My Sharpening Rig: Inspired by WickedEdge and ApexPro [Pict Heavy]

[Lagrangian]

btw, it seems I got the link wrong for Prof. John Verhoeven's technical report on knife sharpening.

Here's the correct link:
http://www-archive.mse.iastate.edu/...te.edu/static/files/verhoeven/KnifeShExps.pdf

In there, he examins knife edges with an electron microscope. Pretty interesting. He shows that a modern commercial razor has an edge of about 0.4 microns. This is interesting for a couple of reasons. First is its relation to grit size for hones and stropping. Second is that visible light has a wavelength between 0.4-0.7 microns, so the edge may be just smaller than what is (easily) observable with visible light.

 

[Lagrangian]

I finally had time to try out my sharpening rig.

The results are nice, but not perfect because I made some mistakes in my technique:

Actually, the results aren't as good as they appear because I made some mistakes. I found this out when I took some close-up photos of my edge.


First off, after the 600 grit MoldMaster stones from CongressTools.com:

The ruler is in millimeters.

Right now, I don't have an intermediate grit between 600 grit moldmaster stones and 0.5 micron diamond paste. So, things didn't work so well, but it wasn't horrible.

After stropping with 0.5 micron diamond paste on wood:

Oops! As you can see, I got the angle wrong on my stropping, so I polished mostly the back of the bevel away from the cutting edge. Oh well.

Another shot after stropping with different lighting:

Some details:

First, I don't have a USB microscope. I'm taking photos using a point-and-shoot camera (Fuji FinePix F30) with a 10x loupe attached to the front using the amazing-power of double-stick tape. I'll probably never do this again, it was really tricky to set up. Anyway, I mounted the camera using a 1/4" bolt through the eye-hole of my carpenter's square, which I clamped to my sharpening rig. Here's a photo of the setup (without the camera, because I need that to take the picture!):

Okay, so I improved how I attach the stones to the guide-rods. Before I was doing it with rubber bands. I thought a lot about it, but for now, I'm following the "keep it simple stupid" philosophy and using re-usable cable-ties. If you press the little lever, the cable-tie releases. I'm using some plastic film between the stone and the guide rod to prevent scratching.

That's it for now.

If you have any comments/suggestions/critiques, please let me know!

Sincerely,
--Lagrangian

 

[Razorsharp-Travis]

Awesome job lagrangian- Im inspired to build something

 

[singularity35]

Excellent results and a very well thought out and executed design. Bravo!

 

[changeofseasons]

Nice work! There are some stray scratches and a little unevenness in the edge, but that's easily fixable. The loupe is an essential learning tool IMO.

I have just mounted my Wicked Edge on a vacuum base. You might be able to get some ideas from it for your design. If you type in "Wicked Edge vacuum base" into a popular search engine, free build instructions are easy to find.

 

[Komitadjie]

Hey, I'd heard you were planning on making that, CoS! That came out very nicely, I might have to give that a try when mine shows up.

 

[changeofseasons]

Hey, I'd heard you were planning on making that, CoS! That came out very nicely, I might have to give that a try when mine shows up.

Yeah, my WEPS just arrived two days ago. I had the base and the mounting plate ready to go when it arrived, so I just had to bolt it all together. Thankfully all the measurements were correct and it all came together the first time. No hiccups so far and it's pretty solid.

Lagrangian, one thing I've found when working with thin stones is that some of them are flexible. SiC is pretty rigid and probably won't give you problems right away. But AO stones especially in the higher grits will flex enough to mess with your edge. The binder has a lot to do with this. Ceramic is more rigid than resin binder, but they both can bend. At that point, gluing the stones to a blank will be necessary to give proper tensile strength.

 

[rycen]

What is the advantage of the vacuum base or is it just to have the option to position the WE?

 

[Lagrangian]

@changeofseasons:
Sweet! I like how you put WEPS on an adjustible mount.

Yeah, I'm still working on getting a better edge; I think something is wrong with my technique so there is some unevenness in the edge. I think I'm getting some micro-chipping when sharpening.

Thanks for the point that some stones may be flexible. I was thinking they're made of very hard (and therefore rigid) material. But I didn't think that they might have flex, possibly because of the binder. Thanks! I'll have to think about making a blank backing for the stones.

 

[changeofseasons]

What is the advantage of the vacuum base or is it just to have the option to position the WE?

The advantages are a combination of less overall cost, easier portability, and positioning.

 

[Komitadjie]

Very cool, CoS, for a couple reasons!

1: It reduces the size of the assembly down to something you can pack along with you.

2: It means that WEPS are shipping now!

 

[Lagrangian]

In the knife-making section of knifeforums.com, I found this very cool thread about making a file-guide for grinding knives. The filing-guide is by BruceJensky of knifeforums.com

The very same jig could be used for sharepening. I'm posting a link to it here, because it also uses a spherical joint and sliding-rod. It's very similar in concept to many other home-built sharpening rigs, mine included.

This thread is from March 2006! I wish I had found it sooner.

BruceJensky 's filing guide:
http://www.knifeforums.com/forums/showtopic.php?tid/763679/

Sincerely,
--Lagrangian

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"What grit sharpens the mind?"--Zen Sharpening Koan

 

[LeoBarr]

Looking art your creation first of all I think it is great .
Could you glue the stones to aluminium plates sort of EP style but thicker with two/three slots with machine screws that screw into the slots then you could have two bearings for each stone arm similar to the sort of roller bearings found in skateboard wheels but the correct size for the stones rods I am guessing they are 5/16s so the bearings lock off with the machine screws and run on the stone holding rods it the stone plates are aluminium they should not be too hard to both route out the bearing slots and to both drill & tap the holes for the machine screws (the machine screws may stop the centre of the bearings from turning but I do not foresee a problem with that). The stones will glue to the plates with contact adhesive .
If I had your machine this is what I would do since the possible inaccuracies with the Wicked Edge could be the stone holders using the bearings would get rid of wear and increase overall precision.
For a work in progress it has to be potentially one of the best controlled angle sharpeners out there.
I suppose you could just use the WE stone holders if they fit your rods they sell blanks so you could put your own stones on them but I think this is a possible area that could be improved similar to the rod end bearing solution on the Edge Pro which turns it into a precision instrument (thanks Madrookie)!!

 

[LeoBarr]

I like the idea if I am correct of using the threaded rod used to set the angle of the file/stone holder,

 

[Viorel37]

This is my homemade sharpening jig