The final build looks like something out of a Cyan Worlds game that would be a little in universe flavor to learn the numbers of a fictional written language.
Actually, if you cover the disk with thin aluminum sheet, so individual magnets are no longer visible, it will be even more satisfying and "mysterious".
Since you just want random numbers and don't care about them being arranged sequentially in the spinner, you can overlap the positions and reuse magnets from the previous position for the next one. EG 2,3,5,6 and 8 all have three horizontal segments so you can get away with just one set of magnets to flip them on for half the wheel and then another set to flip them (as needed) in the other half of the wheel. You can also take advantage of the fact that the top half of the vertical segments are the same in 2/3 and in 5/6 whereas the bottoms are the same for 3/5 and 6/8. Meaning you just need to encode which bits to flip, not the whole state of the display per position. And, by just encoding the flips not the full data, you can cut down drastically on the space needed in the wheel.
I like this line of thinking, but I can't help but think that there would be some inevitable failure in the magnets flipping every node every time, at least when the disc is spinning fast. The one nice thing about parking the display over a full array for every number is that every node lands on a magnet that ensures it reads correctly. And having the same number of magnets on every number also helps balance the weight and spinning speed to reduce bias. I would think since magnets determine where the wheel stops, having more or fewer on different numbers could make them more or less likely to appear. I could be completely wrong though.
@@shotguntornado if you have a reset field (all on/all of) maybe it could be enough. Because in the end you only care about the correct flips once it slows down. And you should already have the bias in the wheel as it is. The one that has only "repellors" should be more unlikely than one that has only attractors or do the displays not work like that?
Won't that mean it only works in one direction, though? Since a magnet doesn't "flip" a bit, it's specifically writing a 0 or 1. If you set it so going from 6 to 8 just entails activating the top-right pair, then going from 8 to 6 will only keep them on.
@@SollowP I didn't even consider that, yeah you can't just choose to flip a left or right side. You can't flip a 3 into a 5 without it becoming a 9 for example.
@@m1geo Probably just straight up burning. It's a cermet, there isn't any aluminum metal in the magnets. That wouldn't work since they're sintered! It's just straight up burning, for a thermite reaction you need an oxidized metal and a metal that wants to pull the oxygen. Rust (iron oxide) + aluminum = pure iron + aluminum oxide + heat. There is no oxidized metal in a neo magnet, so it can't be a thermite reaction. That means it's just straight up metal fire :) I mean there is a tiny amount of aluminum used probably as a flow modulator and plasticity enhancer during the pressing, that just kinda does nothing after sintering, but you aren't getting a thermite reaction with .2% aluminum. It's just normal combustion oxidizing all the metals
@@dogsarebest7107 "Probably just straight up burning." Well, it's glowing. The drill bit would melt long before reaching the temperatures required to ignite the metals in the magnet.
@@vinny142 No, definitely not. That's a tungsten carbide endmill. They happily turn steel into burning shards, happily turn titanium into raging fires, what makes you think it won't do it for this? It has to do with PHYSICS. Small particle size means LOW THERMAL MASS and HIGH SURFACE AREA. That means it burns REAL EASY. Why do you think microscopic powder generated is HARDER to ignite, than a solid chunk of tungsten that weighs several ounces? Even ignoring the fact that one particle igniting, generates heat that then raises the temperature of adjacent particles to either very near, or above the autoignition temperature. That's how exothermic reactions are defined. Have you seen any machining videos? Never seen a spark happen? Never see ribbons of metal burn? Touch a 9v battery to steel wool and think about it Static electricity can happily ignite aluminum powder or titanium powder, but the spark doesn't vaporize your finger. Because.. physics.
This is an incredible project. I have a deep affection for those mechanical flip displays, machined metal, and random number generation. Really a perfect storm for me. Thank you for your fantastic content
this got me thinking about how cool it would be to have a revolver where the cylinder has the magnets around the outer circumference, and have the display mounted on the top. would be fun to play a western style game, pull out your revolver, give it a spin and have the 'roll' shown to you. add a little flair to your roleplay. especially so if your rolling D6s for damage since many revolvers are 6 bullet capacity so it would really be fitting
I love projects like this. They start with just a question or curiosity and then morph and materialize out of thin air. No one asked for this specific thing. Not even you. And yet, now it exists, and it's AWESOME. Love it.
