3D Printed Knife Sharpening Tool Makes The Job Easy

A sharp knife is a joy to use, but many of us are guilty of buying the cheapest kitchen tools available and rarely maintaining them. Keeping knives sharp is key to working with them both safely and effectively, but to sharpen by hand requires patience and skill. [CNC Kitchen] instead decided to use technology to get around the problem, designing a 3D-printed tool to make the job easy (Youtube video, embedded below).

The knife sharpener is a straightforward build, requiring a few simple 3D printed parts in combination with some nuts, bolts, and aluminum rods. It’s designed to use commonly sized whetstones, which makes procurement easy. The design has undergone refinement over the years, with [CNC Kitchen] adding pockets for the magnets and a spherical bearing which reduces slop in the movement.

[CNC Kitchen] reports that the tool works wonderfully, allowing even a novice to sharpen knives well. Parts are available on Thingiverse for those who wish to print their own. If however, you insist on doing things the old-fashioned way, you can get an electronic coach to help improve your technique. Video after the break.

19 thoughts on “3D Printed Knife Sharpening Tool Makes The Job Easy

  1. I may not be the sharpest knife in the drawer, but I think this is a fairly elegant solution compared to many commercial offerings. (I strictly hand sharpen…. been doing it for a long time, have the muscle memory, and though the edges arn’t perfect, they are still close enough to surgical sharp for practical purposes)

    1. I agree with you, this seems to be a really elegant and simple solution to a basic problem. I will also stick to hand sharpening, but if I ever needed to use a sharpening tool for some reason, I’d probabky look in this project’s direction.

      1. I have enough of sharpening, it tooks space, time, ritual bla bla…
        We live in a industrial part of the world where time is a ressource.
        I am looking for a bunch of cheap knifes for use and throw away.
        The fastest and sharpest edge i get is from a hand drill with a sanding pad attachement with 320 up to 1200 grit and then pure bristol cartboard without polishing compound. I get a tip sharpness. Simply lightly tip your skin with the blade and you have a cut. But it tooks time.

  2. I might upload my design to thingiverse. This one looks really nice but uses a lot of plastic and two rod diameters. It’s harder to replicate and once you by the parts probably not that much cheaper than the $20 version you can buy on ebay.

    1. It definitely takes a little practice to sharpen by hand; I’ve been doing it for about a decade myself.
      What I don’t like about systems like this is that it’s nearly impossible to get the geometry right across the blade; you’d have to calculate the angle through the flat of the blade, then readjust for the tip, and make sure you’re grinding evenly through that transition to maintain the edge profile.
      By the time you do all that, you might as well have done it by hand.

  3. How is this to be resized for japanese katana swords?
    Point in case being my wife(!) does Iaidò, while riding(!!) our mongolian ponys.

    2 out of 3 metal swords she owns (beside 3 wooden bokken) are not sharpened.
    But about that sharp one I am on my way to nightmares for when it comes to maintenance of its sharpness…

    (Don’t fear: also the dull ones are enough for cleanly cutting apart soda cans, when appropriatedly wielded. Ok, so better fear =:-o )

    1. I would not let my swords get within a mile of this monstrosity. Swords need a bevel grind so that the edge can take a beating get someone who knows what they are doing to sharpen them and stay away from this crutch.

  4. The usual solution to this are rod sharpeners. You have these two 10″ or so ceramic rods sticking out of a base at angles. All you have to do to get a controlled symmetrical edge is hold the knife straight as you run it along each rod. Rod sharpeners usually pack into the base and so are more compact than you’d think. The advantage here is probably speed with the ability to use diamond stones and a larger cut area, so better for knives starting dull.

    1. the rods are for honing an already sharpened knife, bringing its edge back to true. there are rod sharpeners made by lansky & spyderco (and I am sure some other manufacturers, not to mention the Chinese manufacturers who steal designs for both knives & sharpeners using impossibly cheap steel and plastic instead of g-10 or other appropriate materials).

      the sharpener shown here appears to be a knockoff of the wicked edge sharpening system. the cheapest I recall is $250.

  5. For a guided material removal, their technique is horribly variable.

    Most people using such a device, don’t bother with a primary then secondary bevel, let alone a tertiary micro-bevel. My nephew got one of the commercial ones. Nice for establishing the primary bevel the first time, even the secondary bevel. He was surprised that I can use a planed block of maple with some Autosol metal polish and get a better edge faster by hand.

  6. No need to learn how to hand sharpen a knife like a stone age man anymore. We have modern tools now, but even this 3d print is a little overkill and it seems to me like a “because I can” print. There are cheap knife sharpeners around in every 1Currency shop that do what they are made for, sharpen your knife.


    You pull it through 3 times and the knife is sharp again. I do it once every few weeks and all is good. Best is not to put the knifes in the dish washer too often because they get a bit less sharp in it every time.

  7. You know most knives only ever need a stropping to restore their edges. That is unless you are a moron who has made it their goal to chip their edges in which case you should take it to a pro who knows what they are doing. Source of knowledge better part of a decade becoming a bladesmith and apprenticing to other very well established bladesmiths

  8. some of us have beloveds who take it as a mission not to clean & put away knives after use; they chuck them against other steels in the dishwasher.
    I found it far simplest to grip the blade in a toolmakers clamp- use the threaded bar against the bench to maintain the angle; easy to flip over. Modify the threaded bar lengths to give an even angle. use a 1mm shim sheet to give the lift for the cutting edge.

    600 & 100-1200 grit diamond does the job quickly.

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