[jordansahls]

I have been told that you should use a wheel that is at least six inches in diameter, preferably ten, if your going to do a hollow grind.  My wheel is only three inches in diameter, is it possible to do a hollow grind with this, or am I wasting my time?

[DFogg]

Most smiths flat grind and there are arguments pro and con. Hollow grinding can be done on any diameter wheel, though it is easier with the larger wheels. Sometimes it comes down to working with what you have to work with. I really would recommend flat grinding unless you have a compelling reason to hollow grind.

[CProkopp]

It's a beastly thing to get good at. Mithra knows I've tried. Keeping the bevels consistent when changing wheels, the wheels shrinking as they wear down. Polishing out the grind marks on a concave surface while retaining the shape.
Those stubborn, saintly souls who've mastered it are to be revered! Not Worthy

[DannyB]

Thats a good question Jordan. I want it to know too.  Guys, if everyone does flat grind, why most of you have belt sanders with wheels instead of a regular belt sander. They're  less expensive....right?

[RHGraham]

big and more power, longer belts-cooler grinding, longer belt-life... and flat-grinding the long-way on the wheel.

[beuford]

There's some woodcarving knives sold here in my hometown that have the words 'hollow ground' on them.  Funny, but I make these same style of knives in my spare time for friends and small orders from artists.  they're a bent knife design and as I learned quickly when putting the bend in a thin flat piece of steel the edges on the outside of the radius 'flare' out giving it a 'faux' hollow grind.  Hmmmm, if they were truly hollow ground then I think there would be a heftier price tag on them wouldn't there....

[jordansahls]

Thanks for all of your help, but I decided that I will stick to mastering the flat grind first.  Lets just say that I was playing around with the hollow grind and it didn't work out well.  
   Anyways, instead of starting a new thread I have another problem that I think you guys can help me out with.  I can't for the life of me get a well-defined ricasso on my flat ground blade.  I read up on the grinding technique that Don uses, but I'm still not quite sure how I can really clean up the lines and get a well defined ricasso.  Any ideas and former knowledge would be great, thanks.

[Jesse Frank]

You can make a jig out of 2 pieces of hardened steel bolted together over where you want your plunge line. It's the same thing you use for filing shoulders on a through tang.

[jordansahls]

that sounds interesting, do you have any sketches or pics of the jig?  I'm not quite sure how it looks and works.

[larry harley]

hollowgrinding is much easyr and faster
but id dont cut as well and dont chop worth 2 cents
a nd 3 in is jsut good for doing odd things on handles
haveing said that charles ochs flat grinds on a 3 in wheel
and my dad flat ground on a 10 in rock
none of its wrong as long as when u r done the knife is plumb
harley

[larry harley]

hollowgrinding is much easyr and faster
but id dont cut as well and dont chop worth 2 cents
a nd 3 in is jsut good for doing odd things on handles
haveing said that charles ochs flat grinds on a 3 in wheel
and my dad flat ground on a 10 in rock
none of its wrong as long as when u r done the knife is plumb
harley

[CBENNETT]

ON grinding: One method of grinding is just -a-bout as easy as the others. #1 I hollow grind knifes for work that requires finese--Castrating bulls, caping head around the eyes and lips. These are smaller blades.#2 I flat grind camp knives and kitchen stuff. #3 I will slightly convex grind large forged camp and field knives. I really pull the blades down to where there is a smaller transition from the side of the blade down to the edge.
The idea of different grinds being harder than the others. Without a platform under your blade. The trick to any grind, especially a hollow grind is a notched stick 1/2"X2"X4", with the notch being at the very bottom. With the stick in your hand, simply place the spine of the blade on the notch, with the tang in the other hand. Step up to wheel with your elbows pulled in to your body and lock evey thing down, in this position. Use your hips and shift your weight, slowly from one side to the other, making sure you keep your blade level at all times. Watch your grind line that will be the top of your blade, make full passes on your wheel, when you get to the end(TIP) simply pull out on the tang. Do not pull up, just pull the tang straight away from the wheel, just a very little bit, until you get used to the action that it requires. This is how I do all my grinding, flat, hollow or convex. I don't use a platorm under the blades, just this piece of wood with an notch it. Then switch hands and do the other side.
You could use some cheaper steel to practice on. After some practice this very easy to do.
For the original question: What size wheel to hollow grind on?? I prefer eight inch wheels or bigger to hollow grind. I flat grind on a nine inch reversing disc, or a platen on a BADER. For convex grinds I used a slack-belt sander that I built. I also use this sander quite a bit on handles.

Chuck

This post has been edited by CBENNETT: 14 March 2005 - 06:14 PM

[Al Massey]

Hollow grinding has its place, even in swords- many cut and thrust swords were done this way, albeit with a secondary bevel to keep it from chipping out easilly.
The larger the wheel size, the better to an extent- 8-10" is good.
A key point is not to run your grind right to the edge too much- you need to have some metal left there for final working after heat-treat. If you're not using a jig than do nice, even passes, not putting too much pressure and checking where your line is every couple of passes.
I agree with Larry a hollow-grind does not chop as well as a flat, but when you're talking swords, you have enough blade velocity to overcome much of this and the great stiffness of hollowgrinds gives you an excellent thrusting blade while keeping weight down.