Nice build! Regarding the cylinder + magnet channels idea, at 04:25 you could tilt the display about 18° clockwise (or 12° CCW) to have the Y positions of each magnet be somewhat equally spaced, and it might be possible to design a cylinder where the 7 magnets for a given digit are not in a straight line, but in a weird pattern that matches the exact position of the display. It's a bit difficult to explain but I can sketch something if you'd like :) smaller magnets in the cylinder would probably be required (and a ton of magnets if you want a d100)
You solved two problems (percentile is just two of these). You only need a single bit display to extend it to a d20, as many early d20s did double duty before the modern d10 shape took hold. They would have 0-9, and 0-9 again but with a dot. If you were using it as a d20, the dot was worth 10. If you were using it as a d10, you ignored the dot. In your case, perhaps use a second digit that either underlines the number, or doesn't. Then the viewing window could hide most of the extra display and you're only adding one magnet per number (although twice as many numbers). If you build a d20 disc this way, it can double as one digit of your percentile die so you wouldn't need a second d10. You could also use it in conjunction with the d10 to speed up that Eldritch Blasting. Similarly, you could make a dual-purpose d12/d6 spinner, and a dual purpose d8/d4 spinner.
to be fair I started at lapidary, cutting open geodes and agate, a wee touch on jewellery making and then the algorithm decided it was dice so I had people carving dice on diamond wheels casting them, all sorts. even just some showing off dice. now the algorithm has brought me back to machining just with more dice. cool video dude.
Oh how I wish i could find one of those 7-segment displays for myself. 2 weeks searching and no luck. I would love to have made one myself out of some laser cut wood for my D&D kids. I absolutely love this and would love to see how you would tackle a D20.
Great video! If you want to ream a hole oversized with a nominal reamer, you can shove a greased-up paper towel wad into the hole. You'll manage to oversize it by about 1.5 thou. If you need a little less slip, if you run it at a higher RPM and feed more slowly, you can shave off a bit less. As with drill bits, you'd be surprised how a reamer can be manipulated!
the thing I like about your channel is that you just do what you think is intresting and fun without worrying that it may not perform the best on youtube or other stuff like that
Ack I'm sorry I missed your booth at Open Sauce. Hope you had a great time. I think this project is very understated in terms of all the cool design decisions involved in creating the spinner. Keep making cool stuff!!
You can still do press fit magnets in a drilled hole, but you can't use pressure. It's counterintuitive but if you chill the metal the hole will get larger not smaller. If you chill the metal sufficiently it's effectively and largening the whole big enough to accept the magnet without any serious force and then the magnet gets clamped when the metal warms back up to room temperature. Chilling also doesn't damage the magnets that way. You might be able to use dry ice to chill it, but I'm more effective mix might be liquid propane.
I would love to see a miniaturized version of this, maybe of a handheld size. Of course, that would mean that an even smaller flip digit display would need to be made as well.
Really cool project. Your last video about the map/clock and this one were such pleasure to watch. I like that you don't hesitate to get in to the details without getting stuck to any particular step for too long. Subscribed!
I think when you heated the metal with a gas torch you took it past the curie point which messed with its magnetic affects. You want a nice ordered line of iron atoms, and now there kinda all over the place, not passing the affect down the rod, it just goes out the side or wherever.
The iron rods weren't magnets themselves. They were just supposed to "conduct" or guide the magnetic fields from the neodymium magnets. Once they cooled back below the curie point, they would be able to do that as they'd be attracted to the magnets again. I think the problem was that the magnetic field needs a return path, and without one provided, it would follow the adjacent rods back inadvertently flipping other segments.
I have been collecting non-traditional dice lately and I'm absolutely in love with this. I love how clearly it communicates everything about how it works without sacrificing any other design to do so. I hope my collection includes something like this one day.
This was the first thing I stopped and spent some time grooving over at Open Sauce! Great to get a whole video on it. I would love to see this level of detail on your marvelous kinetic sculpture you had out front.
