Difficulty of hollow grinding

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AfterTFD

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Oct 28, 2007
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Jarod's recent video and thread got me wondering about something.

How hard is it really to do a good freehand hollow grind?

What kind of learning curve is it? Is this something that can be picked up on within a few blades? A dozen? A hundred? Is there a great difference in skill required between what it takes to do an ok hollow grind and an excellent hollow grind?
 
JTknives said:
are you saying my hollow grinds are just OK :D
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It looked great to me. What I meant by that question was that I was wondering whether hollow grinding was one of those things that one can spend decades trying to master or if it was more simple than that.
 
I think I read somewhere something to the effect of "after 20 or so blades you will start to get the hang of it, after a hundred or so you will look back and wonder why you had so much trouble before". My appologies for not remembering who said/wrote it, but I agree with it. I think years would be more realistic as far as mastering any grind style. I hear even the masters muck up a blade every now and then no matter how many years they have been at it, but I may be wrong on some acount.

Dustin
 
I think it's easier to become a local "expert" than it is to figure out how to do it all and do it WELL.

Just my $0.02.

Oh, and Fitz.... You're welcome ;) :p
 
every time i do a hollow grind i get better at somthing. what i have done for my self is try and understand why thangs happen. like how to get the grind to do what you want because you know whats going on. how to move grind lines where you want by putting presher in certin places. once you are one with the knife you will know what to do. spend some time thinking in your mind how the blade and belt react to each other. imagin putting force in a place and try and think how that will effect the blade.
 
It's not as hard as you would think. Once you have an initial groove established, the blade will want to ride the wheel in that groove. It is just a matter of applying pressure where you want the grind to go, and having the proper wheel size for the grind width. I would suggest a full width grind for the first few, before you try doing one with a grind line below the spine. Just take your time at it. A slower speed on the grinder will help as you get near the finish. My first one came out fine, and it was ground as a line grind. Patience goes a long way, and you just need to get in there, and try it. Here's one I did a few years after the first. 5" blade.
pennyknife402_640x480.jpg
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BigJimSlade said:
I think I read somewhere something to the effect of "after 20 or so blades you will start to get the hang of it, after a hundred or so you will look back and wonder why you had so much trouble before".

Dustin
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bout the same as can be said about flat grinding

its all about working at it and having your far share of mess ups




then making some more later too :D
i like the oops i ground all the way through the blade one
 
How much does blade length effect the difficulty?

What about width from edge to spine? Are wider or narrower blades easier to hollow grind, assuming equal thickness?
 
AfterTFD said:
How much does blade length effect the difficulty?

What about width from edge to spine? Are wider or narrower blades easier to hollow grind, assuming equal thickness?
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If you are working on say a sword length, just hold between your hands the maximum amount of the blade you feel comfortable hollow grinding, when you are done on one section move onto the next, when you have made it to the tip take a few long sweeping passes to blend it all in nicely.
 
I find that I [over]analyze the process for so long -without actually trying to do it- that I create mental blocks for myself to overcome. When I approach the task by just jumping in and swimming, I can usually find the current and learn to swim with it, rather than against it. If I draw myself a a 'mental map' of what I expect it takes to do something, I'm usually frustrated until I see someone else do it and break the bad habits I learned by making things more difficult than they really are!
The best advice a neophyte like myself could ever offer is to find a way to get to someone else -a true master of the technique, if possible- and watch and learn. In regard to the question of this thread, I learned more watching Jim Siska grind for 20 minutes than I did in a year of reading, asking questions, failing in front of the grinder, watching videos, etc.

How much does blade length effect difficulty? Wider or narrower? Not much, once you figure out what it is you're supposed to be doing in the first place! Keep at it!
 
One thing that folks have failed to mention...is belts and there intended purpose, as much as a maker has to practice he also has to develop a system. Something I was told and have read is to "Use belts like they are free".

I just hit about 1300 knives this week in 2.5 years, long, short, tall, narrow, tanto's, spear point's, drop points, carbon steel, stainless steel, damascus, ground soft, ground hard.

I still have troubles at times, but at this point in the game I can usually fix my problems before they qualify the knife as a bench queen! Confidence does have a lot to do with it, if you make it harder then it already is you will continue to struggle.

One thing about grinding as with anything there is a time and place for everything, some days I can tell its not the day to grind and now I know to go do something else.

I do grind 90% of my knives in the post HT, I have found that you work with the knife once vs grinding then HTing then regrinding trying to find the groove you once had with that particular knife.

Also if you seem to hit a plateau in your knife making order some high end materials that will cost you dearly should you mess them up, make something that is levels above your current state you should come away a better maker with a new level of expertise? or you mess it up and come away with the knowledge of how it happen?

Anyways use fresh belts and the right belt for the job.
Spencer
 
From the standpoint of a complete newb, I've "made" two full knives, the first a 5" hollow ground EDC built in the shop of a knifemaker with him looking over my shoulder. Turned out pretty good with even grind lines and he didn't have to fix anything for me. My second knife was a flat ground 10" chef's knife made in my wood shop on a cheapie disc grinder. Turned out pretty good as well with only one noticable mistake that I had to fix.

All that said, I'm a woodworker so I'm familiar with what happens when you remove stock, but it's all about patience and paying attention to what's happening. It's not HARD, it's just different so it takes a while to get the hang of the movements. Some folks are wired "right" and pick it up quickly, some don't have the capacity and never get it, most of us are somewhere in between.

J-
 
Free handing on the wheel to me is much easier than flat grinding. Always use good belts like Spencer said. Also I find that a variable speed controller makes a big difference. I have reached the point where I can usually see the problem starting and can make adjustments before I get in trouble. But if you start having problems don't be scared to put it down for a while and try later. I don't really think consciously about things as much as I "feel" what's going on with the wheel. You have to get the feel of the wheel against the blade and use that to sculpt your blade. My $0.02.
-John
 
My practice hollow ground knives all started out a little over sized so if I messed up I could fix them with a file as a flat ground. Of course I have always done everything the hard way.
 
Barker said:
You have to get the feel of the wheel against the blade and use that to sculpt your blade. My $0.02.
-John
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I think it is the same way with the platen also, or slack belt. Though I am honestly not sure how much of that is truth instead of BS pure luck hehe.
 
Imho, I Believe That The Hollow Grind Is Much Easier To Control.
The Grind Lines Are Bolder & More Accurate.
The Ricasso Is Much Easier To Master On A Wheel As Opposed To A Flat Platen.
The Hollow Grind Sucks For A Hand Rubbed Finish & It Isnt As Strong As The Flat Grind, But Is Sure Is Much More Pleasing To Perform.
 
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