# Jointer Knife Sharpening Jig



## Stevedore (Dec 28, 2011)

I decided that I finally needed a jig for sharpening my jointer knives. I always enjoy seeing other's various jigs posted here, so I thought I'd share my little project. 

I liked Brian Grella's design on his Garage Woodworks site, so I copied it, with a few minor changes. I plan to use it with wet-or-dry sandpaper on a polished granite tile. 

The body is made of cherry, the adjusting bar is maple. I used epoxy to glue the 2 body pieces together.

I used a simple threaded insert and a thumbscrew for the height/angle adjusting bar, as you can see in the photos. I also added a small strip of brass in the square hole for the adjusting bar, so that the thumbscrew won't dig in to the wood bar. It seems to clamp very tightly; I don't expect it to move during use.

For the roller, I used a replacement shower door roller from a package of 4 that I bought at Home Depot. The nylon roller may wear faster than the small ball bearing used on the jig on the Garage Woodworks site, but it's cheap & easy enough to replace if it becomes necessary.

And finally, I used couple of fender washers & screws to hold the jointer knife in place. I bent a small section on the edge of each washer, which contacts the center of the knife when tightened down. Seems to work OK so far.


Pics:


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## Al B Thayer (Dec 10, 2011)

Good idea but I bet you ware that wheel out in no time. I made one to do both jointer and planer knives. I just hate sending them out. They come back sharp but who knows how much they ground off to get them there.

Al

Nails only hold themselves.


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## Brian T. (Dec 19, 2012)

Because it's rolling, not sliding, I'll guess that the wheel will last for some time. 
How often will you need to do this chore? Measure the diameter and write it on the wall.
My sole concern is that the wheel can pick up grit and transfer that to finer grit papers.


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## Al B Thayer (Dec 10, 2011)

Steve
Have you tried it yet on the sandpaper? Please post after you do. 

Al

Nails only hold themselves.


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## Stevedore (Dec 28, 2011)

I only tried it briefly to get a feel for how it worked. I first need to rig up something to grind a fresh face on the knives I'm using for a test case. They were in the jointer when I got it, and they look as if the previous owner tried grinding them freehand. I'm hoping to kludge something up in the next few days.


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## Al B Thayer (Dec 10, 2011)

Stevedore said:


> I only tried it briefly to get a feel for how it worked. I first need to rig up something to grind a fresh face on the knives I'm using for a test case. They were in the jointer when I got it, and they look as if the previous owner tried grinding them freehand. I'm hoping to kludge something up in the next few days.


I would believe with a heaver grit you should be able to clean them up. I have a fixture I use plate glass and Stikit sand paper on. Your going to find your fixture is going to be far more accurate than the way they have been sharpened and your going to have to do your grinding in the fixture. Because anything you try to use otherwise will be so far off what your fixture is going to give you. Welcome to super sharp. 

I would encourage you to get the blades set in the fixture as close to the same angle they are now. Make a few strokes and see how close you are to hitting across the entire edge. Adjust it till your working the cutting edge. Get it even from one end to the other. You don't have to do the whole face the first time. It will work out each time you sharpen. 









This is my fixture. It slides side to side. I just advance the plate under the blade as the paper breaks down. 

Al

Nails only hold themselves.


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## Brian T. (Dec 19, 2012)

Before you start, wipe the bevels with black felt marker = you will know in an instant where the metal is coming off.
Without seeing the blades edge on in a very bright light, I won't suggest a grit size.
Just gigantic carving tools, that's all.


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## Al B Thayer (Dec 10, 2011)

Robson Valley said:


> Before you start, wipe the bevels with black felt marker = you will know in an instant where the metal is coming off.
> Without seeing the blades edge on in a very bright light, I won't suggest a grit size.
> Just gigantic carving tools, that's all.


+1

Al

Nails only hold themselves.


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## Pirate (Jul 23, 2009)

I hone ny planner knives with a shopmade jig. Just a piece of hardwood, with 2 opposing angled slots, with set screws to hold knives. Hone 2 at a time. Works good.


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## Al B Thayer (Dec 10, 2011)

Pirate said:


> I hone ny planner knives with a shopmade jig. Just a piece of hardwood, with 2 opposing angled slots, with set screws to hold knives. Hone 2 at a time. Works good.


I tried that method but couldn't get enough accuracy. Besides I have a 3 knife planer and jointer.

Al

Nails only hold themselves.


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## Pirate (Jul 23, 2009)

Al B Thayer said:


> I tried that method but couldn't get enough accuracy. Besides I have a 3 knife planer and jointer.
> Al
> Nails only hold themselves.