Ah, I love that feeling when I find a new niche channel to follow. This is delightful, I want to try my hand at a version of this when I have the time for in-person games again. This would be great for a “Box of Doom” style roller for the table!
Just as I had the thought 'oh I bet that sounds great when it spins' you got to the sound test. Just a lovely project overall, great work and great video man!
Just a minor nitpick: chi-squared is usually pronounced by mathematicians with a hard "k" sound (for the greek letter chi), not a "ch" sound. Great video!
More importantly, p = 91% doesn't mean "91% it's fair". It means "91% chance to see at least this much variability with a fair spinner". You can't assign a probability to the likelihood the null hypothesis is correct without a prior belief about it's correctness
100 rolls is a tiny drop in the bucket of a "true" test. but no one ever has time for that :p I do wonder what sort of non-random weight the a) arranging the numbers 0-9 in order caused (since there's a non-random distribution of "change polarity" and "keep polarity" interactions. and b) its been shown that repeated human inducted motion (spin the wheel or Roll the dice) has it's own measurable bias. In all likelihood, those (and whatever other environmental and manufacturing factors) probably don't mess with things enough to care about in real use, but it'd be interesting to see how many decimal places you have to go out before you can see the effect they have.
I love it! I have a thought for how to make it easier to remove inverted magnets: first drill through-holes at all the right index positions, between half to 3/4 of the clearance hole diameter. Then have a drill press with the clearance hole bit & a depth stop. The larger bit should naturally center on the pilot holes well enough; start with a depth too shallow & "sneak up to" the depth where the magnets are flush to the surface. Now if a magnet is backwards, you should be able to knock it out with a punch from the back side pretty easily, especially with a glue that takes 24 hours for "full cure." I'm a mechanical engineer with above-average manual machine shop experience 😉
Excellent! Great to see these original idea build projects, and as I find too, if it has not been done before you make lots of mistakes but persistence gets you there in the end and results in a very pleasing artefact!
I love, love, _love_ these display modules. I kind of wish I could just throw them into every project I do with numeric output that doesn't need to be readable in the dark. Pity they're a bit much for that... I wonder if it's an economy of scale problem?
Instead of bending steel bars to get your magnets into a linear configuration, I recommend trying lengths of coaxial cable, which should be shielded well enough to prevent that crosstalk you ran into. By the way, first-time viewer here - great video!
Coaxial cable will not transmit magnetic flux... Not static flux anyway. Your idea about shielding is correct but coaxial cannot shield against a magnetic field. Coax only shields against induced magnetic fields and that's a dynamic situation only.
packs of thin steel wire, with a wrap of kapton followed by mu metal tape and another layer of kapton, and maybe bismuth or pyrolytic graphite filling the space between them. That ought to work quite well.
I also made dice out of cardstock, back in the 80s. I couldn't find a d30 so I had to experiment with many shapes until I ran across the correct angles for a diamond face. If you use tape on the inside they work well. Use a toothpick ftom the corners to get the last few faces.
Small note, "chi squared" is pronounced like Kai with a hard k, it's the written name of the Greek letter χ which is the symbol used in mathematical notation. Definitely not a huge deal or anything, just a small fyi.
I built a digital dice roller with an ESP32 and a small OLED screen, the hardest part was generating random numbers - surprisingly hard on a microcontroller. I ended up sampling noise from from a breadboard cable just hanging off an input - but I could still feel patterns in the rolls...
Your channel is so enjoyable to watch. The ease you talk about things in such a knowledgeable way is really incredible. I wish you all the followers in the world please keep doing what you’re doing
Thanks for sharing yet another marvelous building endeavor! Should you ever have more time than ideas - let’s recreate and improve Konrad Zuse Z1. That programmable mechanical computer is able to perform float point calculations but is prone to metal stripes stuck and bent irreversibly. The existing replica is close enough to the original to suffer from exactly same problems.
I had no idea these were physical and essentially stable without a supply of electricity. It's sweet. I wonder if a system of small bearing balls and slots with room from 0-10 could be used to retrieve the value from a reservoir, send them to be stored in a line that fits up to maybe 100 balls, then pushed back up to the reservoir with a lever. But then again maybe we don't want to take a little math away from people.
