jigs for grinding?

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knifemaking01

Joined
May 4, 2012
Messages
139
anyone here use them for there hollow grinds??? ive designed one on autocad but would like to know if there used often or weather it is better to learn to do these things by eye and freehand
 
Lots of knife makers use then and lots don't. I keep tweeking my jigs which just push the blade at a slight angle against the platen or loose belt or wheel.
 
Personally, I think it's always better to learn freehand/by eye before learning to depend on a jig... If you ask me, jigs will paint you right into a corner.

I'm not saying that jigs don't have their place, but I would never recommend becoming totally dependent on them. God forbid you have to make a tweak or adjustment to your grind, or do a different kind of grind. A jig will box you in and limit your options in my opinion. Not to mention, I hear about a lot of guys that spend all day long (or longer) making tweaks and adjustments to their jigs just to get the thing where it will turn out a decent blade, and then of course you'll have to start all over every time you change your grinder set up. Then there's the fact that that "perfect" set up is still only good for one type of blade/grind.

It's one of those "teach a man to fish" kind of things......
 
I try to stay away from giving advise as I'm really in no position to give anyone advise, but for me personally, Fred's Bubble Jig really helped me. I do full convex grinds, so I use the Bubble Jig to hog my initial bevels on the platen and then remove it and freehand the blend on the rotary. With his jig, I have the confidence to know that both sides will be completely even. It's worth looking into. After using the Bubble Jig as long as I have now, I know I could walk up to the platen and freehand my grind. But since the Bubble Jig is so easy to use, I see no reason to stop using it, so I continue to do so on every blade.
 
I don't have a ton of experience here, but I find hollow grinding pretty easy the way Gayle Bradley showed me. The knife rest is important.

It is hard for me to describe, but in essence, you don't use a flat bed, you build up the rest to come to a point in the middle of the belt. You can do any kind of hollow grinding without touching or adjusting the knife rest, or "jig".

I guess you might call this "freehanding", but it worked for me the first time I tried it, and hasn't let me down. It's ultra flexible.
 
There is a jig that is so simple people just don't think of it. Watch a video of a professional Japanese, or an old Sheffield grinder grinding the blade. It is screwed to a board.

Cut a piece of oak ( or any strong wood), about 12" longer than the blade, and set the blade blank on it. Drill the tang holes through the wood and run 1/4" bolts through, using wing nuts and washers on the other side. Cut along the belly of the blade about 1/4" from the edge. Leave the wood as handles on each end.

Grip the board in both hands and move it in smooth sweeps as you grind the bevels. This helps a lot with hollow grinds,too.
The excess wood at the edge will grind away with the steel.
I'll try and shoot a photo this weekend.
 
all great very valid points guys, thanks all for your input.... all something to consider

stacy i will check out what your talking about, any photos would be great

thankyou all for your input
 
I've had success with a "sled" type jig. It's just a short piece of angle iron with a bolt at the back to raise and lower the angle. Tricky to use, and a pain in the ass most times, but it does really well on scandi grinds. I've ground full flats with it too, but prefer to do those freehand.
 
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