Why are Guillotine Blades Angled? We Built One to Test it!

[@properprinting]

If you have any suggestions on how to improve the design or what to use a testing medium, please leave a comment! Also, check out voxelpla.com/properprinting for some affordable and reliable filament!

[@fixifaxhd772]

Currently you are trying to keep the blade straight by clamping it in between the two wooden support beams (inner edge). What if you try to attach it on the outside (so the outer edge). I'm not sure if it would actually make a difference, but I feel like it would reduce the amount of wiggle room.

[@runo9]

on the angled it seemed like the matts were rolling away from the blade

[@CallmeSam00]

Your carriage seems to be creating a large error that probably is so strong that you're not reliably measuring anything else. A longer carriage would reduce the error, but deflection braking would probably still be significantly bigger than any other effect. instead of adding rigidity and optimizing mechanical lever proportions on your device, how about going the other way and removing parts but adding mass? a much heavier blade that free falls between two smooth beams per side will mean that inertia is the stronger factor above deflection from the blade shape and it will not as easily bind with the linear carriage you made.

[@properprinting]

@@CallmeSam00 Thanks for your suggestion! I think that you're right on adding mass. Yet, this poses a similar problem we ran into when dropping it from a greater height and that is that it becomes increasingly difficult to find the differences between the blades. I think that my biggest failure is the carriage system itself. It is too short and the angled rollers make things worse.

[@ZappyOh]

@@properprinting I found my old drawings from 2016 ... do you want them?

[@gaveintothedarkness]

Remember, it's only a Guillotine if its from the Guillotine region of France. Otherwise it has to be called "Sparkling Head Separator"

[@mikeyearwood]

That's brilliant!

[@NicksStuff]

I get it and it's funny but it's a guillotine because of that dude: fr.wikipedia.org/wiki/Joseph-Ignace_Guillotin Funnily, he didn't invent it and fucking hated we gave the machine his name.

[@DarthTater5738]

You can see why the old blades were so long. A blade that long can not tilt in a slot very much.

[@properprinting]

Good point!

[@gapho5198]

I always assumed it was because for each step horizontal compared to each step vertical it would be more effective in "chopping" Like how daggers create deeper wounds than swords for slashing, but sort of combining the two, for "deeper" "slashing".

[@NathanBuildsRobots]

@@properprintingthis is exactly right. Any sideways force introduced to the blade produce a moment about the center of gravity that will tend to tip the blade. This force must be reacted by the guide rails. The moment about the center of mass must be opposed by a moment couple. I can provide a free body diagram if needed that can be used to calculate friction losses along with some articles on preventing binding on linear guide systems Happy slicing!

[@myopinion69420]

13:48 haha, headroom, for a guillotine, isn't that just a basket?

[@sn0opyKS]

🥁

[@Onni-]

The rusty cage arc is starting

[@akosv96]

Dude, just wanted to say the same.

[@properprinting]

Damn, TIL about Rusty Cage...

[@PleakeCrions]

Haha I thought this was a collab with him

[@Deses]

It's crazy that he did that.

[@Onni-]

@@Deses nah not really

[@dedompler]

Man, everything looks great and this was a joy to watch! Some further considerations for the sequel: 1) At some point, the blades will need re-sharpening and close inspection to ensure uniformity and fair testing 2) You can purchase pre-rolled tatami from Kageyama or similar makers (import might be pricy) and wet them per the instructions; include the center wooden dowel to increase rigidity and improve its function as an analog to a limb or neck by mimicking bone. This will act as proof for building a carriage the doesn't twist/deflect on impact, certainly more effectively than loosely rolled & dry mats. For what it's worth, reliably measuring cutting performance is tricky to accomplish even in the most controlled testing scenario. I don't have any other suggestions for now, but I'm confident there's a more consistent medium for this purpose that isn't prohibitively expensive. You might also consider securing the mats in a fixed position on the cutting bed to prevent any discrepancy between height tests on the same blade. 3) The top-down camera angle is sweet - obviously it'd be a bit less shaky if its mount was isolated from the guillotine frame itself (perhaps the ladder?) Other than a few small nitpicks, the overall build and testing methodology is superb. I'd have given up after the first hour of grinding abrasion resistant steel 😂 I very much enjoy the fact that you and Aldo resolved to say "hey, our testing isn't quite strict enough at the moment and there are parameters we don't have complete control of yet - we'll be back!" This gesture alone means you should retain a majority of viewers from the first video and potentially gain many more on the second. Venturing to speak for many, we were curious - but now we're excited! I'm pumped for the next one, good luck and stay safe fellas!

