Grinding advice please.

J. Hoffman

J. Hoffman

Joined
Jan 1, 2011
Messages
1,798
I've done just three blades on my new grinder so far, and I can say that each grind has gotten a little bit better than the last one (I've been choosing easier grinds though too). I would really love it if some of you experts could take a look at my grinds and give me any suggestions. I am using a Bubble Jig, and I've learned that I need to keep my eye on the bubble instead of the blade. I've also learned that welding gloves are my friend. Before the gloves I would get half way through a pass on the grinder and the blade would get really hot, and I would flinch or I would hurry up and not get the grind I wanted. I'll show four blades that I have done so far.


1. This is my first knife and was done about 99% with files. The original bevels that I put on by draw-filing were uneven. A quick touch with the slack belt gave me a pretty decent convex grind.
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2. This is my second knife, done completely on my grinder. One side of the grind is nearly perfect, the other side looks horrible. It's a very low bevel and changes height and angles several times. I've tried fixing it with the grinder, to the point that the blade is now very thin. I think this blade will end up being the test material for etching and patinas.
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Bad Grind!
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3. This one is also totally done on the grinder and is a copy of my first knife. The bevels didn't turn out to bad on this one, although one is higher than the other. I have been grinding the bevels and then grinding the flat side flat to even up the bevels. I also need to make sure that I'm not throwing the edge off center.
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4. This is by far my straightest, most even grind yet, but it's also the easiest grind. It's a chisel style grind on a cleaver style knife. I believe it's at 12 degrees, and I'm thinking I should take it to 10 degrees. My hope is to have it be a veggy slicer. All blades are/were 1/8" Aldo 1084. Any help or suggestions would be greatly appreciated. Thanks Jess/Mooseyard
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A sharp new belt will help keep it from getting hot so fast.. and a rubber (or old shoe sole) stick is good for cleaning the belt grit which will help extend that a little bit. Are you using a platen or round contact wheel for your grinds? Maybe its just the picture but the last one looks hollow ground.
 
mgysgthath said:
A sharp new belt will help keep it from getting hot so fast.. and a rubber (or old shoe sole) stick is good for cleaning the belt grit which will help extend that a little bit. Are you using a platen or round contact wheel for your grinds? Maybe its just the picture but the last one looks hollow ground.
Click to expand...

I'm just using a flat platen right now. I'm afraid to try the 8" wheel for hollow grinds.

The other thing I forgot to mention is that I find keeping the grinds straight a lot easier with the Blaze belts I have as apposed to the Gator belts. Maybe it's just me, and I'm imagining things though. I guess three blades isn't enough for me to decide which belts are best. I'll try more of each.
 
What grits are you using?

Sounds like you are trying to use a dull belt if it's getting hot that fast. Are you using the same belt to grind bevels and profile blades? I like to keep one set of belts that only get used for grinding bevels. I use only brand new belts for handles then when my current bevel grinding belt gets dull it becomes my new profiling belt and my handle belt becomes the new bevel belt.

Or maybe you are trying to take off way too much on each pass? It should take quite a few passes to get to the final thickness.

I tend to push pretty hard when grinding but with a fresh belt overheating is rarely an issue. The edge will usually turn yellow but rarely blue and I am done with the pass and into the water bucket before the heat reaches my fingers.
 
I'm using a Blaze 36 for profiling and then a Blaze 80. Then I go onto the Gators I have been using fairly new belts. The chopper didn't turn blue until the final pass and that was with a Gator 45. I just need a lot more practice. I tried using push sticks and it just didn't work well for me. The welding gloves seem to keep my fingers from burning.

Jason, are using ceramic belts for your handles? I thought some one said that AO were best for handles because ceramics built up to quickly. I haven't even thought about grinding handles yet.
 
You should be pleased. Four blades and the grinds looking that good, is a great start. You are correct in that it takes practice, what ever your approach.
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Use the 36's for bevels, especially the early part of the grind. Switch to the 80's when you're 75% done with the bevels.

Toughen your fingers up, or you can't use the handle Mooseyard.:D

Keep the grind lines even all the way up, narrow the tip towards the end of the grind.

Don't spend a lot of time on anyone blade, grind another one, you learn by doing when it comes to grinding.

Have fun, Fred
 
I use the blaze 40 and 120 then 3m 977 in 220 then go to the gator belts and micron belts. I never saw the point in buying different belts for handles since each belt will see at most one or two handles before it's used for grinding bevels.


Honestly, your grinds look pretty good for only having done a few. It just takes practice to get the feel for keeping things perfectly even and smooth. Maybe try easing up on the pressure when you get to the tip as it looks like you are taking just a bit too much off there but otherwise just keep on keepin' on :)
 
Mooseyard:
The heat thing had me trying to rush through each pass of the blade across the belt, and as you know, rushing is the best way to waste time and material. I tried using a push stick but felt I needed to be more "hands-on" somehow. Gloves didn't do it for me either. I also use a bubble jig, and I made grinding guards, but they really only serve as a handle to hold the blade. So, holding the "handle" in one hand I also hold a Popsicle stick with my thumb. The stick lays across the back of the blade. I put my fingers on the Popsicle stick to help guide the blade across the grinder and VOILA! I get the tactual feedback I need, no burnt fingers, no fear of burnt fingers so no rushing, and a better job is done.

