As a frenchman, the biggest flaw in this experiment is that the mat is not fixed. In a guillotine the head would be enclosed in a wooden frame. When using the 45 degrees angle the mat is rotating loosing a lot of energy. If the mat was fixed it would have been cut much easily.
The biggest clue of why 45 degrees blade should work better is at 7:11 as the blade cutting the wood is moving sideways and not fixed. With a fixed blade it would require much more energy to cut through wood. With changing referential 45degrees blade is equivalent to the blade moving sideways therefore « slicing » instead of pushing through.
i was about to say the same thing, in the actual guillotine execution the neck is being held down by a wooden clamp to keep the body from moving, on their demo not only does the mat moves around the moment its cut the mat roll were also "loose". if its tied down for a more firm mat roll like the one they use in katana slicing, the cutting would me more efficient and consistent.
As a french person (never thought I would say that in such a context), it feels to me that having some sort of piece of wood with a hole in it to prevent the mat from moving sideways would eventually help the cut with angled blades. Also, you can make the carriage a bit "higher", ideally higher than it is large, measuring from most distant wheels contact points in each direction, this way it would be much less prone to rotation.
The biggest clue of why 45 degrees blade should work better is at 7:11 as the blade cutting the good is moving sideways and not fixed. With a fixed blade it would require much more energy to cut through wood. With changing referential 45degrees blade is equivalent to the blade moving sideways therefore « slicing » instead of pushing theough.
also, you could just have a bone through the mat for most accuracy. Though the spine is made of vertebre so maybe they intentionally hit the space between them.
You being French was completely irrelevant to what you said. It's odd that there are 2 French people here who both felt the need to say they're French even though it had absolutely no relation to what they posted. If I was French, I'd keep that fact to myself.
@@KamikazeCommie501 Saying I am French was a joke (even tho I'm French for real) regarding the history of France with the Guillotine --' I'm sorry if I offended you, that was not my intent...
As a Canadian I completely agree, but would generally substitute "higher" for "taller". There's also something strange about the direction it torques as it hits, they say it's because one side is heavier, but I think it's because one side hits first and slows down as the centre of mass tries to keep moving. The biggest thing is to spread the torque load over a longer range, but they may only need to do so on one side, perhaps by adding a well-braced wheel a few feet higher than the rest, on the side that hits last.
I researched a bit and found that "An angled blade ensures that the force is applied progressively from one side of the neck to the other, rather than all at once. This reduces the likelihood of the blade getting stuck or requiring multiple attempts, ensuring a more humane (relative to the method) execution." So the angled blade doesn't necessarily means its better at chopping, it could just make it more consistent/less likely to get stuck.
Yeah surface area is why it works much better. Causes more of a slice compared to a chop. Some say this is why the curve in some curved swords helps, but testing has shown conflicting data. Or that the curve would need to be ridiculous in order to matter. Personally I think curved swords are better slicers due to other factors like being single bladed which allows a thick spine to commit it's mass behind the edge. The curve helps with the mechanics of the swing at many angles, and edge alignment. But yet my favorite blades are still forward curved blades like a Kukri, some Yataghans, and Falxs! Gimme the choppah! My question is this considered a draw cut on a few of these? I also want to see a one sided uh 10 degree blade in action. About as verticle as you can go, while having the tip be made to miss.
thanks! I find that sentence not to contain very much information. Because... why? How exactly? Why is progressive cutting better than all at once? But thanks nonetheless!
@@KnowArt Imagine the flat blade cutting a cylinder with a 1m radius. If the blade moves 1m downwards after touching the cylinder, it will have already cut half of the cylinder. A 45º blade doing the same motion would only have sunk 1/sqrt(2) = 0,71m into the cylinder and thus require less effort. The total work needed to cut the cylinder should be about the same, but the angled blade puts the same amount of work on a longer period of time so it requires less force and cuts more smoothly. This should also be why the blades performed about the same in the guillotine, with a fixed amount of energy behind each blade. The difference should be exacerbated by instead measuring the amount of force required to start cutting into the material; the angled blade requires less force to start cutting, but the blade has to travel longer to complete the cut.