[@properprinting]

Thanks a lot for this awesome comment and your suggestions!

[@MichaelTavel]

Dude, SO MUCH SUPPORT MATERIAL! It was a 45 degree angle and probably would have printed fine!! (Signed: Certified internet expert who wasn't there and hasn't seen your detailed design)

[@NicksStuff]

As a frenchman, I enjoyed this topic very much 😬 And I can't believe I didn't visit the museum while I was *living* in The Hague, only 700 meters from it! Maybe it wasn't open back then, though?

[@timplett1]

Make your carriages taller to increase the distance between the wheels. The further apart the wheels are vertically, the less twisting you will get. For smoothest operation the wheels would be spaced further apart vertically than the distance between the two sets of wheels horizontally.

[@rvandepo]

Distance between wheel on carrier is larger than distance between beams

[@woodworkerroyer8497]

Either you're saying that the wheels are currently further out than the beams are, which is obvious, and irrelevant, or you're saying that they need to be and that's why it's tilting. The wheels are wider than the posts, but they have to be in the current design. Making the wheels farther apart VERTICALLY by lengthening the carriage wouod solve the issue. Maybe that is what you meant?

[@SianaGearz]

You can make a lot of money buy selling guillotine frames at a discount and then racking up the prices for the guillotine blades. Of course the guillotine would only be FDA-certified when used with original blades. It's the perfect business model really.

[@mrkrusher29]

Have you tried tightening the eccentric nuts on the Z-Axis gantry? Common problem on Creality guillotines

[@ZappyOh]

I designed a guillotine back in 2016. Could be built by two men over an extended weekend. Would only cost around €400 for everything. Nobody wanted to help me build it, but I still have the drawings somewhere :)

[@ZappyOh]

PS: My blade was exactly like your pointy bonus blade.

[@MumrikDK]

"Wanna go to the cabin and build a guillotine, just the two of us?"

[@andan2293]

Don't worry, your time will come!

[@AdrienRochereau]

extend the height of the carriage with another set of rollers higher up to prevent tilting

[@theboss2k]

I can confess this is my favorite guillotine KZbin channel

[@stevekreitler9349]

The simplest reason for the guillotine to have only one angle to the edge is that they were made in the 1790's. Iron was reasonably priced, and relatively easy to work. Steel was expensive. At that time, axes had iron heads, with a strip of steel welded on for the edge- an exacting and difficult process, and only doable on a straight edge (pretty much). Doing this with something as large as a guillotine blade would have been very difficult, and thus kept as simple as possible.

[@TurboSunShine]

Nice video! Looks like the slide got pinched when using the 30/45 deg blades. And maybe the target body needs to be considered to avoid deformation during cutting? Looking forward to part 2!🎉

[@properprinting]

Thanks! I think that I made the wrong choices with the carriage design by placing the wheels and beams at that 45 degree rotation. Next version will be much better!

[@AndrewAHayes]

I think they used the angled blade as there is a minimal amount of blade touching the neck as it drops, and the blade that is touching is cutting a minimal amount of flesh as it drops.

[@felixm.8910]

That was such a fun video. The skits in the beginning and the end were delightful humor. I think making the carriage longer would help in giving it more guidance, since it cannot tilt as much. Also using thicker beams would help to reduce the bending-modes of the frame, I think. Otherwise maybe making a beam that connects the frame halfway up the rails (as you did with the strap) would keep it from bending towards each other.

[@PaulLemars01]

The standard neck analog as far as the Japanese are concerned is a saturated rolled up tatami mat. I can't think of anything better than that. And use thicker wood sections.

[@woodworkerroyer8497]

Here I was thinking my LTT screwdriver was expensive! That metmo one competes with PB Swiss LOL. Looks amazing, though!

[@MatthewMcilwain123]

I find it somewhat humorous that the packaging for the blades designed to test the optimal form of decapitation with a guillotine was opened with a box cutter that is optimally designed for cutting packaging. The box cutter uses very similar principals as the long standing representation of a guillotine, there are even brachistochrone styled box cutter blades.

