Alex, you’re building a Bluetooth version of something woodworkers have had for years. Digital angle gauges. Wixy makes one for $20 USD, with a large lcd display, tare function, & it can be magnetically mounted to your blade. No need to reinvent the wheel if it will be more expensive and require phone connectivity.
Alex French guy and Becky, I have the answer to all your problems, and this will make your gadget totally marketable, and it's simplicity itself...A buzzer (and/or a light) that goes off if you're over 1 or 2 degrees plus or minus on your sharpening angle! A buzzer! All I want is a lousey 1% of every one you sell. Seems reasonable. ;)
Alex, Becky, awesome work! I build DIY electronics for fun, and love watching cooking channels on TH-cam so it really feels like my worlds are colliding :)
put an led on the device that shows green while its in the range you want then turns yellow when its just outside the range and then red when your damaging the blade.
Salut Alex, as said in the other video, I would really ditch the Bluetooth/phone part and replace it with LED on the board directly. When you sharpen you don't want to look anywhere else than at the knife as it could be hazardous. If you put 5 leds to the board you'd have the info right on the blade. It would also make the build cheaper and the battery last longer. And it avoids needing a phone, that also needs a charged battery, be compatible (less of a problem as you are using UART), blablabla. Love your vidéos :)
As Gillermo said, we need a reset angle button to 0 it out on the stone before putting it on the blade, because if it gives you an absolute angle and the stone has 2° offset, you are off.
I would put some kind of LCD to show accuracy like an analogic display, like a guitar tuner. Looking for example like this [ |### ] This LCD should be on top of the device to be able to read it (on the side I mean). BT can be used to change settings of the device with a nice app for blade selection for example.
You, sir, are a true Renaissance man. You are now one of my new favorites. I found you through one of my other favorites, This Old Tony. It gives me a warm fuzzy feeling to know that guys like you and TOT are out there doing your thing. Excellent work.
azdgariarada I was thinking perhaps have a a few settings on the device that when at optimal angle it lights up so you know your have the right angel. I was Army for 14 years so I have a few ideas when it comes to sharp knives.
I've only recently discovered your channel, and it is quickly becoming one of my favourites! Your projects are great, editing is razor sharp, music is lovely and you are just fabulous! Keep up the good work, Alex :)
Consider adding variable haptic feedback proportional to the degree of error, perhaps with high and low sounds to indicate over and under angle variances.
I was literally thinking the exact same thing! In my head there would be a little green LED when you were within the tolerance and have a red one light up when you’re not. And even maybe have an amber one to indicate you’re getting close to being in the red. Could this even be done with a single LED nowadays? Anyway it was film SLRs with an LED exposure indication in the viewfinder that I got the idea from. To me having this haptic feedback would be a good way to train yourself in a tactile way. It would give you instant feedback and allow you to adjust accordingly. Perhaps there could be different feedback for different types of learners? Visual, auditory, read/write (like Alex’s current method)? Just some ideas I had.
Gotta love your approach on those damn useful project! Ça fait pas longtemps que je t'ai découvert et franchement j'adore ta façon d'aborder le story-telling 👌
A tone when you're at the proper angle would give you an idea of the "feel" to achieve the desired angle and train your muscles to maintain a consistent level.
You might try setting the stone itself up at a 17 degree angle and holding the knife perfectly horizontal as you sharpen. Your senses are more naturally attuned to detect and maintain perfect level than a specific degree of angle, so it's easier to hold the knife consistently flat than to hold it at a fixed angle. You can still use the sharpening device you made to check for consistency.
I always found that electric shocks (in this case to your hands) when you fall outside the angle range (ie ± 2 degrees) will give you faster bio-feedback than monitoring a small screen. Subbed after just 30 seconds. You are fun. Nice spirit.
wow you are so concentrated while sharpening! you are awesome! for your little project i think i will take a different route, a smarter but more indipendent little device a small lcd screen for i/o, one button for the initial zeroing, one for increasing the angle, one for decreasing, and one for starting/ending the sharpening session keep working on this project!!!
Hey Alex, one thing to note about using a whetstone, especially Japanese waterstones, is that they tend to start turning concave as you use them. There's some debate in knife circles whether its enough to just use the nagura (cleaning) stone regularly, or whether you have to use a full flattening stone to completely flatten it at some point. Some would even go as far as to flatten their stone after or before every use. I'm more of the camp that using a nagura stone is enough and that the stone itself doesn't need to be perfectly flat to get good results. That means, however, that my sharpening angle, relative to perfectly flat, is going to change between sharpening sessions. Unfortunately, those cardboard angle guides are more likely to give you a more adaptive result becuase they tell you the angle relative to the current shape of your stone, whereas the arduino device always assumes a perfectly flat surface. I'd actually recommend just learning by feel. Muscle memory will eventually take care of the rest.
@Becky You are really cool for makin' this, Keep on being freakin' awesome! @Alex I've got so much respect for you trying out new things the way you do!
You should make the output from the phone auditory! That way you won’t have to look but you can hear if you’re doing a sharp job. For example: maybe the angle of attack can be related to a certain pitch. Higher angle, higher pitch and the other way around. I love your projects and videos! Keep ‘em coming, I’m curious about the development of this tool :)
Wow, that's pretty high tech. For me, personally, I put a convex angle all on my knives (they aren't kitchen knives, though). With a convex edge, keeping a consistent angle doesn't matter quite as much. Great video! God bless!
Will K Same here Will even on kitchen knives. Holding a precise fine angle maybe makes them incrementally sharper but how sharp is sharp. I can shave frog fuzz with a convex angle and it makes the edge stronger too.
To add a bit to Will's answer, Alex here is sharpening on a whetstone. The material will not deform in any way during the sharpening process, and so he is left with an edge that turns out flat. Well, in theory... more on that in a moment. When you want a convex edge, you sharpen on a medium that isn't as firm (e.g. a leather strop, or a mousepad with a piece of sandpaper on top.) The end result is that your edge is curved outward slightly, and tends to be a bit stronger due to the extra material backing it up. It's difficult to obtain the angles desired in most kitchen knives, though, and though Will suggests angles matter less, they are still plenty important, and are augmented by pressure now being a concern. Thing is, when freehand sharpening on a whetstone like Alex here, you can't maintain perfect angles (as is the point of this video) and so you actually end up with a sort of convex edge yourself; many flat angles of different degrees creating a slight curve.
Convex sharpening, especially on a wetstone, needs a lot of experience but indeed, it holds the sharpness much longer and is easyer to refresh with the steel rod. I used this technique even for my Damaskus knifes before I changed to Windmühlen Messer (Robert Herder). They use a historic thin blade technology, and it doesn't matter of 17, 25 or 30'
I was typing Lansky just as you said it lol. But this method is truly genius. the user provides their own stone. this device could have a stroke counter; its very easy to space out and lose count on particularly dull blades as you spend a long time sharpening them. there are no parts, screws, rails or pins that would get lost... I'm sure I could keep going on with ways that this is a superior, unique method. This device has serious potential, and so do you.