@@KnowArt If it helps, in the video you said that the blade does not see much use, however, during the French revolution it saw an unbelievable amount of use every day, so much so that by the end of the day it could take multiple attempts to cut a head clean off.
They're designed for cutting meat! There's a HUGE difference, it's way more stretchy and shock absorbant than wood or fruits. The flat blade would just bounce off someone's neck and potentially break it in the process. I'm surprised noone pointed out yet, you should try cutting actually meat or balistic jelly in the next video.
It is the material in the neck which is tough, ballistic jelly is more of the softer muscles and tissues. Most meat will not be this tougher neck cartilage/ligament/bone/muscle mix. Modern metal is also far less likely to break under such stresses, so it is doubtful they could test that out very well.
I watch many videos where historical and modern weapons are tested for effectiveness. I highly suggest you do at least one (they are $$$, unless you can get them to sponsor/ donate one) BallisticDummyLabs i believe is one of the companies that produce full sized, torso, skull, and other simulated anatomy. (Zombie ones are best because the blood is green and won't get you demonotized or at least make it less likely) This would be THE ULTIMATE way to see the effectiveness, as they use different materials to simulate organs and bones, Then you can use a reproduction of the head holder and it would be as close to historical accuracy as you can, Also maybe get the throw away scraps from a butcher and that way you can find a piece of meat as thick as the neck, with as close as you can find musculature, fat, bone, to a neck. Everyone who is saying cut meat (which shows they don't watch to the end), doesnt mention that the other parts like the ligaments/ muscle/ other structures. Check out Ballistic Highspeed, Garand Thumb, and many more channels to see Balllistic Dummies (I reccomend the Tank vs dummy, RPG vs dummy, shotgun, and rifle. The tank basically turns you to mist and chunks, the RPG Quarters and beheads you, the shotties will make at least half of a head dissapear and the slowmo of the wound channels is scary to see how our bodies would temporarily have large cavaties due to the speed of the penetration. Awesome video, I enjoy this kind of History meats science and engineering, and we see stuff get destroyed! Excited for round 2 a gel dummy torso with head would be so amazing
A couple questions for the OP. When the equipment was in regular use. One, Did they have the technology to know the difference and did they really care which one would be better? Back then, a blade was a blade. I'm sure they had some advances at the time. Did they have the ones YOU'RE talking about?
The tatami you are using are indeed used for katana testing, but please be mindful that they need to be wet (not soaking, but moist) to properly be used.
as long as they are consistent between tests it's all good for us, I believe. I didn't want them to dry out throughout the day, so I kept them dry to begin with
@@KnowArt ah. that makes sense, but I belive the standard method is to just keep them in a bucket or something when you're cutting others- they don't work as well if you don't soak them you also want to roll them farily tightly- I think?
They are meant to be soaked overnight and then be left to dry to not be soaking wet afterwards. Even with your consideration the result may vary drastically. Imagine trying to chop a piece of firewood with a 10% moisture total or one with 60%. That is quite the difference.
This is what I suspect as well. Anything that minimizes the blade rotation should limit travel friction, and even a small increase in friction can make exponential differences in the results as it deflects energy sideways over the full length of the cut. This would go a long way toward explaining the similar results between the traditional and flat blades, as the flat one is better balanced.
@@faceoctopus4571 No they mean because it's a long strip mounted at an angle, it's the same width all the way across. The angled blades in the video have more material on one side than the other.
I am not sure that the weight distribution matters, if anything, it should be an advantage. During the fall, it is essentially a free fall, especially with modern bearings, so no significant torque would be applied. However, once it hits, the thick, heavy, part will hit first, limiting initial rotation because the center of gravity will be closer to where the force is applied, limiting torque.
As I remember they had to throw buckets of water on the blade at one point to keep it from warping. But as I understand it, at the height of the Revolution, sharpness was not a consideration. Maybe in the original design, but not as a matter of practicality.
