. It's not my first account here but it has been many years since I last posted and never as a knife maker.
I have been trying to step up my game by finally learning to freehand grind. Before that, I was a bit of a coward and stuck to my beveling jig and chisel grinds. Symmetry is horrifying, but I can't improve if I don't even try. Here is my first freehand grind on a knife. My biggest issue was the plunge lines. Try as I might I just could not get them to be crisp and even.

Is this a problem with my technique? Or could it be my platten being a bit soft? If it helps my grinder is a grizzly 2x72. Are there any tips to improve my quality that I am unaware of?

Another first time project. I forged a rudimentary saya chisel. It is ugly as sin, but cuts quite well.

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First thing to do with a grizzly grinder, take off the graphite platen and grind it perfectly flat and smooth. This should help everything a bit.
 
Oh, ok great. The mild steel works fine but I highly suggest you get a glass platen. I finally got one and it is surprisingly effective. http://www.hightemptools.com/ceramicplatenliners.html

-A few tips for general grinding from a tips page that I wrote up some time ago. I hope they help you some:
-Let the belt do the work, but be sure you are controlling where it is working. Watching where the sparks come from helps you know where the blade is on the belt. Try to keep the sparks coming from the center of the belt, even when fixing a mistake that may have occurred. Only turn the blade tip towards you slightly when approaching the plunge to avoid the '2 inch line'

-Keep your blade cool, a hot blade makes you hurry and jump. Keep your elbows locked to your sides and move your body rather than your arms. This helps immensely with even grinds.

-Keep good lighting at your grinder.

-Letting your belt hang off the plunge side of the knife helps keep a nice plunge and help with more even grinding.

-Learn to feel where your bevel is when against the belt and how much you need to adjust to get it where you want it. When starting you grind a hard angle to get to your desired pre-edge thickness and then walk the bevel back towards the spine, getting each angle flat before going to a smaller angle.

Hope this helps! Good luck!
 
What is your belt progression to get to this point? I am a rank beginner so can only share my recent experiences.

There was a belt progression I saw discussed in another post that I am following (VSM 885 Ceramics, followed by Hermes Aluminum Oxide, followed by Trizact Finishing belts, with cork as a last machine step). I start with ceramic VSM 885 50grit and then move to VSM 885 100g. These are very stiff belts. The plunge the create is more square.

I then move to Hermes Aluminum Oxide (AO) 100g and 200g which are much more flexible. I track the belt over the edge of the platen and using these belts, a more curved plunge is created with rounder top.

My problems start again when I move to 3M Trizact A65 and 3M Trizact A45. These are stiffer than the AO belts and I seem to mess up my plunge lines with these stiffer belts. I like what they do on the flats, but I haven't figured them out for plunges yet.
 
AO is not always cheaper! It definitely wasn't for me. I would go through 2-4 80 grit AO belts for one knife when I could have used 1 ceramic for 5-10 knives. And I can get an AO for $2.60 and a ceramic for $5.70. See what I am getting at?

And your grinds will be better and happier.

Huh, I have never had plunge problems with stiff belts..
 
[QUOTE Huh, I have never had plunge problems with stiff belts..[/QUOTE]
Thats why I wish I had stiff belts. The slack belts screw with me too much.
 
It's hard to get good plunges on the Grizzly, because the belt tension is so low the belts wonder from side to side. My platen also came somewhat bent, so I made a steel platen that mounts on top of the original. All that being said, many knifemakers with fancier machines will fine tune the plunge lines with a round file and some sandpaper.
 
SirSpice said:
It's hard to get good plunges on the Grizzly, because the belt tension is so low the belts wonder from side to side. My platen also came somewhat bent, so I made a steel platen that mounts on top of the original. All that being said, many knifemakers with fancier machines will fine tune the plunge lines with a round file and some sandpaper.
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I have never had this problem with the grizzly.

This leads me to another tip. Put a belt on the grinder and then adjust the tracking wheel arm to where it is pretty tight. Then take the belt off and pull the arm out a bit more. After getting the tension right, things have been much better for me.

And as SirSpice mentioned, don't be afraid to use hand tools to fix little things and clean up plunge lines.
 
The VSM belts from pops are a great deal and probably where you want to go with your next order.

I just tried something new last night that might help. I cut a board at around 5 degrees and used it with a tool rest as a guide. Once you get some flats started it's pretty easy to move from there. I was doing a 3/16 machete blade and it was fast and easy. It would help you with your plunge lines. A file guide really makes the plunge lines easier. It's well worth saving for.
 
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