You should cut the phone/app part out all the way. There is no need for it. If you want real time feedback you should make it a tone based system. Input the angle you want to sharpen at. Have the device sound a nice sounding tone when you are at your correct angle and if you are above or below have it sound a higher or lower tones respectively. If you want could have it log the data so you can see at a later time. Yo may need to spend a little bit more money on components, but there is zero money/time you would need to spend on development and testing of an app. Also you should try to avoid having your phone out in a kitchen as it can be a wet/greasy environment. Also you want to focus on your sharping and not a screen, you want to reduce the risk of cutting yourself. Everyone wants to add an app for the most trivial things, a lot of the time it is not needed. I didn't read any of the other comments yet, but the nature of what you do I'm sure there are other smart people that have already suggested something like this. You would be a real hero if you could come up with a quality jig that you can put in to production that is: A) Max sale price $ 35 USD B) Able to take different thickness/size sharpening stones (not high priced proprietary sharpening media) C) Adjustable angles D) Accommodate a wide range of knives (kitchen, pocket, large, small)
If the goal is to teach the angle, I think it would be cool if the pitch of the tone could suggest whether you're above or below the desired angle that you'd input to the interface. And then possibly the volume of the tone could tell you how far off you are. Does that make sense? I feel like that way, if it's about teaching the beginning knife sharpener how to eye-ball the angle, this would sort of get you closer to that goal. I like your idea too about looking down at the knife, versus the phone, because then your eyes get adjusted to what that angle looks like in your hands, and as you do it more and more, you get better at accurately gauging how much you're doing. Unrelated, but I read something similar in Rachel Ray's book years ago (I was bored, it was there, I had already finished my other book). She said that to gain speed in cooking, you need to move away from busting out the measuring spoons for spices, herbs, etc. She said every time you do measure out an ingredient with a spoon for cooking (not baking), to put it into your hand before dumping it in the recipe. Before long, you start understanding what a teaspoon of (for example) salt looks like in the palm of your hand, what pepper looks like, what herbs look like. Once you have that down pat, then you become better at free-styling when a recipe asks for multiple ingredients in multiple amounts. I really like your idea of a dedicated device!
Or a simple, cheap, small text Display on top, plus two buttons - to allow the angle to be set up. Not any device needs Bluetooth. It's kinda pointless.
Hi Alex. As for the movement technique I recall from some woodworking videos they advice to lock your upper body (keep elbows close to torso) and instead use just your hip and knee movement. This makes it much easier to maintain angle for sharpening chisel and handplane blades. Really enjoying your channel - keep it coming!
If you're trying to learn to sharpen the knife as close to your desired angle as possible, you can have the microcontroller or phone sound an ascending tone if the angle is too low and a descending tone if it's too high. That way you can focus your eyes on the blade.
A jig is also a lot more setup, also this device once mass produced could be both more precise and cheaper. Cheap jigs often get loose, that's partially why people pay the big bucks for the system that Alex mentioned which is quite good and a good option. I think as a pedagogical tool for freehand sharpening his idea could be fantastic, and frankly once you're good at freehand sharpening jigs are pointless.
why not use a wedge, with a sliding mechanism, holding it beside the sharpening stone (so as to not gunk it up with any material coming off the wedge)? always great to learn new skills, but this really seems like an overengineered solution that doesn't even really work properly. In my opinion, you created something that tells you you're doing it wrong (as in, youre not at the right angle), instead of building something that helps you maintain the right angle (which in my opinion would be more effective). edit: hadn't finished the video when writing my comment. I wish you good luck trying to learn what others probably have spent years to master :P
I rather like this idea. How about making making the sliding mechanism part of the base that is frequently used for holding water stones? There are already little wedge guides you can buy, but these would have to be large enough to grip and snap into something like an arm coming off the base, You could clip in a wedge for whatever angle you want, rest your knife against it and the wedge/arm would allow guided forward and backward movement on the stone. It would allow people to continue to use their water stones which are largely the choice of professionals. Only downside I can see is that knives with a lot of curve/belly would still be tricky.
You are AWESOME!!! I think what might work is a magnetic wedge that attaches to the blade so that you don't have to worry about the irregularities of hand movement. You could have wedges of various sizes for each knife's requirement.
Altay Bayraktar I didn't dislike it, but you can do the same thing with a simple bubble level, a hot glue gun, a piece of wood, and 5 minutes with a saw. Some people may see it as unnecessarily over complicated.
a bubble level wouldn't work very well when you are moving it around so much, which would defeat the whole point of it, being able to see what angle you're at while you're sharpening
Alex, you are making me regret not paying more attention in high-school! I graduated a French-language high-school but wasn't really into it at the time. To quote the video "mmmmerde"!
Oh now that's interesting. Just make a jig that holds the knife in place at an adjustable angle and a set of rails so you can move the stone back and forth. With the wrong design though you might have trouble keeping a consistent pressure on the blade. Definitely a good idea though!
The best solution to have it teach you is to add a piezo speaker that uses a tone, set the desired angle parameters and it does continuous tone as long as you stay within the parameters. This would easily cue you to stop when the noise stops. There is also numerous diy videos to make your own printed circuit boards, you can design your own board and be able to print them pretty simply, plus this would let you label component locations.
Salut Alex, can you build a machine that can move the stone instead of moving the blade? With your device, you can hold the best angle during the sharpening process.
Sébastien I thats a great idea and it would probably be easier but the whole idea behind his device is to learn how to hold a 15° angle while sharpening the traditional way
There’s also the challenge of creating a sliding holder for the whet stone that 1) maintains a constant - within 1/10th a degree - base as it slides back and forth; and 2) accommodates whet stone wear over time. Mine, for example, has worn to be somewhat concave in the middle. FWIW...
There's something already out there called a "mini digital protractor" that I've used to find the angle of a saw blade when cutting wood. You may need to take it apart to change the orientation of the screen and add a feature for feedback. I would recommend a light or a beeping feature as haptic feedback or shocks may cause you to lose your angle.
Watches one video.... On recommendations every day since
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Hey. I like this project, as I have also noticed that I'm not as consistent with my angles as I should be. I would: - Ditch the smartphone. Having the data is nice, but hard to grasp while sharpening - Instead, use the leds on the device itself (the round one Becky used). A central one which lights up when you are at the right angle, and one or more to each side to indicate when you're too steep or too shallow. - A rotary knob to select the desired angle. The leds from before indicate which angle you select (with labels on the pcb itself), with 4 or 5 commonly used angles to select from. - A button to enter "select angle" mode. The angle should be zeroed once you leave "select angle"-mode. With these, the workflow would be: Put the device onto the knife, place it flat onto the whetstone. Press the button to enter "select angle" mode. Select your angle. Push the button again to zero the angle and enter sharpening mode. Now turn the knife until the middle led lights up. Keep your eyes on the knife for the whole sharpening process (as you should do anyways).
Probably useless advice and input from me: artists don't usually draw at that angle you're trying to sharpen at because it introduces wacky instabilities in our lines. We primarily draw from our shoulders at an angle going from the bottom of our nondominant side to the upper area a bit past our dominant side. This allows us to draw straight lines and keep our elbows and wrists relatively locked. Keeping these joints locked may help you maintain a more consistent angle. I'd suggest at least trying a similar technique for your knife and see if it helps you reduce the changes in angle.
Kudos to you for not keeping this under wraps because i would ve wanted you to do it and its genius you are making the public test it since you both becky and alex own the trademarks for the device probably, so i guess its all an elaborate genius to sell the trademarks later on or build your own company whichever happens first
yeah. Simple. Why spend a section of the brain to train to do it when it can be reserved to something else. Let a mechanical device solve it, and have it do so with very little error too. the only problem I see is that some knives are a bit curved, hence why a mechanical device would really have to be complex to achieve what a human hand can
It's like driving a stick shift. Sure, it's not the most effective way to drive a car or sharpen a knife but it's fun because it's a challenging and tactile experience. For me,, having to concentrate on a task that is normally taken for granted can have a somewhat meditative effect
I love this. There are many ways to get a perfect edge, and many methods that can be used. What I love about this is that it's applying technology to provide for a way to refine skill. Speaking to the comments about watching the device or the screen during sharpening, I don't believe that was the intent. But rather that the data can be used to show the progress of the skill consistency being acquired. A function of data that I think goes underutilized in many cases. Sometimes all we need is concrete evidence that a skill is being improved to motivate us to continue to improve it.
You could add a speaker with a tone output that chirps differently when the blade goes above or below your desired setpoint on the ardunio. Thanks for the great shows Alex!
personally, I think Becky had the best idea with the green light telling you if your angle is right or not. it keeps everything in front of you where your working.