Just a random thought. If you started at 0 every time and used the same amount of force to turn it there's a good chance you will it a similar number. So in turning your testing it even if you don't start every spin on the same number your test will have similar results. A way it could be made more random is to add a clutch type operation for example have a leaver you use the base that will disengage from the magnets, spin so it spins freely then release the clutch so the magnets re-engage and start slowing down. This adds two variables the time from clutch released and the force at twhitch it was pushed. A third variable could be added by the starting number if you wanted to go that deep.
I do lots of CTL stuff at work and have been playing with the affects on dice rolls and game mechanics. Hint: Multiple dice 'opposed' or subtracting some defensive roll from the attacker's, plays the same as multiple dice rolls by turning the result in a normal distribution with a mean of the respective dice difference and a much more limited range than multiple dice rolls for mastery. Manipulate the dice size of each half to set the expected outcome.
two 10 sided dices are way underrated for tabletop rpg's. you can scale most other dice combos to be presented by the 100 easy enough close enough and once in that it's easy to understand the probabilities involved as a novice player and you don't need a bunch of different sorts of dice to play.
It'd take a bigger disc, but you could do a D20 if you compromised in using A-J (with a weird g) for 11-20. Or, a single flip dot for +10 (eg. dot-3 is 13, while no-dot-4 is just 4). You'd still need a big wheel for it though.
Great work! Wish I had stopped by at Open Sauce. If you run into an issue with a super glue-d part again, then you can try using acetone, commonly found in nail polish remover, to dissolve the superglue. It might need time to soak in and go into super tight places, but it's pretty effective! Especially ungluing fingers from each other.
The magnet material is not too very different from lighter flint, chemically speaking: both use an iron-rare-earth intermetallic compound for hardness; the "rare earth" refers to how much the material expands as it oxidizes, and that fluffy oxide breaks itself free of the metal surface as it forms, exposing a fresh surface to oxidize. The boron is the main chemical difference between the two; it burns super hot, yeah. In the case of lighter flint they mostly don't bother purifying the rare earths from one another; it's nominally cerium but has other lanthanides. For NdFeB magnets you need those internal orbitals to be about half full in the final compound, so the distinction matters.
This is outstanding work. I love those old mechanical displays, and I can almost feel the kinetic and tactile satisfaction of spinning that wheel just from watching the video. I told myself a while ago that I can't sub to any more TH-cam channels, but I'm going to have to sub to one more, because I am so very interested to see what you make next.
Really cool. If you were to think of producing it for commercial use, might I suggest exploring 3D printing the disc? Non-ferrous, little extraneous material wasted (notwithstanding the occasional print failure) and a thin cover can be fashioned to hide the magnets to (as another commenter said) make it even more mysterious.
Those cardboard dice were awesome! They reminded me of similar things I resorted to as a kid. (The rest of the build was awesome, too, but I had to comment for the nostalgia hit.)
For the earlier drum style version, I wonder if surrounding the steel rods with copper tubing before bending would help insulate the steel from that magnetic cross-talk.
Now I'm curious of a v2 revision, adding a roller motor. Have a controller apply a random voltage to the motor (carried between minimum motor start voltage up to a safe limit) which would then momentarily run a drive wheel along the edge of the disc, giving it random amount of momentum, then allowing to spin down to stop. Being the momentum would be randomized, as well as the last number the disc was on be essentially an unknown start point, it would be much more random of a roll each time the motor is triggered. Even could have a randomized 0 voltage call, which simply means your result is whatever the current value is. Could additionally randomize it by adding a random timer to the motor run time.
When he started talking about the sound I got the idea to try a split-flap display with some kind of idle or flywheel so that the numbers can continue turning for a little while after the motor stops.
I think another device that would be really cool and use the same type of display could be a microcontrolled version that just pulls a rand out and cycles through numbers till the nth rand, physically switching the display each time. It would be a digital way to recreate that effect, and I think its a cool project idea I might jump into at some point!