I have a 3 knife planer also. When honing the 3rd knife, I leave one of the first 2 in the fixture, and put mort pressure on the knife needing the honing.
I made a few test cuts, to get the slots right. The set screws hold the knives tight.


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## Al B Thayer (Dec 10, 2011)

Pirate said:


> I have a 3 knife planer also. When honing the 3rd knife, I leave one of the first 2 in the fixture, and put mort pressure on the knife needing the honing.
> I made a few test cuts, to get the slots right. The set screws hold the knives tight.


What happens when it gets loose and the angle changes? Or worse one is different than the other?

Al

Nails only hold themselves.


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## Pirate (Jul 23, 2009)

I found my latest jig for knives. I forgot I changed design last year, and hone 1 knife at a time.
The bottom strip of wood was used to get the angle right, and provide a wear resistance (somewhat) surface. It's Ipe.
Can't remember why I left the strip long.


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## Stevedore (Dec 28, 2011)

*Finally tried it*

I finally got to try my jointer knife jig today, and it worked very well. Life kept getting in the way, but I found some time. (Yard work, son's house needed a new water heater, very ill brother-in-law, etc., etc., etc.)

I originally had planned to make some kind of jig to use to grind a fresh edge on my spare knives before using the jig I originally posted about, but gave up after a bit. I put something together, but it just wasn't working right, so I put the more damaged knives aside, and just used my new jig to sharpen the ones I've been using in my jointer.

The shape & configuration of the jig make it very easy to hold steady & guide back & forth across the wet/dry paper. I used the black marker as suggested above, and it did make it easy to zero in the adjustment of the jig to match the knife angle.

If I'm lucky, I'll get some time tomorrow to reinstall the knives & see how they cut. 

Eventually, I'll probably try something similar for the knives in my Delta "lunchbox" planer. I like Al Thayer's jig, but it's a little too much metalworking for me, so I'll probably try a longer version of the one I just made.


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## Al B Thayer (Dec 10, 2011)

Steve
I like your fixture well enough to maybe build one. I'm going to change mine by building a different way to raise and lower the angle.

Are you doing a micro bevel on your knives? Now that we have a way to sharpen our knives I'm wondering if a micro will improve the cut. I'm sure it will cut down on sharpening time.

Al

Nails only hold themselves.


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## Stevedore (Dec 28, 2011)

Al B Thayer said:


> Steve
> I like your fixture well enough to maybe build one. I'm going to change mine by building a different way to raise and lower the angle.
> 
> Are you doing a micro bevel on your knives? Now that we have a way to sharpen our knives I'm wondering if a micro will improve the cut. I'm sure it will cut down on sharpening time.
> ...


 Al- The angle adjustment is definitely a weak spot in this design. I thought of coming up with some sort of screw adjustment; maybe in version 2? If you come up with something, please post about it!

No micro bevel this time, but I probably will for the next sharpening. Less metal to take off.


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## Al B Thayer (Dec 10, 2011)

Stevedore said:


> Al- The angle adjustment is definitely a weak spot in this design. I thought of coming up with some sort of screw adjustment; maybe in version 2? If you come up with something, please post about it!
> 
> No micro bevel this time, but I probably will for the next sharpening. Less metal to take off.


Is it too wobbly or too much trouble to get dialed in? 

Al

Nails only hold themselves.


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## Stevedore (Dec 28, 2011)

Al B Thayer said:


> Is it too wobbly or too much trouble to get dialed in?
> 
> Al


 The bar is actually a pretty close fit, for wood pieces. Adjusting it just needs a little trial & error, nudging the bar up & down, etc. If I didn't loosen the thumbscrew enough, I couldn't move the bar; loosen it too much & it slipped way off. I'm thinking of adding a small threaded rod coming up out of the base piece, going through a small metal angle piece attached to the adjusting bar. A knurled nut above & below the metal piece would allow small adjustments without letting the thing get way out of whack.

Being an engineer, I'll take every opportunity to overcomplicate this thing, of course!


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## Al B Thayer (Dec 10, 2011)

Stevedore said:


> The bar is actually a pretty close fit, for wood pieces. Adjusting it just needs a little trial & error, nudging the bar up & down, etc. If I didn't loosen the thumbscrew enough, I couldn't move the bar; loosen it too much & it slipped way off. I'm thinking of adding a small threaded rod coming up out of the base piece, going through a small metal angle piece attached to the adjusting bar. A knurled nut above & below the metal piece would allow small adjustments without letting the thing get way out of whack.
> 
> Being an engineer, I'll take every opportunity to overcomplicate this thing, of course!


I think I follow. I'd like to inspire you to continue refining it. I think your on to something . 

I was thinking if it was shaped like an L or boomerang. You wouldn't need such a long adjustment screw.

Al

Nails only hold themselves.









A bit crude.


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