I think whenever there's a sudden change in acceleration of the knife - back to forward, forward to back - the box probably jerks slightly, changing the angle measured at that moment, even if the knife itself is at a more constant angle. The values shown seem to show this kind of oscillation with the back and forth motion.
You know there are people with tics and nerve damage who can not cook in the kitchen because their muscles will launch the knife. It's not funny, it's disabling.
Mike ingrum That wouldn’t be a good idea. Every time you get shocked, your hand(s) will twitch, changing the angle once again, most probably making you go even further off the right angle. Also, nobody should be shocked - however small the shock may be - with a knife in their hands.
I'd love to see an onboard display with live angle feedback. Maybe like a guitar tuner, or tuning pedal does. There's lots of clever ways to do this, as far as bleeps and bloops of lights or meters. Also, it'd be cool to see your average angle, and other mathematic type numbers that would tell you how good your spread is between all your pushes. Because even an erratic series of pushes can land a good average. First time commenter, long time viewer. Love your channel dude. I'd love to see this come to life.
Hey Alex, I'm not much of a cook, but I am a bit of a carpenter specialising in hand tools and handtool restoration (because they're usually cheap to buy rusty, and made of quality old-fashioned ingredients rather than modern high-carbon steel). I've spent hundred of hours sharpening everything from 1/8" chisels and gouges to draw knives and even drill bits. With your technique - I think I can help. You introduce deflection by moving the blade in any direction that is not parallel to the surface of your stone - this can be from your shoulder, elbows, wrists or fingers. When I sharpen, I take a wide stance (I'm 6'5" so I need to get low) so my hips are level with the surface of my stone, find my angle, then lock my arms and upper body in position and move only my legs and hips, sort of rocking your whole body. This will keep you much closer to your angle as any deviation with only vary pressure from your edge to the stone - do not compensate for this with your hands! This is the hardest step! You obviously have a good understanding on how F=MA affects cutting, but remember that the angle isn't really crucial - certainly a large angle means the tip of the blade is hard wearing, as it has loads of supporting metal to keep the tip in place - the blade is only sharp if the left bevel or edge intersects with the right bevel or edge. You want to have it even on both sides. If the intersection point waves left and right, which is really easy to do if you take off more material on one side, the knife may cut unpredictably. Having a camber (a convex curve) on the blade is not a bad thing, it can help guide material away from the plate of the blade and lessen the friction around the cutting edge. So again, angle isn't super important. I work with wood, and we have a lot more variety of things to cut, especially things like 'burl' where the grain runs in circles - for this, an extremely low angle blade is essential, you want to peel away layers as slowly as possible to not cause damage to the piece. With a chefs knife, you're generally cutting through vegetable matter or meats, so you really don't need a precise angle - you just need it to be consistent on both sides. If you deviate on one side, so long as you deviate the same amount on the other side - you'll be fine! Just look at the cuts you took on the tomato! Something I don't see you do (or I have totally forgotten seeing you do..!) is to strop the blade. Either using a steel or a leather strop and some polishing compound. This may not be super important for a kitchen knife, but I always like my blades to be a perfect mirror when I'm done - but as my blades are usually 2-5mm thick, my edge is much larger! Anyway - thanks for a great video. And if you do read this - thanks for the ramen series. I absolutely loved your pasta machine hack - looking forward to seeing more insane kitchen inventions!
when keeping an angle put your finger behind the back/underside og the blade, position the angle and lift slightly above the surface of the wetstone, if you touch the stone that indicates that your not keeping an angle, as you are pushing forward your more likely to mess up the angle on the forward strokes than backstrokes. making this technique absolutely fantastic
JEIL I don’t know what video you just watched, but he only took off his pullover, he still had his t-shirt on. And he probably did that because he was too hot.
Yea. I didnt mean he was naked but he took off his outer top for the skype and put it back on immediately after. I just thought maybe I should be doing this when I skype.
Continuity? The Skype call was made much earlier, when he had a different shirt on. He filmed some parts of this video with the sweater, and didn't want to redo them. So he does the changing thing before and after the pre-filmed call segment, so the differing attire isn't as shocking. That's my guess.
I would have chosen to make a mechanical support angle, clipped on a wheel/several wheels or tube? that would be height adjustable with a screw. Once you set the height the knife would not be able to change height. I am basically lazy and look for the easiest/less stressful solution -- you have sooo much patience!
No offense, but I believe you over engineered this one (perhaps just to much for others to replicate). The super simple and easy angle finder is called a domed bubble level. it is a tiny air bubble trapped inside a dome shape that is filled with colored liquid (you're an engineer, why am I explaining this to you? you already know what it is). It can be made yourself pretty easily and then calibrated and marked by hand simply using the geometric tool you made before. You wont be able to take into account the acceleration factor while in use (unless going very slowly over the stone) like you could with this arduino build, but for general feel for the lie of the knife it is simple and requires no knowledge of more complicated engineering things. You've always wanted to keep things simple for the audience, I think this may be a simpler DIY solution. My parts list include: some domed shaped object that can hold water, I was thinking like those plastic 2 piece kids toy containers from vending machines, a small magnet, food coloring, a marker, and your cardboard angle cutouts. I hope you can see where I'm going here. This is gritty and again wont correct for acceleration but will give you a good angle feel for way cheaper and with less engineering needed.
One word: sloshing. If the dome is shallow enough to be sufficiently sensitive and the fluid has a low enough viscosity to be "real time", the bubble is going to be all over the place. Don't get me wrong, a bubble level is great for getting the initial angle... but it won't track well enough to develop muscle memory during the sharpening process unless the knife remains still and the stone moves.
Several people have suggested audio input, but given how nearly impossible it is to be as precise as the sensor is, instead of a simple high/low beep, I'd have a steady tone that changed frequency and volume, higher pitch for higher angle, lower pitch for lower angle, and decrease the volume as you get closer to the target angle, so it's a pleasant low hum when you've got it right, with minor tone variation as you deviate. You could also have skill level settings that narrow down the range the tone varies over as you improve.
Ariel well the call was probably recorded a while ago and to keep consistency between shots he "changed in to" the shirt he was wearing when he recorded the video.
Ariel well the call was probably recorded a while ago and to keep consistency between shots he "changed in to" the shirt he was wearing when he recorded the video.
You could also use a reaction wheel to exert a force on the knife towards the correct angle, with a lighter force applied the closer you get to the correct angle. There are some issues with this approach (For example, if you are constantly on the same side of the angle (e.g. too shallow), the reaction wheel would eventually reach its max speed and stop working), but I think it would be a really cool approach. You would feel the knife wanting to go towards the correct angle, giving you instant feedback.
you could use an angle finder they are often used in woord working to find the angle of an table saw, there are even ones that stick to your blade with a magnet
You can do this with the iPhone as well. The level is built in to the compass app. You might want to check it out as it might be more directly applicable to your audience. Thanks Alex... love the videos! If you stick with the arduino approach, I would add a sound. Perhaps the cadence could tell you how close to the correct angle your are. The closer together the "beeps" the closer you are to the correct angle. The further apart the beeps, the further off you are from the correct angle. Just some thoughts. I'm a tinkerer myself.
There are sharpening stations used by knife makers that use a mechanical means to keep the right angle, even at the tip(which you don't have with the digital angle gauge) It's just a stick with a stone attached to it and a vice for the knife. The stick keeps the stone at the right angle, as the knife is kept stationary.
You need a tone that gives you the exact angle. Silence for your desired degrees, and a little lower for too shallow and higher for too steep. THAT will train you and of course allow you to keep the right angle right from the start.