Looks great! Just a thought, if you do a multiple dice version, you don’t need every combination shown. You just need to show the total, and have it have the same likely hood of showing up. For example, if you do a 2d6 version, you can have a 7 show up, and weight the week to give it a 1/6 chance of appearing
Absolutely love the project! And I hate to be the insufferable "that guy" but a p-value of 0.91 doesn't mean "a 91% chance its fair." A p-value of 91% means that if we assume the d10 is fair, there's a 91% chance of obtaining a distribution as reasonable as the one you obtained. Therefore you could say "this isn't a crazy distribution to get from a fair d10, so I can't disprove the possibility that it's a fair d10." If you had a p-value of 1% then the correct statement would be "if this was a fair d10 there's a very low chance that I would've observed this crazy distribution, therefore I doubt this is a fair d10."
Really cool! I bet you could get the cylinder version with the straight lines working if you used the rods to transmit force (or position) instead of magnetism. Maybe use some kind of bearing on the rods and impressions on the cylinder surface to set the on/off state of each segment.
This is super satisfying to watch. A percentile version would only need one more row above/beside the current display. 2 independent spinning discs, an inside and an outside disc. I don't know how to make it so you could spin either of them independently of each other, but it could be fun watch8ing you try haha.
Looking forward to the drum system. You could also try some automotive rubber belt to reduce the depth, at the expense of height. Or at the extreme a slab that moves up and down. So many silly options!
Bending rods into a linear array could actually still work, what you need to do is put an antiparamagnetic material in between the rods to increase the barrier separation for the flux. Without doing any serious research and off the top of my head I would recommend pyrolytic carbon sheets between the steel rods. It would increase the amount of potential that the flux would have to traverse in order to tunnel from one rod to the next. It should give you much more granular control over the rods while still having them much closer together. It's basically the magnetic version of electrical insulation
If you could find a display with the ’star’ pattern with the additional sloped pieces, you could use the additional symbols to denote results over ten. Or maybe build a rotor with 20 numerals, ten numbers without a slash and ten without?
You could implement percentile dice the same way geometric dice do: with multiple independent randomisers. Just use more than one spinning disc/drum. You could send the dials spinning at different speeds with the same mechanism as an old-fashioned slot machine.
You'd need some sort of wave guide to redirect the magnetism of the twisted rod or use shielding to prevent crosstalk but the shielding might absorb too much energy. Guiding the magnetic field is trickier than guiding the electric field.
Aluminium is actually magnetic and provides magnetic resistance do to the metal being conductive and making eddy currents inside the metal. Or if a magnet moves close to the metal it makes eddy currents that have a 90° angle to the magnet and that in turn makes a magnetic field that is 180° to the original magnet.
I wonder if you could get better "magnetic insulation" using bismuth or pyrolytic graphite as shielding between the core extensions. You could also try using packs of thin steel wire in place of the solid mild steel rods; this is halfway toward using proper laminations.
6:20 was afraid of this. The heating and bending may alter the metal's crystal structure to the point of unreliably transmitting the magnetic impulse. Second, the adjoining rods are sharing the impulse. Maybe with some kind of electromagnetic shielding between the rods? Once you are back to cylinders, which need multiple diameters, you might end up needing rods again to transmit the impulse to a level 'display field' at the outer radius, depending on your physical design. Linked multiple digits (all on one cylinder) are going to run against interval limit and how many detents you can set, so each display/digit probably winds up as it's own cylinder on a shared axle. D100 could be reduced to spinning two d10 adjacent or sequentially. (d10x2 or d10+"d10s", with 0 fixed after the rolled tens digit). 9:55 so many metals happily eating oxygen at literal grams/second
Great video, thank you. I am not totally sure but I think that the display rubbing on a precise sequence of magnets will have some kind of statistical skewing of the results, I would think it’d be better if it would only touch the resulting magnets after it finished spinning, clearly that would be much more difficult to implement and since I am not sure I am right you probably shouldn’t. Thanks for the video!
The sound truly is delightful. I want that to be THE sound effect for "some sort of RNG is happening".
It does sound like rrrrrnnnnnnnnnng-g-g--g-----g------g :D
I like that it shows non-numbers between valid outputs. That’s a feature, not a bug.
The final build looks like something out of a Cyan Worlds game that would be a little in universe flavor to learn the numbers of a fictional written language.
Good timing too, the Riven remake is out today
@@HubrisIncbased vr mode
I really want to try those games
Just as you said "Happy RNG day" I thought to myself "I hope the date is different every year" and you didn't disappoint.