Another possibility you could test is an inverted version of the point where they move inwards towards a point kind of like an "^" shape instead of a "v" shape
a lot of people with a lot of suggestions, but honestly your methodology was fine your equipment was just malfunctioning. The bearing assemblies are good, they just need to be longer. They can't resist the turning torque because they are too close to the source and don't have enough leverage. Making the carriage longer, and putting additional rollers on the end, would provide higher resistance but would give far better mechanical advantage to resist the cutting induced torque. An example would be something like a shaper, which has a very long rail compared to its cut/stroke depth, often less than half. This is because all the extra interface between the carriage and the rails allow for far higher rigidity, far better predictability, and less deflection at the cutting edge. OH and try to constrain the mats, and dont forget to soak them in water. IIRC the tatami mats are supposed to be soaking wet for cutting, although that may be lies fed to me by internet strangers.
I also thought that the wheels might be too close together, spreading them out might be a good idea. Looking up some guillotine images, the rail system seemed to have longer spread as well, for most of them at least.
@@LouisEmery tbh I just look like him and thought it was funny, although a lot of people have a lot of either very awful things to say or very interesting things to say. Your comment was definitely of the interesting variety lol
Some things to consider: - angling blade gives it more surface area, is there a reason that's needed? - the angle might be for other factors than cutting efficiency or sharpness - necks are squishier with a bone core (does angle improve getting through that specific material? Would the neck 'jiggle' too much if the blade was flat? Was it for a much cleaner cut for 'presentation' after?) - necks are messier (does the angle control mess?) - shape could be legacy from other methods (ax shape?) - shape could be legacy from a tool (" we need this thing, take that peasant tool that cuts really well and make it bigger!" - maybe like a scythe) - it could be that historical guillotine blades worked so well for their given task that no one really took the time to make it more efficient
thanks! great list. Didn't consider that there might be a reason other than pure cutting efficacy. The best source we have about the origin of the angled shape is the great grandson of the maker of the first guillotine. In his story he tells that the king of france (who was fat) told the maker that the flat blade that was on the first drawing wouldn't work for big necks. The maker looked at the king's neck and agreed. The king then suggested an angled blade, and was ironically beheaded a couple years later, in the french revolution. But the story doesn't tell anything about the true reason why it would be better, but it implies that it's not a leftover from axe designs or anything like that.
@@KnowArt it likely comes down to the physics of slicing rather than pure efficiency (what you're testing for). Any angle will increase cutting force required (45 degrees just being (blade width / sin(45)), so 41% more force required). But when it comes to hard materials that you want to slice rather than crack, as with your car/mountain example, the cutting efficiency is higher at an angle because the relative blade angle is finer, allowing for the cut to go deeper into the substance before the spine (of the blade) is engaged and cracking / wedging is the only force involved in the splitting. It's odd to say that something takes more force but is more efficient, but that simple math doesn't take into account the mush easier time an angled blade has at initiating the cut (usual range is 25-50% better), but I can't do that math without the specifics of both the material and blade geometry. One of the main issues with your set up is the use of the mats, they're woven, and loose. A flat blade should behave the best in this scenario as it can compress the mat into a stationary mass, plus interlocked fibers tend to resist slicing. It's the same reason that a flat blade will have an easier time going through woven kevlar than a slicing blade.
@@user-cg7nd9er4l Do you know of better ways of spending your time than improving of an already great design? The other day I was reading about wealth inequality. My brain took me automatically to the wiki page about the machine monsieur Guillotine popularized. Now YT is offering videos of these guys. I consider my journey a time well spent!
@KnowArt It’s a "leftover" from a lot of different weapon designs. The angled blade allows for a nice continuous slice, focusing the energy on a small area. Go to a small town butcher and talk to him about it, he'll probably even be able to set you up with some flesh and bone for testing.
