Is a hollow grind possible without belt grinder?

J

JZknives

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Feb 7, 2013
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I was reading one of my knife making books last night (the razor edge knife sharpening) and it described a device that makes hollow grinds without a belt grinder. Problem is the drawings and text dont really explain how it is operated. Its basically a bench grinder on a plank that has a hinge on it.

Does anybody have more information on this device ?

Or even better have methods of achieving a hollow grind without having to drop a grand on a belt grinder?
 
I did hollow grinds on my first couple of knives many years ago with a 6" bench grinder... and you can tell by looking at them. It's not the best way to go about it, by a long shot, and the results may not be what you have in mind...especially if the grinding wheel comes apart at speed. There are potential safety issues when using stone wheels that you should be aware of, especially if you use jigs or fixtures of any type to hold the blade. I can say from experience that it is possible, but that dosen't mean it's a good idea by any means...
 
This is useless response :-) but Nathan the Machinist reliably does hollow grinds without
a belt grinder. Unfortunately the CNC mill he uses costs a wee bit more than a grand...
 
You can use an expanding drum sander. It's basically a belt grinder with a contact wheel and a very short belt. The belts will wear rather quickly, but you can do an excellent job with one bolted to a bench grinder.
 
Bill DeShivs said:
You can use an expanding drum sander. It's basically a belt grinder with a contact wheel and a very short belt. The belts will wear rather quickly, but you can do an excellent job with one bolted to a bench grinder.
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do you have a link to a machine?
 
I bought a curved platen from Nathan the Machinist. It produces a 36" cirle arc. He makes them up to 72" I believe. I normaly use a 10" wheel. Frank
 
Honestly- I don't know what to say!
How would you do a hollow grind with a round file?
 
Hollow grinding without a belt running on a contact wheel is kind of like driving without a car.

(( rules violation ))
 
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Grease said:
Steady hands and a solid vice would let you do it with a round file.
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This is the same guy who has made a couple of knives and was expounding the other day about having just discovered profiling with an angle grinder

http://www.bladeforums.com/forums/showthread.php/1050224-Why-didn-t-you-guys-tell-me-!

The tool that will allow you to do a hollow without any sort of grinder is a Japanese Sen

http://www.google.com/imgres?imgurl=http://i111.photobucket.com/albums/n130/tobycrocker/100_0001.jpg&imgrefurl=http://www.britishblades.com/forums/showthread.php?54853-Japanese-Sen-scraper-tool&h=480&w=640&sz=55&tbnid=YxRClh4krRyTuM:&tbnh=90&tbnw=120&zoom=1&usg=__TUFupqshfCERLBMl5VUTjGw2pC0=&docid=I49_xddhDrSEnM&sa=X&ei=QG5OUeGoFZK64AOW9YCYDA&ved=0CFsQ9QEwBQ&dur=7016

A hardened steel scraper, if it is made with a curve you can use it to produce hollow grind

-Page
 
Grease commented somewhere else and I quote.

"(I offer my knowledge gained from 1.5 years working in WA's biggest used book store)"

Need I say anything else? I do believe he's said it all right there. I admit to taking it out of context but I just can't help myself.

****seriously rolling my eyes here****

My bad.

Syn
 
You could clamp the stock in a vise and use a hand held grinder, but I don't think you'd be excited about the results if you've ever used anything better...
Andy
 
Hollow grinding is just another of the many good reasons to get a real grinder. Put that time you'd spend trying to hand hollow grind a knife, into building a belt grinder.
 
There are rights of passage that ALL newly minted knifemakers to-be go through. Some of those are simply more expensive then others (wasting $$$ on cheap, inadequate tools, perhaps dangerous even, comes to mind). Some are in the realm of life-threatening. Some are just physically painful.

Faithfully accepting the need for the BEST safety eyewear you can afford might top my list followed closely by respiratory protection...............

Not bothering to read up, study and listen hard to much more experienced professionals who freely share information, much less arguing with them could be a right of passage also. There are lots more but these are the ones that pop into My head without any effort.

I thank all the people who take time to share so freely in forums like this one..........

Syn
 
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So my first hollow ground hunter was done on a OLD HEAVY table saw, that had the blade removed and a stone mounted, I couldnt tell the speeds, I believe there was step pulleys in the back, there was a guide that mounted on the table and you would essentially walk the grind up. My understanding was it was used to do post heat treat grinding on small folder blades, that were too tough to grind freehand on the belt grinders. IMO a 2x72 of some sorts is an essintial for knifemaking.
Greg
 
elementfe said:
You could clamp the stock in a vise and use a hand held grinder, but I don't think you'd be excited about the results if you've ever used anything better...
Andy
Click to expand...

After reading the last thread about angle grinders, as well as seeing the pictures of the injuries and fatalities, I think you would be well advised to skip the angle grinder, completely, for anything, forever. Not only will you not be able to achieve any sort of decent hollow grind, but the risk is just too high. Personally I would suggest building a belt grinder if you don't have the coin to buy one. I built a modified NWGS with flat platen, and 1 hp motor for under 500 bucks. Will eventually upgrade to more power, but for the cost it works awesome. Their really is no comparison at all between it and my 1x30
 
I made my first knife on a bench grinder during the nightshift and learned from it that yes it can be done, but the result was rough. It was the flame that lit the torch on knifemaking for me. Then I made phone calls and long yellow page searches (the internet and PC world was not established back then) and bought myself a Wilton square wheel grinder that I still use today. The difference between the bench grinder and belt grinder was like day and night.
 
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