[@markwebcraft]

Making your own wood beams for this project? I guess you really wanted that authentic feeling lol

[@Jowbreak]

Geen expert hier, maar volgens mij is het verschil tussen haaks en onder een hoek dat een haaks blad hakt en een blad onder een hoek meer snijdt. De manier van slijpen zal ook wel invloed hebben. Je zou eens wat kunnen opzoeken over Japanse messen/zwaarden, die staan er om bekend dat ze zeer precies en goed snijden. Een guillotine heeft ook altijd een houder voor het hoofd, dit zal ook helpen te voorkomen dat, in jullie geval, de matten weg kunnen schuiven en zo de kinetische energie van het mes absorberen. Ik vermoed dat het fixeren van de matten dus ook invloed heeft op de resultaten.

[@Enjoymentboy]

The opening was perfect. You had me hooked within 20 seconds and now it doesn't even matter if I like the rest of the video or not. today is going to be a good day.

[@MerkNation]

Why is no one talking about the end when its implied they guillotined the chickens and ate them xD that was hilarious. Between that and the support asmr, and of course the general content, this was an amazing video!

[@aure_eti]

A guillotine and a disclamer at the beginning of the video ... couldn't resist to like it

[@beachwat]

Man we (french) need this delivered asap ngl

Best ASMR that I've ever heard, want more in my life

[@p-thor]

Is that the prusa enclosure for the XL? Also a missed opportunity to do a proper skyrim intro with you sitting in the back of the cart of the tractor.

[@superhans3717]

Production and editing quality always blows me away.

[@troypickett7716]

3:30 slow mo shots give of "hell yeah" vibes

[@fixifaxhd772]

Loved the support material asmr 😂

[@BlakeMaxwellJenkins]

Nice video Proper Printing! You're videos are getting better and better to watch! Really enjoying them.

[@chilliconcarne8828]

Hi, in addition to a vertically longer carriage to reduce tilting I suppose to use a board with a hole (for the neck) to prevent the matroll from escaping sideways. I believe this will improve the cutting performance of all your angled blades. Perhaps you will also have to slightly enlarge the slit in the "table" to stop the blades from hitting the wood.

[@NiksSofa]

"... and no clue of what to do with it." I'd hold on to it, might come in useful in the next decade or so.

[@chuckles1808]

Honestly, for a guillotine blade, you would want a more resilient metal due to grinding against bone and you don't really want to redo an edge on something that heavy. I think it was a fine choice

[@802Garage]

Voxel wild for sponsoring the next revolution, hahaha.

[@makermylo]

Your support removal ASMR is on point! 🤟

[@petervillano3484]

5:00 The grinding sparks flying directly into the wheelbarrow of sawdust 💀

[@Onyxx98]

damn after the guillotine channel (from corridor digital/corridor crew) failed i cant wait to enjoy more guillotine content

[@omega_one1318]

I'm also wondering if constraining the position of the mats might lead to better efficiency. As it is, you can imagine that with an angled blade, the mats slide away from the blade and dissipate some energy this way. By fixing the position of the mat this loss might be minimised. The original guillotines you showed seem to have a similar feature, although that might have been implemented to prevent the... patient from escaping.

[@Deses]

Nice lemonade stand you got there.

[@Metruzanca]

KnowArt in a WHITE dress shirt while cutting lumber is hillarious.

[@platin2148]

For Grinding such stuff i suggest using fiber discs.

[@Roobotics]

In addition to what others have said about extra rollers to prevent tilt, there's a pretty critical aspect that I didn't see addressed yet. *You aren't constraining your tatami mats from sliding about!* Don't let it just scoot around like that, it's also sometimes letting it deform into a large flat plane which will cause inconsistencies based on how the differing geometries push things sideways. My first thought is a large printed or wood U shape beneath, with a large U-bolt from the top punched-through that, to make an enclosed circle and be easy to service, probably doesn't even need to be tightened down, but adds that option also.

[@astralnomad]

"design and execution plan" -- no pun intended, right? ;)

[@adam03110]

I wonder about blade weight , it must matter, as well as hight. and how about an inverted V blade? how would that work?