Former machinist and manufacturing engineer. There's a lot of cutting physics at play here - one of the biggest ones that I'd immediately fix if this were a machine I was working on is the carriage rails. A good rule of thumb is you want the length of the bearing surface a least phi - golden ratio - times longer than your maximum span. This provides the counter-moment to keep the crossbar from twisting. If you are expecting huge forces, you want the cutting point as close to the rear of the bearing surface as possible - this forces the carriage to align with the cutting force for the same reason boats float. Second, the anvil is important. If you want the absolute maximum performance out of a chisel-style blade, you have to imagine it like a pair of scissors. The bottom shear also needs to be sharp, even if it's 90 degrees. The blade should smoothly engage with the anvil before it makes contact with the material; this is why big industrial shears are shaped like scissors. It keeps the shears in contact with each other so they can't cut into one another. Important to this, the shear gap - clearance between the blade and the anvil - is critical. Too small of a gap dramatically decreases cutting performance, as the viscosity of whatever's getting dragged into the gap provides more friction than the cut force. Wax handles this really well, because what you're actually doing in a wet situation like this is forming a hydrodynamic bearing between two hydrophobic steel surfaces. With wax, you can just spray water and it will perform as a lubricant.
This for sure. The lack of tying down the mats (weren't people restrained and placed in those locks? Sure, mostly because people are gonna squirm when youre trying to kill them, but also to prevent the mats from rolling as 7kilos of razor sharp metal drops on them in freefall) kinda irked me, but the acknowledgment of flawed procedure and further testing is heartwarming - ironically, given the macabre subject. Always nice to see good science being done! Not that I expected perfection for such a laborious, expensive experiment to begin with. I wish I could test this sort of thing myself! (Another medieval device I wish I could build/test irl: Trebuchets/Mangonels.)
The Brachistochrone curve should be pointed in the middle with curves going outward from the middle on each side just like the pointy blade. That would make more sense since usually the object being cut doesn’t start from one side but rather from the middle.
#1 no head hole, a real guillotine has a board with a hole that prevents the neck from moving to the side. Without it the cut object moves away both losing energy and eliminating the slicing effect from the blade being angled #2 bracing the rails in a few places to make them wobble less. You can see the wheels losing contact, this lets the blade come in at an awkward angle and makes it easier to hit the wood. #3 using a very thick sausage with a skin like a giant salami/mortadella would be a good idea because its internal structure does not slide about so much and it has a skin. Maybe even wrap it in pig skin for better effect. Having to cut the skin does make it more difficult and an exceptionally bad blade design would be more likely to achieve crushing damage instead of a cut, because it will mash all the interior but won't go through the skin. There are about neck-thick mortadellas and salamis but they are expensive.
The guillotine you showed from the museum, was of equal width, not having the issue, of imbalanced weights, while in your prototype you use an entire right-angle triangle,e which makes it bend, so yeah try the. one similar to the museum for better accuracy, great work btw.
While the Imperial Bald Eagle is still the most common unit of weight and mass in most of the US, in industry, we've been using decimal B.E. since WWII. Not quite as modern as the Dutch Decimal Lion, but it gets the job done.
You may take note that the (potentially used) guillotine blade is much wider, and it's carriage was probably not a set of complex rollers and what looks like 3D printed plastic, but a frame or two pieces of wood fitted to the ways of the frame. Yes, this will result in more friction losses than rollers, but it would also make it impossible for the blade to significantly turn aside from the cut. You can torch blacken and then sand and polish the frame to make it's surface a bit smoother and harder than the sliding blocks which will help to prevent binding and friction. *Edit, the tatami mats you were using are best at simulating flesh when they've been left to soak in water for some time, tie the ends of your test piece together tightly with chord and soak the whole thing in water for a good amount of time before cutting it. This will make it expand and build some tension in the fibers which will make it as flesh-like as a mat of plant fiber can be.
I like how you do ad reads, it surpasses the rest by making full use of your screen rather than stopping the whole video for said read. You also use sponsors as comedic relief using adam and ev- ahem, i mean through ingenuity
One flaw is the Mass is not fixed, so the potential energy is higher and also it's inertia. Also I think the original is angled because it allows one side of the blade to slot in between the wood thus aligning it to not hit the wood.
