Are you fed up with horribly blunt knifes
and lack the skills to use a wet stone?
Today I’ll show you how you can use your
3D printer to get your knifes as sharp as
they have never been before.
Guten Tag everybody, I’m Stefan and welcome
to CNC Kitchen!
This video is sponsored in part by Skillshare.
There is a reason why this channel is called
CNC Kitchen and today we’ll explore a direction
which is a bit more kitchen related.
So I cook a lot and just like in my workshop,
in order to do a proper job, you need proper
tools.
Working with sharp knifes is something I myself
find so satisfying.
Watching the blade dig through a tomato under
its own weight is just awesome.
A proper knife enables you to work more precisely,
faster and even is safer and more predictable.
Unfortunately, knifes get dull over time and
at some point there is no way around re-sharpening.
I bought a half decent wet stone many years
ago but I just lack the skill and patience
to get a consistent blade angle during the
use of it probably just as I’m also physically
uncapable to play shooter games with a gamepad.
What I do not lack is a 3D printer and so
I designed a knife sharpening tool more than
3 years ago which is quite popular on Thingiverse
and has been downloaded more than 10000 times
already.
It does take quite affordable standardized
wet stones that you can get in many different
grids almost anywhere online.
The guide on my tool then helps you to first
adjust the precise sharpening angle you want
and keeps it very constant over all steps.
Yes, I know that you can purchase similar
jigs for $20 online but on the one hand they
are often garbage and on the other hand why
not print something useful for once?
By the way – if you like my videos then
why not subscribe to the channel to not miss
any upcoming videos?
It’s highly appreciated!
No food has been wasted during the creation
of this clip.
So the old design did work and I sharpened
many knifes and even lawnmower blades with
it over the years.
In the preparation of this video I assessed
it once again and improved it in a couple
of ways to make it more precise and better
to use.
Since filming this video, I actually already
made another revision to make it even better.
If you want to make one yourself, there are
links to the CAD file and STLs down in the
description.
Since I created the initial design in another
CAD software, this was also quite a good lesson
for me in how assemblies are handled in Fusion
360.
Most notably the new design features a longer
handpiece with a finger guard which makes
it easier to hold and protects you a bit from
cutting yourself.
The blade is held in position by magnets.
The old design had the problem that if they
weren’t perfectly stuck in their holes,
they could scratch the metal.
I now added pockets from the side in which
you can now slide 10mm diameter disc magnets.
The most important improvement that I actually
included from a remix, is the guide which
makes sure that the wet stone stays at a perfect
angle.
The old one only used a hole which allowed
for some play whereas the new one uses a spherical
bearing which has way less play.
In my case I printed all of the parts in das
Filament PETG which makes the parts in theory
dish washer safe.
PLA would be totally fine for the tool as
well.
Assembly is pretty straight forward and the
only thing you need besides the 3D printed
parts are some 6 and 10mm aluminum rods and
a couple of M3 and M4 bolts and nuts.
For all lovers of the imperial units out there,
you should also be able to get away with 1/4”
and 3/8” round stock.
To make everything more stable on the table
I added these rubber feet which we actually
call “fish eyes” in German.
Kind of creepy, but it does fit.
Before we start with our sharpening work make
sure to dump the stones into some water so
that they can soak a little.
Now take a water resistant marker and paint
the whole edge of your knife.
This will tremendously help you later in judging
if you have removed enough material and can
proceed with a finer grain.
If you stop sharpening too soon the cutting
edge of the knife won’t get touched by the
stone and stay dull.
The stones should fit snuggly in the handle,
if not, just use some tape.
Next, we need to set the sharpening angle
of the blade.
The sharpening angle is usually the angle
between the symmetry line of the blade and
one bevel of the cutting edge.
If you have a knife that is only sharpened
on one side like some Japanese knifes or scissors
for example , then it’s the angle between
the unsharpened side and the bevel.
This depends on the application and material
of your knife.
For standard kitchen knifes 15° is pretty
common.
If you have a sashimi knife it can be around
10°.
For a chopping knife that has to go through
bones the angle can even be 30°.
The smaller the angle, the sharper the blade
but also the less durable it will be.
In my case I chose 15° which is a nice compromise
between durability and sharpness.
In order to set the angle, I use these angle
guides.
Just place it next to the stone and adjust
the guide until they are parallel.
The knife itself is held in position by the
magnets.
Make sure that it is centered and the cutting
edge is more or less perpendicular to the
sharpening stone.
The stop prevents the knife from rotating.
Also be sure that you slide the blade sufficiently
far down so that it’s stable.
Often you have to spend a bit to get a blade
made out of proper steel but this actually
is a 10 bucks IKEA VÖRDA knife which seriously
has been serving me so well over years.
Really pick one up for yourself when you’re
at IKEA next time, you won’t be disappointed.
We start with our coarsest grid and this was
in my case 180 for a really dull knife.
Wet the stone and start sharpening.
Don’t add a lot of pressure, there will
still be some patience involved in the process.
Proceed with sharpening as long as you can
still see a bit of the black marker on the
edge.
When you have reached the edge, perform the
same on the other side.
For the first grind this can take quite a
bit.
Next, we go successively though the other
grids.
I used 180, 400, 1500 and 3000 grid for this
blade.
Always make sure that the stone is properly
wet and remove the residues only after you
have finished a side because the particles
are almost acting like lapping paste.
The finer grids only need a minute or two
until you’re done.
To be totally save you can again use the black
marker trick.
For the last step with the 3000-grid stone
I even use sharpening oil to get the best
results, but just see how it works for yourself.
At this point I polish the knife on a piece
of leather with some polishing paste added
to it.
And now we’re all set!
With this method the knife edge is just perfect
every time.
The blade should be sharper than it ever was.
Just watch how it goes thorough vegetables
and performs in the infamous paper test!
Now with your perfectly sharp tool, why not
learn how to properly use it.
Check out the Knife Skills class with Elena
Karp that can be found on Skillshare, who
is todays sponsor.
Skillshare is an online learning community
for creators with more than 25000 classes
focused on design and business but where you
even find courses on cooking or how to make
the perfect espresso.
A premium membership gives you unlimited access
and with less than $10 a month for an annual
subscription, is super affordable.
The first 500 who use the link in the description
will get a 2 months free trial.
So check it out and join the more than 7 million
creators who are already learning with Skillshare!
Thank you very much for watching.
I hope you enjoyed todays project video.
If so, then hit the like button and make sure
you’re subscribed.
If you want to support the channel consider
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Also take a look at my other on 3D printing
science videos I already made in the past.
I hope to have you around in the next one,
auf wiedersehen and good bye.