[@MrSand6532]

seems to me that it was a bit over engineered. medieval guillotines just worked. didn't have to worry about slop in movement because the parts wore down after repetition.

[@iopfarmer]

Inspired by the opening of the Olympics by Gojira? 😂

[@micahegesa2297]

I think the results might differ, if the the mats gets secured. The angled blades might not be able deposit its full energy into the cut when the mats are moving, nor is it able to slice/cut effectivly for the same reason. Worth a try at least

[@bacon.cheesecake]

Great video as always, I think it would help it fall straight if the rollers were spaced further apart vertically

[@andymuzzo8568]

Awesome idea. Love testing all inventions.

[@yokeprg]

Collab with KnowArt? Amazing!

[@faultboy]

Now the only thing missing is a queen that is hated by the people...

[@chris993361]

I think the biggest thing you can do to control tilt is probably separate the wheels further vertically (taller carriage). It may also be that adding another set of wheels front to back (thicker carriage) may help with the front to back tilt that causes the blade to hit the wood. Just my initial thoughts on seeing the deflections.

[@TheRealAlpha2]

Reminds me of that time Corridor Digital had their own Guillotine channel. I think yours is better made. More simple and seems to just work better because of it.

[@BeardedPrinter]

You get a thumbs up just for those sound driving effects

[@BadgerBishop]

A longer carraige would make the wracking less of a problem. Add a 3rd wheel with the same spacing as tye first 2 and it should make a world of difference.

[@PMcDFPV]

It would be interesting to use one of those sharpness testers and see how sharp your blades are.

[@DrJimBoston]

Print two more red things for weels and make wooden board longer. Tilting won't be such a problem anymore, and weight won't change a lot.

[@johnelwer3633]

As a woodworker, I'm hurt you didn't use mortise and tennons for the joinery. But not as hurt as that watermelon, eh?

[@russl7128]

First 30 seconds is GOLD🤣🤣

[@NobleValerian]

I like that little Suzuki. But it reminds me how many cool vehicles we never see in the US, or eventually see at a ridiculous price point. 😢

[@bomdia...comcafe]

REMEMBER, NONE ANIMALS ARE HURT IN THIS VIDEO

[@michaelgonzalez8863]

A cinematic beauty

[@Flubber2.0]

You could also put rollers on the outside of the rails like rollercoasters have

[@petervillano3484]

You could solve the clipping by putting the phone on springs. Heck, you could measure the peak force by mounting (to the blade) a marker on a weight in on a spring in a track

[@themistoklisanastasiadis]

i was hoping on a reverse pointy edge... oh well. great video as always

[@forsthorst01]

Best Channel on KZbin! I love your Videos!!! 👌💪🏼🎉

[@cherrytree3400]

can't help but wonder how well a reverse of the pointy blade would work (as in a ^-shaped edge instead of a v-shaped one), although a shape like that may be hard to sharpen

[@pienasty]

Start a new channel, daily you release a video of 1 random thing being cut by different blades in slomo. I'd watch all of those, please I need it NOW :D

[@zfrenchy1716]

do you know, in France, at the time the Guillotine was till in use, if the execution failed, you will be pardonne. Not sure in what condition will will go back home ? but for the history, the Guillotine never failed. In one case, in 1831, the blade was raised 4 times, jamming in the rails, before the convict loose his head at the last down !

[@RoboCNCnl]

Next time don’t laser… contact me 👍🏻 cool project guys !

[@FrozenDozer]

Corridor built a guillotine a couple of years ago and if I remember correctly they pretty much ran into the exact same problem of the blade / sled just wedging all the time. Channel is "Guillotine Channel" if you want to look it up although I'm not sure if the video of them building that thing is on that channel or on Corridor Crew.

[@bacon.cheesecake]

19:15 that screwdriver really reminds me of the weltrekord that my mechanics restored, and which i designed and printed a shitty replica of

[@Sponge1310]

I think the distance between the sets of wheels on each side of the carriage should (at least) be bigger than the distance between the two rails (width of the guillotine), to prevent the blade from ‘twisting’ and getting stuck or being slowed down by friction? Anyway, awesome guillotine, there must be loads of random stuff that would be entertaining to see being cut by it 😎

[@BloodyMobile]

Text: "Support removal ASMR" - Audio: plastic massacre with heavy metal nice

[@mattskolnik4513]

I also keyed in on that, but… Where was all the bloodshed?!?