Actually, if you cover the disk with thin aluminum sheet, so individual magnets are no longer visible, it will be even more satisfying and "mysterious".
The aluminum may act like a brake though. While it isn’t ferrous it is metal and responds to moving magnetic fields.
@@NandRIt wouldn't be a breaking effect though, as no eddy currents would be generated as the magnets would be spinning with the aluminum.
@@electrifyingvids3545 There are magnets on the display though...
@@joey_f4ke238 Perhaps they could switch to silver plated plastic? The silver would provide negligible eddy currents.
We tried that, and a small portal opened up, so we shut it down, like CERN in 2027, fyi, the future sucks!
This video really reminds me of a classic 2010 TH-cam video. And I mean that as a most sincere compliment! Thank you for showing up in my feed!
Same here. I love it's not overly produced.
@@ddegn Indeed, but it's structured enough to keep you engaged!
I'm glad I randomly landed on this video, particularly on this day.
I randomly missed a day
Since you just want random numbers and don't care about them being arranged sequentially in the spinner, you can overlap the positions and reuse magnets from the previous position for the next one. EG 2,3,5,6 and 8 all have three horizontal segments so you can get away with just one set of magnets to flip them on for half the wheel and then another set to flip them (as needed) in the other half of the wheel. You can also take advantage of the fact that the top half of the vertical segments are the same in 2/3 and in 5/6 whereas the bottoms are the same for 3/5 and 6/8. Meaning you just need to encode which bits to flip, not the whole state of the display per position. And, by just encoding the flips not the full data, you can cut down drastically on the space needed in the wheel.
I like this line of thinking, but I can't help but think that there would be some inevitable failure in the magnets flipping every node every time, at least when the disc is spinning fast. The one nice thing about parking the display over a full array for every number is that every node lands on a magnet that ensures it reads correctly. And having the same number of magnets on every number also helps balance the weight and spinning speed to reduce bias. I would think since magnets determine where the wheel stops, having more or fewer on different numbers could make them more or less likely to appear. I could be completely wrong though.
@@shotguntornado if you have a reset field (all on/all of) maybe it could be enough. Because in the end you only care about the correct flips once it slows down. And you should already have the bias in the wheel as it is. The one that has only "repellors" should be more unlikely than one that has only attractors or do the displays not work like that?
Won't that mean it only works in one direction, though? Since a magnet doesn't "flip" a bit, it's specifically writing a 0 or 1. If you set it so going from 6 to 8 just entails activating the top-right pair, then going from 8 to 6 will only keep them on.
Neat idea but the end result would just be the display showing an 8 since the magnets would pass over and flip things which weren't supposed to flip.
@@SollowP I didn't even consider that, yeah you can't just choose to flip a left or right side. You can't flip a 3 into a 5 without it becoming a 9 for example.
9:39 you just released the little magnetism demon trapped in the magnet
So that's how magnets work!
i love dice and dice adjacent peripherals but my favorite part was drilling into that magnet. would not have thought it would look like that
I wonder if there was a termite reaction going on? Iron and aluminium burning?
@@m1geo Probably just straight up burning. It's a cermet, there isn't any aluminum metal in the magnets. That wouldn't work since they're sintered! It's just straight up burning, for a thermite reaction you need an oxidized metal and a metal that wants to pull the oxygen. Rust (iron oxide) + aluminum = pure iron + aluminum oxide + heat. There is no oxidized metal in a neo magnet, so it can't be a thermite reaction. That means it's just straight up metal fire :) I mean there is a tiny amount of aluminum used probably as a flow modulator and plasticity enhancer during the pressing, that just kinda does nothing after sintering, but you aren't getting a thermite reaction with .2% aluminum. It's just normal combustion oxidizing all the metals
@@dogsarebest7107 "Probably just straight up burning."
Well, it's glowing. The drill bit would melt long before reaching the temperatures required to ignite the metals in the magnet.
@@vinny142 No, definitely not. That's a tungsten carbide endmill. They happily turn steel into burning shards, happily turn titanium into raging fires, what makes you think it won't do it for this?