Mass is constant, all blades are exactly 10 kg. Proper Printing emphasized on this and showed how they added ballast to bring mass deviation to under 100 grams.
@@josgeerink1350 Any blade shape can be slotted into tracks along the edges, the thing with the slanted blade is that leading edge is the part closest to the track, thus the part subject to the least wiggle.
@@cal593 1000 kilogram is when you have 264.172 gallons of water, cuz 1L is 1000 grams which equals 1 kilogram and 1000L is 1000 kilgram or 1 metric ton. Also 1111 1/9 9mm bullets next to each other equal 1m in length, 1 cubic meter so 1111 1/9 9mm bullets in Y, X and Z axis equals 1000L of volume.
You forgot a shape. The inverted pointy. Like an open pair of scissors getting slammed down that will focus the cutting power inward towards the middle.
And in the middle it'll crush I guess. The pointy forces outward forcing cracks or cutting, inward makes it crack or crush. Let's say it makes the target material denser and denser stuff is harder to cut
The catchment at the bottom that the blade slots into doesn't need to be very close together. You can easily fix some of the wood-hitting just by moving those further apart. (Though, that may mean making the carriage a bit thicker). Can't wait for round 2!
As someone who has built industrial guillotines, I can tell you, you need to make the carriage taller than it is wide (2 to 1) and you need a tighter fit between the carriage and the guide rails. I had to do some experimenting when I designed my guillotines, and found that a 5 to 6 degree angle on the blade with a 15 degree bevel worked best for cutting through the material I was working with - polyethylene plastic. Obviously, the blade needs to be designed for the material your cutting through.
As a future guillotine builder I appreciate all of the work you have done. You have illuminated a bunch of engineering considerations I'll have to keep in mind in the future.
i think you should have fixed the mats, like the heads didnt have space to move as well during those times so it may change things if you didnt allow the mats to move
“Not used all day every day.” Many Frenchmen would say otherwise in times past. Prediction - the highly concave curve will progressively increase resistance, as the top is practically flat. Necks were restrained too. Great video! 👍🏻
Another thing to keep in mind(at least with using tatami) is that the mats are meant to be soaked in water overnight in order to provide a more accurate simulation of a human neck/limb.
When I worked for a commercial press (printing company), they used modern guillotines, which uses a hydraulic piston to press the knife's blade through the substrate quickly, and then then raise it back up again, ready for the next cut.
"off with his head" "ok, let's try a little higher" "damn, ok... uh, lets try the blade that's angled more" "well crap... uh, can you just, uh, you know, push it through? no? ok, i guess go even higher"
I appreciate the fact that you actually read everyone's comments and noted their suggestions. Most youtubers with a channel of your size do not go through that effort.
I think main issue with the angled blades is that unlike historical guillotine, you didn't secure the mats as their necks would had been. so it kept sliding to the side which lost A LOT of energy.
its amazing that this guy can speak perfect english without having a terrible accent, AND STILL speak dutch also without a accent, teach me your ways ALSTU
Suggestions: 1. Make something that holds the thing in place so it can't move as it's being cut. 2. Make a bigger hole for the blade to go through so it doesn't hit the wood. 3. Make the blade wobble less, this can be done by increasing the length of the gantry.
if there's too much weight on one side with angled blades, the fix is simple. add enough weight to the light side balance it out. This will keep the blade straight at least until impact. To avoid the blade tilting on impact, you could add even more weight to the light side, but then the blade would tilt in the opposite direction during the fall. You partially did this when you added a piece of wood to the flat blade to compensate for weight difference, but instead you'd have to account for how much extra weight is on the heavy side, to add it back to the lighter side. If all blades are to be the same weight, then you'd have to recalculate how to cut the blades, so that you can add the extra weight after you have the blade shape.
Don't forget that when those Old Dewds would cut your neck off, you'd put your neck in a rounded trough, and a matching piece would slide down on top to act as a collar, fixing your neck in place with little room for movement. That would 1) keep your neck from rolling/twisting as any slanted blade would apply torque, and 2) keep your neck from sliding away laterally as well. The mats in the test were free to turn and be pushed aside, which is probably what screwed with the readings. Even fixed pegs on either side holding the mats in place would help prevent that.