For an idea (not sure if it was covered in the other knife videos), would a small block of wood cut to the right angle work? it would be cheap and easy. As an improvement, make two gliding rails left and right of the stone (with rails below stone surface), and a little sled for the wood block almost touching the stone. Maybe even allow it so glide left and ride for an organic feel. You always can press the knife against the block, wont grind away the wood and move the right slowly left to right
Just mentioned on Becky's video that what would be immense would be to integrate a 10 segment LED bar that would give you a real time visual reference as to how far out you were. So let's say the middle two bars light up when you are within an acceptable range of the desired angle, but more LEDs light up in each direction if you drift away from the desired angle, say more LEDs down as you drop to far and more LEDs up as you drift too high. This would give you a more valuable and possibly intuitive way of adjusting as you go along. I might have a go at this Alex/Becky, thanks!
when i sharpen my straight razor, i use multiple layers of elecrical tape on the spine, some of the tape grinds off as well, but it keeps the angle perfect... when youre done just rip the tape off and enjoy your new edge, might not work as well for the rounded section of the knife though, good luck alex!
I think I’ve seen others mention it already but I would do away with the phone altogether and replace it with LED feedsystem directly on the circuit board. You could even simplify it down to a green and red feedback, wherein when the user is within the acceptable degree range, they see green, and once they go above or below that range, they see red. Interesting idea and I’ll be keen to see where it goes!
Hey! I think you should aim for a device like the ones for tuning musical instruments, with a display that show if you should increase, decrease or maintain your angle. I believe it would be much easier and intuitive than just reading the real time angle data. Your prototype is awesome and your videos are very inspirational. Congrats!
Hey Alex, add on my requirements - 1. A HUUGE angle value display on the mobile screen, so the angle can be read easily while sharpening.. 2. On top of it, a small graph of the past performance - 30 seconds or so, for feedback. 3. The angle update should stop if the hands stop moving in the sharpening rhythm. 4. Counting the continuous sharpening strokes without a 5 second gap. Similar to tripmeter and odometer, with individually resettable counters. All of these could help gain more insights, before one declares himself a master, and chucks the bluetooth device. Great idea though, and I backed off from berating you for not opting for a simple jig to help sharpening. Adding a steady hand is a great, coveted skill! All the best! But keep the videos rolling a bit more regularly please!
Having a stationary wedge you can put at the end of the whetstone (set to the angle you want) would help out a lot with stability, that way you know the start of your movement is always at the right angle
To throw a more mechanical approach into the mix. You could add a laser pointer to the knife and this way, you could see changes in the angle much better. The point will move because of the knife movement as well, but the change in angle will have much more influence on the position of the light point. You could just mark the start and end point at a perfect angle, where the point has to be at the start and the end of the wet stone and then just try to move the laser point only between start and finish.
The instrument you want already exists. Look into angle gauges for table saws and drill presses. You can get them from woodworking and machinists’ supply companies.
the easiest to me seems to be an acoustic feedback. Glider pilots use it for determining if they in or de cline. Thus angle a function of octave, will give you a immediate feedback how to correct the angle if not perfect. Keep on, I like your channel and if my comment improves, well then....
There are many comments, so I don't know if the following has been suggested. Perhaps it's possible to add a LED green/red to the device. Green would be programmed to light when the correct angle range is achieved. Red would show when outside the correct angle. You would not need to take you eyes off the blade and stone, and could train yourself to maintain the correct angle. Ideally, you could select which angle, for different knife styles.
You should put a red and a green led on top of the device. When you're at the right angle the green led will turn on, and when you're at a wrong angle the red led will turn on. This way you will be able to tell if you're at the right or wrong angle. Just an idea. Great video by the way, keep it comming.
What about using sound as feedback to the user? By placing a piezo-buzzer on the board itself (low pitched beeps if angle is too low, high pitched if angle is too high and constant tone if angle is perfect), you could have unnoticeable latency and you wouldn't have to constantly look at a device to know whether you're doing a good job.
This is a follow on from the reply from Samwise about introducing an audible element to the app to make it more intuitive. If you added two tones to the device I think you would very quickly learn to make instinctive micro adjustments to the angle . One tone that stays fixed at say 440hz would be a sensible value. Then a second which goes up and down in pitch as the blade moves off axis. The pitch drops when the angle is getting lower and raises as it increases. That way you will be able to tell when it's at the perfect angle as you will only hear a single tone (both tones at 440hz).
you would need a simple sine sound depending on the angle ranging +/- 5 deg. This will help you find a stable position. The measurement app can do this with just a few lines of code.
Hey Alex, Try using small marbles fitted under the knife that would easily move along the stone keeping the same angle. Change the size of the marble for a different angle !! Works for me although I haven't measured the angle that each marble gives to the knife
Hey Alex, and idea on an improvement Put a speaker on the device which emits a frequency which changes based on if your angle is too low/high So the device can lock an angle of say 15 degrees and if you are sharpening at 10 it’ll play a high frequency sound indicating to increase your angle This way you can keep your eyes on the knife and still know any problems with your angle through sound.
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I love how you took off the sweater for the pre-recorded Skype call, and put it back on after. Continuity for the win!
I was like why the hell did he take his sweater off. This makes sense
Alex, you’re building a Bluetooth version of something woodworkers have had for years. Digital angle gauges. Wixy makes one for $20 USD, with a large lcd display, tare function, & it can be magnetically mounted to your blade. No need to reinvent the wheel if it will be more expensive and require phone connectivity.
I was about to write this same comment.
Thank you this was really uses full
Trouble with those digital angle gauges is their displays are oriented in the wrong plane for sharpening like that.
@@spencereagle1118 Looks like Wixley makes a version that also has Bluetooth on it! :) I might have to pick one of these up. Model: Wixey WR300BT
There's also a digital level on iPhones that would work and that gives a clear visual on the angle.Works in either orientation.
Awesome to work with you on this, Alex! 🔪🌟
Becky Stern +
Alex French guy and Becky, I have the answer to all your problems, and this will make your gadget totally marketable, and it's simplicity itself...A buzzer (and/or a light) that goes off if you're over 1 or 2 degrees plus or minus on your sharpening angle! A buzzer! All I want is a lousey 1% of every one you sell. Seems reasonable. ;)
Can you tell why he thought that he has to pull his sweatshirt off for skyping with you?
Alex, Becky, awesome work! I build DIY electronics for fun, and love watching cooking channels on TH-cam so it really feels like my worlds are colliding :)
put an led on the device that shows green while its in the range you want then turns yellow when its just outside the range and then red when your damaging the blade.
"I am really doing my best" - I can see that man, I can see that... Made my day!
Salut Alex, as said in the other video, I would really ditch the Bluetooth/phone part and replace it with LED on the board directly. When you sharpen you don't want to look anywhere else than at the knife as it could be hazardous. If you put 5 leds to the board you'd have the info right on the blade. It would also make the build cheaper and the battery last longer. And it avoids needing a phone, that also needs a charged battery, be compatible (less of a problem as you are using UART), blablabla. Love your vidéos :)
This. With a built in 'reset angle' button.
and an angle button so you can change the angle setting using the same LEDs to select the mode (15-17-20, etc) you get the idea.
As Gillermo said, we need a reset angle button to 0 it out on the stone before putting it on the blade, because if it gives you an absolute angle and the stone has 2° offset, you are off.
I would put some kind of LCD to show accuracy like an analogic display, like a guitar tuner.
Looking for example like this [ |### ]
This LCD should be on top of the device to be able to read it (on the side I mean).
BT can be used to change settings of the device with a nice app for blade selection for example.
You could get a similar effect with a piezo buzzer
You, sir, are a true Renaissance man. You are now one of my new favorites. I found you through one of my other favorites, This Old Tony. It gives me a warm fuzzy feeling to know that guys like you and TOT are out there doing your thing. Excellent work.
Alex French Guy Home Electronics
Spread it like voltage.
spread it like soldering flux
Spread it like thermal paste.
Spread it like fiberglass, butter it like circuits.
azdgariarada I was thinking perhaps have a a few settings on the device that when at optimal angle it lights up so you know your have the right angel. I was Army for 14 years so I have a few ideas when it comes to sharp knives.
