Help with grinding jig

T

Taximanny

Joined
Jul 27, 2015
Messages
460
I'm trying to make a transition from a filing jig to a 1x30 grinder, so I made this jig.
It will be a jig only used for this pattern. So I would have to make another one for different style blades.
Holding a folder blade seems to be a little more troublesome.
Here is a blade I used the hand filing jig on. I got it the way I want it and chucked it up on my new grinding jig. This is so I can try to get an exact replica.

So the black line is the end of my flat grind.
I want to set this parallel to the bottom of my jig correct?
The black dot below the blade is where I believe I will put a stop pin for the blade to rest on.

Now the plunge line on my knives are set to a slight angle.
Can this not happen while grinding and keeping my end of grind line parallel ?

Any tips????
 
Assuming your flats are parallel (i.e. there is no distal taper), when using your jig with a belt grinder, the grind line will not follow the black line; it will curve with the cutting edge as it goes toward the tip. Another way for me to phrase this is as follows: When using this type of jig, you don't have direct control over the location of the grind line. You set the angle, and grind to the scribed edge lines.

The only way you can get the angled plunge in one step is to mount your blade/jig such that the plunge line is parallel to the belt. Aaron Gough does this.

Take a look at http://www.bladeforums.com/forums/showthread.php/1125493-Grinding-Jigs
 
I use an 'out the front jig' which will do everything you want, pic below:



The blade is fixed by the pivot hold and is supported by a bar under the spine. You can move the support bar to control the angle of the plunge line. Also the baseplate acts as a stop - hitting the platen, you can adjust the position of the baseplate to limit where you can grind and control the position of your plunge.

The beauty of tis design is you can fit the blade in the jig, get the same plunge angle and position on both sides and you can complete grinding both sides without moving the blade.

You do need a tilting work table on your grinder.
 
Yes, that fixture of Mike's will work well with a tilting table. I use two micarta blocks and place the blade in between . The blocks have a screw (bolt ) in each corner for alignment one to another.
 
Ok with that different jig I could get a flat line like I do with a hand filing jig?
That's parallel with the bottom of the jig on my blade style?

So if I grind the way I have it set up now I'll get a grind line like the knife on top of this picture?
 
With Mike's fixture or the micarta blocks you can get either or. It depends how much you tip the table.
Frank.
 
Ok I'm pretty sure I'm understanding...
I'm just gonna have to dive in and get the feel.
I'm gonna start with this jig, if it doesn't work for me I'm gonna change up to a jig where I don't have to move the blade.
 
Taximanny said:
I'm trying to make a transition from a filing jig to a 1x30 grinder, so I made this jig.
It will be a jig only used for this pattern. So I would have to make another one for different style blades.
Holding a folder blade seems to be a little more troublesome.
Here is a blade I used the hand filing jig on. I got it the way I want it and chucked it up on my new grinding jig. This is so I can try to get an exact replica.

So the black line is the end of my flat grind.
I want to set this parallel to the bottom of my jig correct?
The black dot below the blade is where I believe I will put a stop pin for the blade to rest on.

Now the plunge line on my knives are set to a slight angle.
Can this not happen while grinding and keeping my end of grind line parallel ?

Any tips????
Click to expand...

If I understand your question you are wondering if that pictured setup would get you an angled plunge like you have then I believe the answer is no. The plunge is going to be decided by the angle your blade touches the belt.
Unless your table tilts left or right. I assume the bolts are in the jig for front lean?

Im also assuming the jig will be sliding on the work rest and you are not lifting the tang side up.

But with that same jig, tilting the tip down then clamping the blade as the other's pictured above, you'll achieve that angled plunge.
 
Last edited:
You must log in or register to reply here.
Back
Top