Ionut's Small Knife Jig

[Ken S]

Good job, Herman.  One knife doesn't tell the whole story, but it certainly raises some questions about interesting possibilities.  I can see how your jig might be faster for someone sharpening  lot of knives, no resetting for each knife.

Thanks for the post.

Ken

[Herman Trivilino]

That is one benefit.  The other I did the same thing with a pair of pairing knives.  I first ground them both with the grindstone coarse because I was changing the bevel angle, then prepared the grindstone fine and finished both.  No need to remount them in jigs!

[Herman Trivilino]

From another thread ...

Herman, I understand you are aluminumizing your small knife jig. I know is too late but another option maybe better one would be to use UHMW polyethylene to build the platform. It is easily workable, does not clog grind stones if you plan use grind it, it is impervious to water and the best part as I see it is the fact that is very low friction, the blades would slide very easily on it. I believe a 3/8" thickness would provide enough rigidity but it can be even thicker.

It's never too late to try a good idea for a prototype.  The aluminum I have is not thick enough and is therefore not rigid enough.  I was thinking of laminating it to the wooden base, but I like your idea better. 

Where could I get the very small quantity I need?  I take it this is something not readily available in hardware stores or home centers.

The issue is raising the platform high enough above the base of the scissors jig so that the knife handles don't hit it or the US.

Another issue is, as you mentioned, friction.  I found that the wooden surface was just not slippery enough even after waxing and oiling it.  I didn't try grease.   

[Rob]

Don't forget that in inventing the electric light bulb, he failed with the first over 1000 prototypes. He was known to have said "all I've done is find another way it doesn't work" which means I'm closer to my goal.

What a fabulous attitude to never giving up....I've always really liked that epithet.

[ionut]

Hi Herman,

I know Lee Valley has a pack of small pieces different sizes and thicknesses, you will have to check to see if any of them would fit. Last time I got a bunch of 1/4 " and a much thicker than needed one.  If I remember correctly they have bigger pieces sold individually, check their site. There is another company that caries large sheets and different thicknesses of it you can really find it there, It is called Industrial Plastics but I am not sure if you have one close to your place. Unfortunately the hardware stores not only don't carry something like this but if you ask them about it they have no clue what are you talking about, at least that was my experience. Let me know if you can find it close to you anywhere, if not I will stop one day at the store close by and will get a piece for you and send it by mail.
I think a 3/8 thickness would be enough to clear most of the handles but you can always go thicker.

All the best,
Ionut

[Rob]

Could you not switch to tin instead?  You could cut up a thin shim of beer can or similar and laminate wood with it. To fix it, superglue would work as long as its the industrial stuff.

[Ken S]

Ionut's recommendation of Lee Valley is a very good one.  Lee Valley is a very reputable place and has some interesting and unusual things as well as the standard fare.  (They often offer special closeouts at very nice prices.)  I have been a very satisfied customer for many years.   About once a quarter, they advertise free shipping for orders over forty dollars US.

Ken

[Herman Trivilino]

A note on the length of the jig's platform.  As I've stated before, one of the variables involved in the design of this jig is the platform length.  If the platform is too short you won't be able to grind at the smaller edge angles desired for some knives or tools.  On the other hand, if the platform is too long you'll have the grinding edge too far away from the operator for comfort.  So, we want to keep the jig as short as we can and still be able to grind at edge angles as small as, say 10^o.

Thickness of the platform is therefore a factor because the thicker the platform, the longer the jig needs to be.  And for a jig designed to grind down to angles as small as 10^o, every time you add a millimeter of thickness to the platform you have to add nearly 6 mm to it's length.

So we want the platform as thin as we can get it, but not so thin that knife handles hit the US or the scissors jig base.  And, as Rob noted, of a sufficiently rigid material so that it doesn't flex.

[Rob]

Is that why aluminium then....rigidity for a thinner substrate than wood?

[Herman Trivilino]

I think a 3/8 thickness would be enough to clear most of the handles but you can always go thicker.

I think that would be about right, Ionut.  Thanks for your offer.  I'll ask around and see where I can go to buy some.  I live and work in the greater Houston area, which is a major industrial area.  The stuff's got to be around here somewhere.

[Herman Trivilino]

Could you not switch to tin instead?  You could cut up a thin shim of beer can or similar and laminate wood with it. To fix it, superglue would work as long as its the industrial stuff.

Uhhh ... Rob, I believe that even on your side of the pond they make beer cans out of aluminum!  The aluminum I have is about 1/8" thick.  But if you could find a way to successfully laminate a thinner piece to the wood you wouldn't have to worry about grinding the bevel on the aluminum.

[Herman Trivilino]

Is that why aluminium then....rigidity for a thinner substrate than wood?

Well, that would be a factor, but I hadn't considered it.  The problem with wood is it's not very slippery and it's not water proof.  If I could get a slab of aluminum about 3/8" or 1/2" I'd be very happy.  So, availability of materials is another factor.

Ionut's idea for the material is a good one.

[Rob]

Ah got it....metal because of water resistance and slippery

[Rob]

Congrats Hero Herman :-)

[Rob]

You and Ken will be giving Jeff a run on the post count soon.

What's after hero......galaxy class?