Grinding even Scandi Bevels?

I

Incahiker

Joined
Oct 2, 2009
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Hello all! I can grind convex knives easily enough just by eyeing it and they come out perfect, but I am wanting to grind in some scandi grind bevels onto a knife I will be making. I have one of the cheapo harbor freight belt grinders, but it works fine for what I need.

Anyways, my question is how do I make it even? Is there any home made jig I can use for this? Do any of you custom makes use jigs or are you just eyeing it when you grind the bevels? How do you custom makers do this?

Thanks!
 
Incahiker said:
Hello all! I can grind convex knives easily enough just by eyeing it and they come out perfect, but I am wanting to grind in some scandi grind bevels onto a knife I will be making. I have one of the cheapo harbor freight belt grinders, but it works fine for what I need.

Anyways, my question is how do I make it even? Is there any home made jig I can use for this? Do any of you custom makes use jigs or are you just eyeing it when you grind the bevels? How do you custom makers do this?

Thanks!
Click to expand...

it is simple, but you need to practice a lot. Just scribe the the center of the edge about 1 mm thick and grind down to that scribe and up to the desired bevel line. Then HT then grind down to the edge, then polish or hand rub.I find the scandi grinds easiest of all...

Emre
 
Very nice, so you are just eyeballing it right?? And you obviously grind against the platen, correct? I thought a jig was needed to give it a perfect look and angle.
 
No need for a jig, if you connect the bevel line to the edge and keep it at the same distance to the edge all along the blade, voila, perfect scandi grind...
Emre
 
Oh, I see what your saying, lol. Some of the simplest things can't be seen until someone points directly at it.
Thanks
 
it is fairly easy. I use blue layout dye, (dykem) scribe your edge like mentioned above, then I take my edge scriber and set it to the depth I want the bevel to go up to, and follow the edge profile from ricasso to tip scribing a line on the side of the blank. The blue layout dye really helps to see how far your grind is going. And, cause you are using the scriber on both sides your marks will be even to start with. Steady hand, good eye, take yer time, it works out. I can take pics later if you want to explain better.
 
I do understand what you are saying, but if you wouldn't mind taking the time to load the pics it would be greatly appreciated. Things usually "Click" better when I see the pictures. Thanks a lot for your help guys, I really appreciate it :thumbup:
 
Make a push stick to push the blade into the grinder at the correct angle. sand the end of it so it's at about 12 degrees.
 
holy shmokes...!! :eek: :eek: :eek:


Guys...keep doing your scandi freehand....makes my jig-ground stuff "high-brow" grinding....LMAO.


Seriously....you shouldn't freehand grind a scandi. You will get "scandi-vex"...LOL....scandi + convex. ie. not perfectly flat.

Especially on a HF hobby belt sander which you can't slow down the speed.



I'm questioning the validity of this thread...and hesitate posting here...but what the heck...I have a knack for sticking my neck out and my foot in my mouth. :p




This is what I use:

DozierGrinder0725-02.jpg


close-up:

DozierGrinder0725-03.jpg
 
Daniel Koster said:
holy shmokes...!! :eek: :eek: :eek:


Guys...keep doing your scandi freehand....makes my jig-ground stuff "high-brow" grinding....LMAO.


Seriously....you shouldn't freehand grind a scandi. You will get "scandi-vex"...LOL....scandi + convex. ie. not perfectly flat.

Especially on a HF hobby belt sander which you can't slow down the speed.



I'm questioning the validity of this thread...and hesitate posting here...but what the heck...I have a knack for sticking my neck out and my foot in my mouth. :p
Click to expand...

Mr Daniel, I want to be sure what are we all doing wrong? How do we have convex grinds with the blades ground on flat platen + hand sanded on a flat block? I really respect you sir, and your knowledge is way higher than me of course, but I really suspect the need of a jig... Don't get me wrong, I don't question your experience or mastery, just I want to understand, could you explain why? I did do some scandi grinds before (not a big fan of them) and sometimes I ended with non-symmetrical grinds which is due to I wasn't able to grind to the center line right, but that was a problem which wasn't too hard to fix. But I didn't find this type of grind challenging, I did fair amounts of reed knives by free hand for example, they can be sharpened with a few strokes on a flat stone, lying on the bevel (which is the main benefit of this grind). The convex maybe happening, but at the hand sanding stage it becomes flat...
Emre
 
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If you are cleaning them up at a stone, then yes, you can get them flat. But I've yet to see a freehand-ground scandi knife that was perfectly flat. Not saying it doesn't exist, I just haven't seen it....and I've seen plenty that are not flat.

Dan
 
Daniel Koster said:
If you are cleaning them up at a stone, then yes, you can get them flat. But I've yet to see a freehand-ground scandi knife that was perfectly flat. Not saying it doesn't exist, I just haven't seen it....and I've seen plenty that are not flat.

Dan
Click to expand...

Thanks Mr Koster, I'll make an adjustable tool rest, do you think that will be enough or do you use a different jig other than you showed above?...
Emre
 
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Thanks a lot Daniel! Is that a home made jig? Is it made out of aluminum? Seems like I could maybe scrounge up something like this. You just keep the knife flat on the jig and then grind the knife until it hits your bevel line?

What about around the curved area at the end of the knife, is there any tips on doing this part?

Thanks
 
Here is the set up I use for edge up grinding, just slide the platen in or out to get the height you require.
MVC-012F.jpg


MVC-013F.jpg


Hollow grinding jig

hollowgrindfinal.jpg
 
This jig will let you grind free hand, so you can fashion the tip, while letting you produce perfect 10 12 or 15 degree bevels on any flat grind.


One maker who has been grinding for close to ten years, e-mailed me that he had cut the time in half, that it took him to do his scandi grinds, by using this jig.

http://www.bladeforums.com/forums/showthread.php?t=681265

Fred

bubble+jig+first+time+009.jpg
 
Daniel Koster said:
If you are cleaning them up at a stone, then yes, you can get them flat. But I've yet to see a freehand-ground scandi knife that was perfectly flat. Not saying it doesn't exist, I just haven't seen it....and I've seen plenty that are not flat.

Dan
Click to expand...

I have not seen it either, nor have I seen any other "flat grind" that was actually flat and still accomplished on a belt machine.
Changing the pitch of the blade you are grinding, by a quarter of a degree is huge and results in a trade off grind, which has will have vex as a suffix.
I like the scadivex designation. Good call:D

Fred
 
Fred.Rowe said:
This jig will let you grind free hand, so you can fashion the tip, while letting you produce perfect 10 12 or 15 degree bevels on any flat grind.


I still suck at free hand, using the right hand is fine swapping over to the left and I bugger the rounded tip every time.
Richard
Click to expand...
 
A tool rest is not a crutch for poor technique. If you have troubles grinding, you'll still have troubles at the tool rest. It does help, but does not remove possibility of error.

You can still 'rotate' the blade upward into the belt and get a 'scandivex' grind by accident.

You can also burn up tips....grind off center...get uneven lines, etc.


Dan
 
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