[@NicksStuff]

I would try to angle the bottom (with the edge) and the top part of the blade the same, so that it's balanced (i.e. not heavier on one side than the other)

[@generalfishcake]

What about 4 separate rails guiding the guillotine from the front and back, not from the sides? It will tilt, but not wedge itself in the wood & slowing down the blade.

[@destroyer1675]

Could you try test a U shaped blade next. In theory the curves on each side will guide the obstacle to the center of the blade and not deflect like the non-flat ones did in the video.

[@imjstcl]

Id think having the rollers far apart, or even having 3 sets each side would certainly help. I dont know how much though. Also although your phone data is clipping on impact, it could at least tell you if theyre all accelerating the same or if some are having a lot of friction on the rails right?

[@kaizoor]

Hopefully the watch is also listed in the gear

[@Beaujamin]

Love it. 🤘

[@scorch855]

The wheels are vertically too close together which allows it to twist easily. Try adjusting the carriage so the wheels make a square around the whole blade rather than a small rectangle at the top with the majority of the weight hanging below it. This would also help better align the blade so it doesn't collide with the wood.

[@devjock]

"You wouldn't download a Guillotine?!??" [Looks at the politicians ruling over us in the same city as the museum with a guillotine as a centerpiece] Yes, yes I would.

[@dedompler]

15:08 Thank you. My ears needed that. Was it pure coincidence, or did you measure the BPM and find tracks to match? Either way, loved it

[@properprinting]

Thanks for noticing that! It was a coincidence, but once I found out that the BPM's matched, I made sure that it was aligned perfectly!

[@NicksStuff]

On the shape of the blade, I think I remember from my history lesson the first had a convex banana shape if you wanna try another one

[@Reds3DPrinting]

total missed opportunity for a funny *bagawwk* from the chicken

[@properprinting]

I should've done that and ended the bagawwk abruptly halfway at the moment of impact🤣

[@weaponeer]

For a good running vehicle in good shape, you can take off my hand.

[@davidcoulombe2000]

Vroom!! Nice effect!

[@davidcoulombe2000]

my guess would be to elongate the rollers parts and put more wheels on it. Maybe, even n angled wheel shape for the corner. Why not a tank track for that corner wheel? Nice work though!

[@richardha2]

Awesome!!

[@MadManWIll]

Did you tell the museum you were going to make one? and that perhaps it wasn't just for educational purposes?

[@cillianennis9921]

I think you should try to copy the historical examples better. So if you held the material in between some wood like the real ones did you'd have less rolling of the material. & then if you put the rest for the blade a wee bit below the point where you are cutting the object like historical ones seem to do you will avoid the wood problem. For the turning its likely you want a more secure housing like historical ones. I think the one at 0:49 in the video shows what I mean. You might be able to find some archived blueprints for one that you could copy somewhere as they only went out of use in the 70s so there should be a semi-modern depiction of how its built. edit: after watching this video (since I watched the other video 1st) I think I am slightly off on what I mean by the wood thing. So I think the blade housing is just being held in by friction basically & relies on rough indents in the frame to keep it from going to one side. Maybe you could fix the design by adding a counter weight or something.

[@anoukk_]

How do you measure the starting height of those angled blades? I feel like that is pretty important since the end of the blade is further down from the carriage meaning the fall distance is different.

[@properprinting]

Good question! Aldo explains that perfectly in his video! We rested each blade on the roll of mats and measured from there.

[@p-thor]

Daaag lekker kippetje 😂 nuggets anyone?

[@scott5017]

Rollers on the outside of the wood should help keep it straight no?

[@Finchyboi14470]

If I had a nickel for every KZbinr I’m subscribed to that’s decided on a whim to build a guillotine, I would have two nickels, which isn’t a lot but it’s weird that it’s happened twice.

[@adrienkerguelen1913]

We currently have a president who thinks he's a king, if you ever want to test it in real-life conditions. After all, that's our French history :D (This is a joke, not a real proposition)

[@chaugan]

$63 in shipping for the VOXEL filament. That's a hard no.

[@SanderMakes]

(before watching the video) Hmmm I guess the custom printer project isn't going well? Guess someone needed to vent some frustration? 😜