At the right f***ing angle!
I've only recently discovered your channel, and it is quickly becoming one of my favourites! Your projects are great, editing is razor sharp, music is lovely and you are just fabulous! Keep up the good work, Alex :)
Consider adding variable haptic feedback proportional to the degree of error, perhaps with high and low sounds to indicate over and under angle variances.
Jayyy Zeee excuse me sir but how did you read my mind? We need to get this upvoted because this is probably the most promising Avenue
I was literally thinking the exact same thing! In my head there would be a little green LED when you were within the tolerance and have a red one light up when you’re not. And even maybe have an amber one to indicate you’re getting close to being in the red. Could this even be done with a single LED nowadays? Anyway it was film SLRs with an LED exposure indication in the viewfinder that I got the idea from.
To me having this haptic feedback would be a good way to train yourself in a tactile way. It would give you instant feedback and allow you to adjust accordingly.
Perhaps there could be different feedback for different types of learners? Visual, auditory, read/write (like Alex’s current method)?
Just some ideas I had.
Shock him everytime he gets 2% off ;p
Totally agree, this is the best way to go.
skyeandy, yes there are LEDs that have 4 pins instead of two, and can output pretty much any color.
Gotta love your approach on those damn useful project! Ça fait pas longtemps que je t'ai découvert et franchement j'adore ta façon d'aborder le story-telling 👌
A tone when you're at the proper angle would give you an idea of the "feel" to achieve the desired angle and train your muscles to maintain a consistent level.
You might try setting the stone itself up at a 17 degree angle and holding the knife perfectly horizontal as you sharpen. Your senses are more naturally attuned to detect and maintain perfect level than a specific degree of angle, so it's easier to hold the knife consistently flat than to hold it at a fixed angle. You can still use the sharpening device you made to check for consistency.
I always found that electric shocks (in this case to your hands) when you fall outside the angle range (ie ± 2 degrees) will give you faster bio-feedback than monitoring a small screen. Subbed after just 30 seconds. You are fun. Nice spirit.
I love seeing someone who is as passionate about knife and tool sharpening as I am. Thanks Alex.
Salut!
I've never seen the sponsor button before, Alex I think youtube is in love with you!
Thanks for teaching people one of the most important skills needed in the kitchen.
I'd never go this far, even as a sushi chef BUT
this really is an awesome concept, you're so insane Alex!!!
beaucoup de respect
wow you are so concentrated while sharpening! you are awesome!
for your little project i think i will take a different route, a smarter but more indipendent little device
a small lcd screen for i/o, one button for the initial zeroing, one for increasing the angle, one for decreasing, and one for starting/ending the sharpening session
keep working on this project!!!
Hey Alex, one thing to note about using a whetstone, especially Japanese waterstones, is that they tend to start turning concave as you use them. There's some debate in knife circles whether its enough to just use the nagura (cleaning) stone regularly, or whether you have to use a full flattening stone to completely flatten it at some point. Some would even go as far as to flatten their stone after or before every use. I'm more of the camp that using a nagura stone is enough and that the stone itself doesn't need to be perfectly flat to get good results. That means, however, that my sharpening angle, relative to perfectly flat, is going to change between sharpening sessions. Unfortunately, those cardboard angle guides are more likely to give you a more adaptive result becuase they tell you the angle relative to the current shape of your stone, whereas the arduino device always assumes a perfectly flat surface. I'd actually recommend just learning by feel. Muscle memory will eventually take care of the rest.
I'd say flatten it as many times as possible, but if it fails, you should find a way to make it go back to normal.
The reason they go concave is from incorrect angling/tippingduring the course of the stroke.
@Becky You are really cool for makin' this, Keep on being freakin' awesome! @Alex I've got so much respect for you trying out new things the way you do!
Love your videos Alex. You're like the Casey Neistat of cooking, only actually likable.
De gustibus... but you don't have to be rude about it.
Huh? Who am I being rude to?
That is so funny! (I'm not being sarcastic, Casey is super annoying at times)
onlycasual1 hur dur dur who me rude to??
Its the accent lul
I have to say your idea is briliant and you are man of action
Look up a Wixey digital angle gauge - they use them to measure (very accurately) table saw blade angles.
That's exactly what I was thinking! lol
You should make the output from the phone auditory! That way you won’t have to look but you can hear if you’re doing a sharp job.
For example: maybe the angle of attack can be related to a certain pitch. Higher angle, higher pitch and the other way around.
I love your projects and videos! Keep ‘em coming, I’m curious about the development of this tool :)
Wow, that's pretty high tech. For me, personally, I put a convex angle all on my knives (they aren't kitchen knives, though). With a convex edge, keeping a consistent angle doesn't matter quite as much. Great video! God bless!
Will K Same here Will even on kitchen knives. Holding a precise fine angle maybe makes them incrementally sharper but how sharp is sharp. I can shave frog fuzz with a convex angle and it makes the edge stronger too.
Tri Monster the bevel is slightly rounded instead of sharpening a perfect V shape.
To add a bit to Will's answer, Alex here is sharpening on a whetstone. The material will not deform in any way during the sharpening process, and so he is left with an edge that turns out flat. Well, in theory... more on that in a moment. When you want a convex edge, you sharpen on a medium that isn't as firm (e.g. a leather strop, or a mousepad with a piece of sandpaper on top.) The end result is that your edge is curved outward slightly, and tends to be a bit stronger due to the extra material backing it up. It's difficult to obtain the angles desired in most kitchen knives, though, and though Will suggests angles matter less, they are still plenty important, and are augmented by pressure now being a concern. Thing is, when freehand sharpening on a whetstone like Alex here, you can't maintain perfect angles (as is the point of this video) and so you actually end up with a sort of convex edge yourself; many flat angles of different degrees creating a slight curve.
Convex sharpening, especially on a wetstone, needs a lot of experience but indeed, it holds the sharpness much longer and is easyer to refresh with the steel rod. I used this technique even for my Damaskus knifes before I changed to Windmühlen Messer (Robert Herder). They use a historic thin blade technology, and it doesn't matter of 17, 25 or 30'
I was typing Lansky just as you said it lol.
But this method is truly genius. the user provides their own stone. this device could have a stroke counter; its very easy to space out and lose count on particularly dull blades as you spend a long time sharpening them. there are no parts, screws, rails or pins that would get lost... I'm sure I could keep going on with ways that this is a superior, unique method.
This device has serious potential, and so do you.
You should cut the phone/app part out all the way. There is no need for it. If you want real time feedback you should make it a tone based system. Input the angle you want to sharpen at. Have the device sound a nice sounding tone when you are at your correct angle and if you are above or below have it sound a higher or lower tones respectively. If you want could have it log the data so you can see at a later time. Yo may need to spend a little bit more money on components, but there is zero money/time you would need to spend on development and testing of an app. Also you should try to avoid having your phone out in a kitchen as it can be a wet/greasy environment. Also you want to focus on your sharping and not a screen, you want to reduce the risk of cutting yourself. Everyone wants to add an app for the most trivial things, a lot of the time it is not needed. I didn't read any of the other comments yet, but the nature of what you do I'm sure there are other smart people that have already suggested something like this.
You would be a real hero if you could come up with a quality jig that you can put in to production that is: A) Max sale price $ 35 USD B) Able to take different thickness/size sharpening stones (not high priced proprietary sharpening media) C) Adjustable angles D) Accommodate a wide range of knives (kitchen, pocket, large, small)
If the goal is to teach the angle, I think it would be cool if the pitch of the tone could suggest whether you're above or below the desired angle that you'd input to the interface. And then possibly the volume of the tone could tell you how far off you are. Does that make sense? I feel like that way, if it's about teaching the beginning knife sharpener how to eye-ball the angle, this would sort of get you closer to that goal.