The Guillotine saw two brief periods of extensive use. 1793-1794 during the French Revolution around 17,000 people were executed with it. Nazi Germany used it to execute around 16,500 between 1933 and 1945, 10,000 just in 1944-1945. The last time anyone was executed by Guillotine was Hamida Djandoubi (on 10 September 1977) in Marseille. There were vertical head chopping machines prior to the Guillotine, notably the Halifax Gibbet (a replica was built on its original site) and the Scottish Maiden, of which the original constructed in 1564 is on display in a museum.
I'm late to this party so people have likely pointed out these things: - carriage rotation will add friction, which is likely significant - mat motion wastes energy as well - tatami mats are really about testing the skill of the cut, not the sharpness of the blade. The skill of the cut in this case is fixed by the frame. Though these results suggest that you can still get a valid comparison
One of the parameters you need to look at is how large of a piece of metal can the blacksmith fit in his forge…..Armorers worked in thin plates that were larger, but for a blade that size and thickness you need a smithy, and his equipment would limit the size of blade that he could handle…
First watch of your lecture and I am in. I really like how you bring the assumption of some technical knowledge but still use real examples. Thank you kindly for sharing.
I think that the shape of the object you're cutting has a large impact on the theoretical performance of the blade. If you're cutting a circular object it probably doesn't matter if the blade is angled or not, since the impact point will be tangential to the circle anyway and will result in a similar sized interface between the blade and the thing that's being cut. If you cut an elliptical item however a straight edge coming from about will have a much larger impact area than a slanted edge. If you try to cut a triangle pointing up it will probably be the opposite, the flat edge will hit the point of the triangle while an angled edge would hit the side of the triangle, leading to better results with the straight edge.
Interesting exercise. If you're only interested in blade design, I suggest a VERY robust, rigid, low-friction, metal frame with a lubricated metal slot in which the blade travels. Use a long, symmetric blade frame designed to minimize blade rotation for asymmetric blades. And a semicircular well or adjustable side constraints for the mat bundle to prevent lateral movement of the target. Also make the blade slot under the target wide enough that the blade NEVER contacts it. If you want to get geeky, interface a 1000g accelerometer to an Arduino and read it at about 10kHz.
Here's an interesting historical tidbit I once read. Dr. Guillotine, after whom the device was named, was researching methods to replace the headsman's axe, that would perform consistently and be more humane. He discovered the device, that would bear his name, in an old document from Eastern Europe. It had a straight blade. King Louis VI checked out the doctor's recommendation, and had a suggestion. Why not angle the blade, to make it cut more efficiently? So, that was done. Regrettably, the King was, some years later, given the opportunity to PERSONALLY experience the effectiveness of his suggestion! 😩
People already addressed your apparatus problems, and much better than I could. I think you should also add a convex brachistochrone blade. Most weapon blades (and modern tools) designed for slicing used convex cutting edges
I was about to come into the comments and say something along the lines of "as per the cutting theory explanation you provided earlier in the video about how slicing with a horizontal motion creates tension in the material which makes it easier to cut, a reason why the angled blades didn't perform as well as expected is (I assume) probably because the mats were rotating as they were being sliced, reducing a lot of the tension from the mat as it's being cut, whereas someone's head is fixed in place in a guillotine where it cannot move like that, therefore tension is maintained throughout the entire cut," but then I see that many people have already said something similar haha
There is a couple of things that I can add that, while not necessarily helping or hindering your results, will provide extra consistency to the results. First, tatami mats, when used as a cut testing medium are supposed to be soaked in water. This will soften and tighten the fibers as well as making them much less likely to just break when pressure is applied. Second, the mats need to be bundled tightly and bound so that they don't unroll or unravel under the pressure of the blade landing on them. Unbound and loose as you had them here, the spread of the mass of the tatami could move around making some portions of it easier to cut, and being that they were dry, it made the whole thing easier to just break rather can be cut properly. It may only provide a minor difference, but in science, consistency is important! Hope this helps.