I'm using a mighty Sears 2X42, and along with not burning my fingers, I find I am developing a lighter touch as I set the blade to the belt going a thousand miles/hour.

For me the bubble jig is not magical. It is difficult to coordinate the bubble, the blade, and the grinder at the same time. This is where the "light touch" is helpful. Though the blade is starting to touch the belt I am able to correct its position and when everything is in proper alignment I then apply force to belt. A person has to LEARN to use the bubble jig, and it took me about three blades before I felt that I was starting to get my money's worth from it. I've ground about 10-12 blades with it and each blade has been getting better and more consistent.

Learning to use a new grinder is another thing you are dealing with. Your grinds maybe aren't perfect, but they look darn good to me. You're improving with each blade you grind.

- Paul Meske
 
I think you're only issue is patience. ;)

I know that with that shiny new grinder, you want to be knocking out museum quality blades right out of the gate, but it just ain't gonna happen. The grinder WILL cut down on your learning curve, but it's still going to take time. I bought a brand spank'n new variable Burr King in 1996. It was the top of the heap then, much like the TW-90 is now. I had made many knives with files and was just sure I was going to knock a bunch of blades out of the park... I proceeded to ruin a whole lot of steel. A LOT of it.

I heard things like, "You should get the hang of grinding after 5 blades." So I'd go out and profile 5 blades to the exact same shape, then proceed to f them all up. :mad: :o :grumpy: ALL 5 of them.

Looking back, I never had a magic number of blades, things just started to click. And of course I'm still learning with every one.

So my advice, is to stop, take a deep breath (or 20) and just keep on it. You will get to where you're happy with the outcome. I think for 4 blades in, you are quite a long way ahead of the curve. :)
 
NickWheeler said:
So I'd go out and profile 5 blades to the exact same shape, then proceed to f them all up. :mad: :o :grumpy: ALL 5 of them.
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That's actually kind of encouraging, seeing as I am in the same boat - My paring knives are coming out great for ergonomics and edge holding - I've even gotten a couple of orders already, but I haven't made anything I'm willing to etch my mark on.

So, maybe after a few dozen more I can start to complain?
 
Great post Nick.

I hope coming from you, people who are new realize this is hard stuff. I'm new but not brand new and I'm continually surprised how hard it can be. Hours and hours of work and one mistake - your knife sucks. Or you make a little change on the fly and it sucks. Or you do great, but the design sucked. Or your belts sucked. I'm recently learning that my pictures need mock ups before I can validate them, or my knife may suck out of the gate. I'm not really sure why I'm doing this.

EA
 
I use the bubble jig as well. I have noticed that after I get maybe 1/2 of my anticipated bevel, I can ignore the bubble. I get it level at the ricasso/plunge and just use the feel of the bevel on the platen at that point.

Thanks for the popsickle stick suggestion. I have used gloves, and don't like the feel. I will have to give that a try.
 
Thank you all for the encouragement. I knew that the grinder wasn't going to be the magic bullet, and that I was going to have a long learning curve. I guess I was also assuming that if I made a mistake on blade there would be a way for me to fix it, but now I've come to the realization that sometimes you just messed it up beyond repair. I've got more steel, so I'll go back to the grinder and see what else I can screw up...I mean make. :)
 
Dont rush things. If you truly love doing it then just do it. I dont count my blades and I dont worry if its turning out near perfect or another "shop knife" I just enjoy the ride. Quick story - I was making a hidden tang bowie for my son and wanting to try a few things out and about 85% thru it I was so amazed on every thing. I really was doing awesoem work and got so worried about f'ing it up guess what I did! I realized I need to just enjoy the ride and not worry so much about rushing my learning curve and losing the fun factor.
 
I have only 2 small things to add to above good advice:

1) Don't try to remove stock with the Gators, as they don't work well for that task (at least not in my hands.) They do work well for some finishing tasks and they last a long, long time. Also, nearly every single time I start encountering a grinding problem, it eventually ends up being due to using a worn belt. Fresh belts make a huge difference for me, and their importance cannot be understated in my opinion.

2) I use a push stick a lot, but when I want that 'feel' and heat is an issue, I'll just wrap some tape around my thumbs or fingers. This allows me to keep my dexterity in the rest of my hand, and I also don't like the idea of wearing gloves around moving machines.

Good luck!
 
Try different styles of push sticks. Not all push sticks are equal. I sometimes use a 3/4" dowel and cut a shelf at the end. This allows the spine to sit on the shelf and the thumb to rest on the blade. You can feel the heat of the blade but get good stability of the push stick
 
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