I like your idea too about looking down at the knife, versus the phone, because then your eyes get adjusted to what that angle looks like in your hands, and as you do it more and more, you get better at accurately gauging how much you're doing.
Unrelated, but I read something similar in Rachel Ray's book years ago (I was bored, it was there, I had already finished my other book). She said that to gain speed in cooking, you need to move away from busting out the measuring spoons for spices, herbs, etc. She said every time you do measure out an ingredient with a spoon for cooking (not baking), to put it into your hand before dumping it in the recipe. Before long, you start understanding what a teaspoon of (for example) salt looks like in the palm of your hand, what pepper looks like, what herbs look like. Once you have that down pat, then you become better at free-styling when a recipe asks for multiple ingredients in multiple amounts.
I really like your idea of a dedicated device!
Or a simple, cheap, small text Display on top, plus two buttons - to allow the angle to be set up. Not any device needs Bluetooth. It's kinda pointless.
omg this seems great
Hi Alex. As for the movement technique I recall from some woodworking videos they advice to lock your upper body (keep elbows close to torso) and instead use just your hip and knee movement. This makes it much easier to maintain angle for sharpening chisel and handplane blades. Really enjoying your channel - keep it coming!
Can't find the original videos now, but check out how this guy is working th-cam.com/video/xyjR-8uNR8I/w-d-xo.htmlm21s
those anging things exist already there used in making sure that circular saws are at the right angle
If you're trying to learn to sharpen the knife as close to your desired angle as possible, you can have the microcontroller or phone sound an ascending tone if the angle is too low and a descending tone if it's too high. That way you can focus your eyes on the blade.
using a jig is alot easier and precise
and cheaper!
This was my initial reaction too, but I think maybe Alex just needs to focus on selling it as a training tool for learning freehand sharpening
Maybe watch the whole video before you comment
Christopher i did, i know he says he could use a jig. his item hes trying to make a sell is pointless, a jig costs less and is more precise
A jig is also a lot more setup, also this device once mass produced could be both more precise and cheaper. Cheap jigs often get loose, that's partially why people pay the big bucks for the system that Alex mentioned which is quite good and a good option. I think as a pedagogical tool for freehand sharpening his idea could be fantastic, and frankly once you're good at freehand sharpening jigs are pointless.
Alex and Becky in the same video! Never thought that would happen, but I'm so glad it did :)
why not use a wedge, with a sliding mechanism, holding it beside the sharpening stone (so as to not gunk it up with any material coming off the wedge)? always great to learn new skills, but this really seems like an overengineered solution that doesn't even really work properly. In my opinion, you created something that tells you you're doing it wrong (as in, youre not at the right angle), instead of building something that helps you maintain the right angle (which in my opinion would be more effective).
edit: hadn't finished the video when writing my comment. I wish you good luck trying to learn what others probably have spent years to master :P
I rather like this idea. How about making making the sliding mechanism part of the base that is frequently used for holding water stones? There are already little wedge guides you can buy, but these would have to be large enough to grip and snap into something like an arm coming off the base, You could clip in a wedge for whatever angle you want, rest your knife against it and the wedge/arm would allow guided forward and backward movement on the stone. It would allow people to continue to use their water stones which are largely the choice of professionals. Only downside I can see is that knives with a lot of curve/belly would still be tricky.
This is a thing already (Wicked edge,lanksy,ect). Sharpening a belly is absolutely no problem with one of those devices.
Thank French Guy, it’s definitely stuff to think about.
"More like Ta-Dah thank god its over." You always amuse me Alex xD.
That was great! Sharpening is always difficult. I also really appreciate your sink/sandstone set up
"Food is not limited to a plate." ™
Jeff ! 🙏
You are AWESOME!!! I think what might work is a magnetic wedge that attaches to the blade so that you don't have to worry about the irregularities of hand movement. You could have wedges of various sizes for each knife's requirement.
How can someone dislike this?
Altay Bayraktar I didn't dislike it, but you can do the same thing with a simple bubble level, a hot glue gun, a piece of wood, and 5 minutes with a saw.
Some people may see it as unnecessarily over complicated.
Believe it or not the world is full of jerks:)!
They could have stopped watching and jumped into traffic:)!
But no they watched and disliked:(
a bubble level wouldn't work very well when you are moving it around so much, which would defeat the whole point of it, being able to see what angle you're at while you're sharpening
Alex, you are making me regret not paying more attention in high-school! I graduated a French-language high-school but wasn't really into it at the time. To quote the video "mmmmerde"!
dont move the knife, move the stone. it will help you to keep the angle
Oh now that's interesting. Just make a jig that holds the knife in place at an adjustable angle and a set of rails so you can move the stone back and forth. With the wrong design though you might have trouble keeping a consistent pressure on the blade. Definitely a good idea though!
it's the basic idea behind a sharpening wheel
That's essentially what a lot of the other systems out there do, including the one he mentioned/pictured. Usually not cheap though.
The best solution to have it teach you is to add a piezo speaker that uses a tone, set the desired angle parameters and it does continuous tone as long as you stay within the parameters. This would easily cue you to stop when the noise stops. There is also numerous diy videos to make your own printed circuit boards, you can design your own board and be able to print them pretty simply, plus this would let you label component locations.
Salut Alex,
can you build a machine that can move the stone instead of moving the blade? With your device, you can hold the best angle during the sharpening process.
Sébastien I thats a great idea and it would probably be easier but the whole idea behind his device is to learn how to hold a 15° angle while sharpening the traditional way
There’s one problem with that
If your not controlling the speed you might remove too much metal on accident
Grnnr you could have a pedal for the movement like a sewingmachine
There’s also the challenge of creating a sliding holder for the whet stone that 1) maintains a constant - within 1/10th a degree - base as it slides back and forth; and 2) accommodates whet stone wear over time. Mine, for example, has worn to be somewhat concave in the middle.
FWIW...
There's something already out there called a "mini digital protractor" that I've used to find the angle of a saw blade when cutting wood. You may need to take it apart to change the orientation of the screen and add a feature for feedback. I would recommend a light or a beeping feature as haptic feedback or shocks may cause you to lose your angle.
Watches one video....
On recommendations every day since
Hey. I like this project, as I have also noticed that I'm not as consistent with my angles as I should be.
I would:
- Ditch the smartphone. Having the data is nice, but hard to grasp while sharpening
- Instead, use the leds on the device itself (the round one Becky used). A central one which lights up when you are at the right angle, and one or more to each side to indicate when you're too steep or too shallow.
- A rotary knob to select the desired angle. The leds from before indicate which angle you select (with labels on the pcb itself), with 4 or 5 commonly used angles to select from.
- A button to enter "select angle" mode. The angle should be zeroed once you leave "select angle"-mode.
With these, the workflow would be: Put the device onto the knife, place it flat onto the whetstone. Press the button to enter "select angle" mode. Select your angle. Push the button again to zero the angle and enter sharpening mode. Now turn the knife until the middle led lights up. Keep your eyes on the knife for the whole sharpening process (as you should do anyways).