My first minute theory. Try to cut a tomato by pushing a knive through it, then cut the tomato by "gliding" the blade into it. Which works better? That's what happens to a neck if a blade was just dropped on it versus glided through it - which happens when the blade drops at am angle. A lighter/smaller blade is needed, less mess created, the blade stays in a better sharper condition.
A few Tipps to make a better setup: - I assume that you are aware, that the neck to be cut was fixed in place? Not just to stop people from rescuing their neck, but also to minimize movement of the material which bleeds off the cutting force. That is a big problem, especially with diagonal blades. - Oftentimes Guillotines also only had one side where the blade could get stuck. Which was also the side that held the head in place. No need to make it fall into a slit, just remove one of the boards. - Or put the material not at the botttom but elevate it enough, so it gets cut, befor the blade can hit the bottom - As far as I know, quite a few of the Guillotines were set into notches along the sides, so when they fell, they literally could not move out of there. It was getting the notches the perfect depth so that it could not wobble or get stuck, before first assembling the guillotine that was the problem. - Last but not least, the idea about dulling prevention by making diagonal blades was decent but not thought out enough. What dulls the blade is not just cutting the material, but being stopped by cutting into wood. Do that a few times and they can start lose their edge. Being diagonal makes sure, only the useless end of the edge gets stuck in wood.
You need a "wet" sample, i.e. meat+bone. They were cutting a human neck, muscle tissue and bone. The theory was a slicing motion cuts "meat" better than hacking. And as executioners have stated in memoirs, " we always tried to place the blade in-between the vertebrae for a clean cut"
One thing I'd point out, is even without the neck being secured with a stock addition, because the head and neck are also still (for a short time) connected to the rest of the person's body, their bodyweight and position and internal skeletal structure would prevent much rotation or movement at all. Part of me thinks that the main reason for the blade being angled is partly down to the fact it was the simplest blade type that was able to be made by the blacksmiths of the time, partly down to the fact they were thinking of the blade on similar terms to that of a sword - where the sword slashes and drags across your target rather than flat impact like an axe (and executioner axes were often angled/curved blades or they swapped out the axe for a sword because flatter more "lumberjack" style axes had proven to be ineffective at decapitation in a single, smooth strike). There's also the fact that neck muscles are extremely tough, as are the tendons securing the skull to the spine and the spine to the shoulders - they have to not only provide movement but structural support for what is a rather heavy lump of weight atop a rather slender support "column" - AND they have to compete with the incredible pressure of the arteries supplying blood directly from the heart to the head. So causing the initial cut away from the spine and then moving it across as the blade descends is likely the best way to smoothly and quickly decapitate someone. Your pointed blade did well against the matts, but would likely be stopped dead if it struck the bones of a real spinal column of a realistic neck.
A major problem is obvious! Guillotines used for execution had a cross-member at the bottom, with a hole that the neck passed through. That prevented the neck from being pushed sideways, away from the blade. A simple board, butted against your test items, would work, just as well.
I just imagine you, wearing 18th century clothes and a powdered wig, explaining a critical Robespierre in this voice the benefits of your blade design.
There's also the lateral translation of the material when struck by angled blades. You're transferring downward momentum of the blade to horizontal momentum of the entire weight of the mat. In a real guillotine, the "neck" is held in place by a collar, so that it can't be "squished" to the side.
I have my suspicion for why a higher single angle blade would work "better". If a portion of the blade is down into the slot underneath before seriously cutting it would be more consistent at staying on track front to back, and if you hit the base with the blade you may risk damaging the blade catastrophically. This means that while you may get rotation from an angled blade, it does not deflect front to back as much, which may be more relevant for consistent function more than for individual optimization. Also, if the blade stops on a board rather than continuing through, the odds that some portion of flesh or skin is not severed may increase, especially as those materials can deform without cutting more than a straw mat, which would make a flat blade that missed the slot look like a botched execution despite being just as lethal. My suspicion is that consistently "following through" into the slot is of greater importance