Probably useless advice and input from me: artists don't usually draw at that angle you're trying to sharpen at because it introduces wacky instabilities in our lines. We primarily draw from our shoulders at an angle going from the bottom of our nondominant side to the upper area a bit past our dominant side. This allows us to draw straight lines and keep our elbows and wrists relatively locked. Keeping these joints locked may help you maintain a more consistent angle. I'd suggest at least trying a similar technique for your knife and see if it helps you reduce the changes in angle.
awesome project, defenitely keeping an eye on it, since I am a sharpening geek too.
when you watched yourself back and told yourself to shush 🤣
Kudos to you for not keeping this under wraps because i would ve wanted you to do it and its genius you are making the public test it since you both becky and alex own the trademarks for the device probably, so i guess its all an elaborate genius to sell the trademarks later on or build your own company whichever happens first
Entertaining, but I would totally take a fixed mechanical device over this for sharpening.
yeah. Simple. Why spend a section of the brain to train to do it when it can be reserved to something else. Let a mechanical device solve it, and have it do so with very little error too.
the only problem I see is that some knives are a bit curved, hence why a mechanical device would really have to be complex to achieve what a human hand can
It's like driving a stick shift. Sure, it's not the most effective way to drive a car or sharpen a knife but it's fun because it's a challenging and tactile experience. For me,, having to concentrate on a task that is normally taken for granted can have a somewhat meditative effect
I love this. There are many ways to get a perfect edge, and many methods that can be used. What I love about this is that it's applying technology to provide for a way to refine skill. Speaking to the comments about watching the device or the screen during sharpening, I don't believe that was the intent. But rather that the data can be used to show the progress of the skill consistency being acquired. A function of data that I think goes underutilized in many cases. Sometimes all we need is concrete evidence that a skill is being improved to motivate us to continue to improve it.
i always tend to forget that alex is an electrical engineer
Chris Hsueh Really? Or is this sarcasm?
im just being facetious
He actually was
And definitely not a mechanical engineer...
electronics isnt the same as electrical btw. One is about power and another is about signals
You could add a speaker with a tone output that chirps differently when the blade goes above or below your desired setpoint on the ardunio. Thanks for the great shows Alex!
Alex French Guy Not Cooking.
personally, I think Becky had the best idea with the green light telling you if your angle is right or not. it keeps everything in front of you where your working.
Yes.
I think whenever there's a sudden change in acceleration of the knife - back to forward, forward to back - the box probably jerks slightly, changing the angle measured at that moment, even if the knife itself is at a more constant angle. The values shown seem to show this kind of oscillation with the back and forth motion.
You need another part that attaches to your wrist and shocks you whenever the angle is off. The more off tge more painful.
You know there are people with tics and nerve damage who can not cook in the kitchen because their muscles will launch the knife. It's not funny, it's disabling.
Mike ingrum That wouldn’t be a good idea. Every time you get shocked, your hand(s) will twitch, changing the angle once again, most probably making you go even further off the right angle. Also, nobody should be shocked - however small the shock may be - with a knife in their hands.
I'd love to see an onboard display with live angle feedback. Maybe like a guitar tuner, or tuning pedal does. There's lots of clever ways to do this, as far as bleeps and bloops of lights or meters.
Also, it'd be cool to see your average angle, and other mathematic type numbers that would tell you how good your spread is between all your pushes. Because even an erratic series of pushes can land a good average.
First time commenter, long time viewer. Love your channel dude. I'd love to see this come to life.
A wifi enabled knife
You can't cut with it until you download the app and srt up an account.
Hey Alex, I'm not much of a cook, but I am a bit of a carpenter specialising in hand tools and handtool restoration (because they're usually cheap to buy rusty, and made of quality old-fashioned ingredients rather than modern high-carbon steel).
I've spent hundred of hours sharpening everything from 1/8" chisels and gouges to draw knives and even drill bits.
With your technique - I think I can help.
You introduce deflection by moving the blade in any direction that is not parallel to the surface of your stone - this can be from your shoulder, elbows, wrists or fingers. When I sharpen, I take a wide stance (I'm 6'5" so I need to get low) so my hips are level with the surface of my stone, find my angle, then lock my arms and upper body in position and move only my legs and hips, sort of rocking your whole body. This will keep you much closer to your angle as any deviation with only vary pressure from your edge to the stone - do not compensate for this with your hands! This is the hardest step!
You obviously have a good understanding on how F=MA affects cutting, but remember that the angle isn't really crucial - certainly a large angle means the tip of the blade is hard wearing, as it has loads of supporting metal to keep the tip in place - the blade is only sharp if the left bevel or edge intersects with the right bevel or edge. You want to have it even on both sides. If the intersection point waves left and right, which is really easy to do if you take off more material on one side, the knife may cut unpredictably.
Having a camber (a convex curve) on the blade is not a bad thing, it can help guide material away from the plate of the blade and lessen the friction around the cutting edge. So again, angle isn't super important.
I work with wood, and we have a lot more variety of things to cut, especially things like 'burl' where the grain runs in circles - for this, an extremely low angle blade is essential, you want to peel away layers as slowly as possible to not cause damage to the piece. With a chefs knife, you're generally cutting through vegetable matter or meats, so you really don't need a precise angle - you just need it to be consistent on both sides. If you deviate on one side, so long as you deviate the same amount on the other side - you'll be fine! Just look at the cuts you took on the tomato!
Something I don't see you do (or I have totally forgotten seeing you do..!) is to strop the blade. Either using a steel or a leather strop and some polishing compound. This may not be super important for a kitchen knife, but I always like my blades to be a perfect mirror when I'm done - but as my blades are usually 2-5mm thick, my edge is much larger!
Anyway - thanks for a great video. And if you do read this - thanks for the ramen series. I absolutely loved your pasta machine hack - looking forward to seeing more insane kitchen inventions!
If the device has a small light with three colors
One for perfect angel
One for slightly ok angel
One for the wrong angel
Then it will be perfect
Better to have UP - OK - DOWN :) But instead of leds, I would put some kind of LCD to show accuracy like an analogic display. Like a guitar tuner !
Aren't all angels perfect, though?
Take a look at guitar tuners. I really like the haptic/auditory feedback idea to help train muscle memory.
when keeping an angle put your finger behind the back/underside og the blade, position the angle and lift slightly above the surface of the wetstone, if you touch the stone that indicates that your not keeping an angle, as you are pushing forward your more likely to mess up the angle on the forward strokes than backstrokes. making this technique absolutely fantastic
why did you take your shirt off to skype?
JEIL I don’t know what video you just watched, but he only took off his pullover, he still had his t-shirt on. And he probably did that because he was too hot.
Yea. I didnt mean he was naked but he took off his outer top for the skype and put it back on immediately after. I just thought maybe I should be doing this when I skype.
Continuity?
The Skype call was made much earlier, when he had a different shirt on. He filmed some parts of this video with the sweater, and didn't want to redo them. So he does the changing thing before and after the pre-filmed call segment, so the differing attire isn't as shocking.
That's my guess.
Probably for the same reason he takes off his shirt when he uses the toilet: habit.
@Mark Burtenshaw Yep. His hair was slightly different in the Skype scene.
I would have chosen to make a mechanical support angle, clipped on a wheel/several wheels or tube? that would be height adjustable with a screw. Once you set the height the knife would not be able to change height. I am basically lazy and look for the easiest/less stressful solution -- you have sooo much patience!
No offense, but I believe you over engineered this one (perhaps just to much for others to replicate). The super simple and easy angle finder is called a domed bubble level. it is a tiny air bubble trapped inside a dome shape that is filled with colored liquid (you're an engineer, why am I explaining this to you? you already know what it is). It can be made yourself pretty easily and then calibrated and marked by hand simply using the geometric tool you made before.
You wont be able to take into account the acceleration factor while in use (unless going very slowly over the stone) like you could with this arduino build, but for general feel for the lie of the knife it is simple and requires no knowledge of more complicated engineering things. You've always wanted to keep things simple for the audience, I think this may be a simpler DIY solution.
My parts list include: some domed shaped object that can hold water, I was thinking like those plastic 2 piece kids toy containers from vending machines, a small magnet, food coloring, a marker, and your cardboard angle cutouts. I hope you can see where I'm going here. This is gritty and again wont correct for acceleration but will give you a good angle feel for way cheaper and with less engineering needed.
One word: sloshing. If the dome is shallow enough to be sufficiently sensitive and the fluid has a low enough viscosity to be "real time", the bubble is going to be all over the place. Don't get me wrong, a bubble level is great for getting the initial angle... but it won't track well enough to develop muscle memory during the sharpening process unless the knife remains still and the stone moves.
Several people have suggested audio input, but given how nearly impossible it is to be as precise as the sensor is, instead of a simple high/low beep, I'd have a steady tone that changed frequency and volume, higher pitch for higher angle, lower pitch for lower angle, and decrease the volume as you get closer to the target angle, so it's a pleasant low hum when you've got it right, with minor tone variation as you deviate. You could also have skill level settings that narrow down the range the tone varies over as you improve.
Digital inclinometers already exist and there are several made specially for knife sharpening. Great video otherwise!
Sure, but I couldn't find anything particularly compact, which I imagine Alex is aiming for.
Great video. Get something that moves the whetstone while you (or maybe a clamp) grab the knife at the desired angle
Lol why the need to take off the sweater before the Skype call?
Ariel well the call was probably recorded a while ago and to keep consistency between shots he "changed in to" the shirt he was wearing when he recorded the video.
Ariel well the call was probably recorded a while ago and to keep consistency between shots he "changed in to" the shirt he was wearing when he recorded the video.
You could also use a reaction wheel to exert a force on the knife towards the correct angle, with a lighter force applied the closer you get to the correct angle.
There are some issues with this approach (For example, if you are constantly on the same side of the angle (e.g. too shallow), the reaction wheel would eventually reach its max speed and stop working), but I think it would be a really cool approach. You would feel the knife wanting to go towards the correct angle, giving you instant feedback.
Sharp Video
you could use an angle finder they are often used in woord working to find the angle of an table saw, there are even ones that stick to your blade with a magnet
You can do this with the iPhone as well. The level is built in to the compass app. You might want to check it out as it might be more directly applicable to your audience. Thanks Alex... love the videos! If you stick with the arduino approach, I would add a sound. Perhaps the cadence could tell you how close to the correct angle your are. The closer together the "beeps" the closer you are to the correct angle. The further apart the beeps, the further off you are from the correct angle. Just some thoughts. I'm a tinkerer myself.
I’ve had this same issue and questions for the last year or two. Love this
There are sharpening stations used by knife makers that use a mechanical means to keep the right angle, even at the tip(which you don't have with the digital angle gauge)
It's just a stick with a stone attached to it and a vice for the knife. The stick keeps the stone at the right angle, as the knife is kept stationary.
You need a tone that gives you the exact angle. Silence for your desired degrees, and a little lower for too shallow and higher for too steep. THAT will train you and of course allow you to keep the right angle right from the start.
Just awesome, the crazier you get the more awesome, only the French.
I love all your videos always a surprise
Thanks
For an idea (not sure if it was covered in the other knife videos), would a small block of wood cut to the right angle work? it would be cheap and easy. As an improvement, make two gliding rails left and right of the stone (with rails below stone surface), and a little sled for the wood block almost touching the stone. Maybe even allow it so glide left and ride for an organic feel. You always can press the knife against the block, wont grind away the wood and move the right slowly left to right
Just mentioned on Becky's video that what would be immense would be to integrate a 10 segment LED bar that would give you a real time visual reference as to how far out you were. So let's say the middle two bars light up when you are within an acceptable range of the desired angle, but more LEDs light up in each direction if you drift away from the desired angle, say more LEDs down as you drop to far and more LEDs up as you drift too high. This would give you a more valuable and possibly intuitive way of adjusting as you go along. I might have a go at this Alex/Becky, thanks!
The tuner-like light system that she had is pretty brilliant. I want dat.
You made this, and now I want it. To Kickstarter you go sir!!
when i sharpen my straight razor, i use multiple layers of elecrical tape on the spine, some of the tape grinds off as well, but it keeps the angle perfect... when youre done just rip the tape off and enjoy your new edge, might not work as well for the rounded section of the knife though, good luck alex!
Alex and adafruit... Never thought about it... Nice initiative man. Loved it.
I think I’ve seen others mention it already but I would do away with the phone altogether and replace it with LED feedsystem directly on the circuit board. You could even simplify it down to a green and red feedback, wherein when the user is within the acceptable degree range, they see green, and once they go above or below that range, they see red. Interesting idea and I’ll be keen to see where it goes!
Hey! I think you should aim for a device like the ones for tuning musical instruments, with a display that show if you should increase, decrease or maintain your angle. I believe it would be much easier and intuitive than just reading the real time angle data. Your prototype is awesome and your videos are very inspirational. Congrats!
Hey Alex, add on my requirements -
1. A HUUGE angle value display on the mobile screen, so the angle can be read easily while sharpening..
2. On top of it, a small graph of the past performance - 30 seconds or so, for feedback.
3. The angle update should stop if the hands stop moving in the sharpening rhythm.
4. Counting the continuous sharpening strokes without a 5 second gap. Similar to tripmeter and odometer, with individually resettable counters.
All of these could help gain more insights, before one declares himself a master, and chucks the bluetooth device.
Great idea though, and I backed off from berating you for not opting for a simple jig to help sharpening. Adding a steady hand is a great, coveted skill! All the best! But keep the videos rolling a bit more regularly please!
Having a stationary wedge you can put at the end of the whetstone (set to the angle you want) would help out a lot with stability, that way you know the start of your movement is always at the right angle
To throw a more mechanical approach into the mix. You could add a laser pointer to the knife and this way, you could see changes in the angle much better. The point will move because of the knife movement as well, but the change in angle will have much more influence on the position of the light point. You could just mark the start and end point at a perfect angle, where the point has to be at the start and the end of the wet stone and then just try to move the laser point only between start and finish.
The instrument you want already exists. Look into angle gauges for table saws and drill presses. You can get them from woodworking and machinists’ supply companies.
the easiest to me seems to be an acoustic feedback. Glider pilots use it for determining if they in or de cline. Thus angle a function of octave, will give you a immediate feedback how to correct the angle if not perfect. Keep on, I like your channel and if my comment improves, well then....
There are many comments, so I don't know if the following has been suggested. Perhaps it's possible to add a LED green/red to the device. Green would be programmed to light when the correct angle range is achieved. Red would show when outside the correct angle. You would not need to take you eyes off the blade and stone, and could train yourself to maintain the correct angle. Ideally, you could select which angle, for different knife styles.
I for one, can appreciate Becky's wall behind her. Love the brick!
You should put a red and a green led on top of the device. When you're at the right angle the green led will turn on, and when you're at a wrong angle the red led will turn on. This way you will be able to tell if you're at the right or wrong angle. Just an idea.
Great video by the way, keep it comming.
What about using sound as feedback to the user? By placing a piezo-buzzer on the board itself (low pitched beeps if angle is too low, high pitched if angle is too high and constant tone if angle is perfect), you could have unnoticeable latency and you wouldn't have to constantly look at a device to know whether you're doing a good job.
This is a follow on from the reply from Samwise about introducing an audible element to the app to make it more intuitive.
If you added two tones to the device I think you would very quickly learn to make instinctive micro adjustments to the angle . One tone that stays fixed at say 440hz would be a sensible value. Then a second which goes up and down in pitch as the blade moves off axis. The pitch drops when the angle is getting lower and raises as it increases. That way you will be able to tell when it's at the perfect angle as you will only hear a single tone (both tones at 440hz).
you would need a simple sine sound depending on the angle ranging +/- 5 deg. This will help you find a stable position. The measurement app can do this with just a few lines of code.
Hey Alex,
Try using small marbles fitted under the knife that would easily move along the stone keeping the same angle. Change the size of the marble for a different angle !! Works for me although I haven't measured the angle that each marble gives to the knife
Hey Alex, and idea on an improvement
Put a speaker on the device which emits a frequency which changes based on if your angle is too low/high
So the device can lock an angle of say 15 degrees and if you are sharpening at 10 it’ll play a high frequency sound indicating to increase your angle
This way you can keep your eyes on the knife and still know any problems with your angle through sound.