It has to do with PHYSICS. Small particle size means LOW THERMAL MASS and HIGH SURFACE AREA. That means it burns REAL EASY. Why do you think microscopic powder generated is HARDER to ignite, than a solid chunk of tungsten that weighs several ounces? Even ignoring the fact that one particle igniting, generates heat that then raises the temperature of adjacent particles to either very near, or above the autoignition temperature. That's how exothermic reactions are defined. Have you seen any machining videos? Never seen a spark happen? Never see ribbons of metal burn? Touch a 9v battery to steel wool and think about it
Static electricity can happily ignite aluminum powder or titanium powder, but the spark doesn't vaporize your finger. Because.. physics.
Thank you for the quality closed captions. They are greatly appreciated.
Even watching this thing spin is satisfying, can't imagine how extremely delightful it is to spin it in real life.
This is an incredible project. I have a deep affection for those mechanical flip displays, machined metal, and random number generation. Really a perfect storm for me. Thank you for your fantastic content
this got me thinking about how cool it would be to have a revolver where the cylinder has the magnets around the outer circumference, and have the display mounted on the top.
would be fun to play a western style game, pull out your revolver, give it a spin and have the 'roll' shown to you. add a little flair to your roleplay. especially so if your rolling D6s for damage since many revolvers are 6 bullet capacity so it would really be fitting
Fascinating idea and of course the numbers arranged appropriately will count down remaining ammo
I have a revolver cylinder with a full set of bullet dice just for this purpose
Now I'm imagining 3d printing a toy revolver in your design for use in a Russian roulette "game".
You’ve hit it out of the park with your explanation, no, story telling about statistics. It’s honestly a delight to watch.
I love projects like this. They start with just a question or curiosity and then morph and materialize out of thin air. No one asked for this specific thing. Not even you. And yet, now it exists, and it's AWESOME. Love it.
Nice build! Regarding the cylinder + magnet channels idea, at 04:25 you could tilt the display about 18° clockwise (or 12° CCW) to have the Y positions of each magnet be somewhat equally spaced, and it might be possible to design a cylinder where the 7 magnets for a given digit are not in a straight line, but in a weird pattern that matches the exact position of the display. It's a bit difficult to explain but I can sketch something if you'd like :) smaller magnets in the cylinder would probably be required (and a ton of magnets if you want a d100)
This was a ton of fun to play with at OpenSauce. I will not admit how much time I spent spinning the dial or just admiring the simplicity.
You solved two problems (percentile is just two of these). You only need a single bit display to extend it to a d20, as many early d20s did double duty before the modern d10 shape took hold. They would have 0-9, and 0-9 again but with a dot. If you were using it as a d20, the dot was worth 10. If you were using it as a d10, you ignored the dot. In your case, perhaps use a second digit that either underlines the number, or doesn't. Then the viewing window could hide most of the extra display and you're only adding one magnet per number (although twice as many numbers).
If you build a d20 disc this way, it can double as one digit of your percentile die so you wouldn't need a second d10. You could also use it in conjunction with the d10 to speed up that Eldritch Blasting.
Similarly, you could make a dual-purpose d12/d6 spinner, and a dual purpose d8/d4 spinner.
to be fair I started at lapidary, cutting open geodes and agate, a wee touch on jewellery making and then the algorithm decided it was dice so I had people carving dice on diamond wheels casting them, all sorts. even just some showing off dice. now the algorithm has brought me back to machining just with more dice. cool video dude.
Oh how I wish i could find one of those 7-segment displays for myself. 2 weeks searching and no luck. I would love to have made one myself out of some laser cut wood for my D&D kids. I absolutely love this and would love to see how you would tackle a D20.
The Kessler Syndrome being perhaps not as unfun as you'd hoped is a pretty great turn of phrase. xD
Where are more details of the game? I checked Mastedon and only saw a few screenshots.
@@bernardandrys2397 Would be cool to see gameplay of this and even better if it were released on Steam.
Great video! If you want to ream a hole oversized with a nominal reamer, you can shove a greased-up paper towel wad into the hole. You'll manage to oversize it by about 1.5 thou. If you need a little less slip, if you run it at a higher RPM and feed more slowly, you can shave off a bit less. As with drill bits, you'd be surprised how a reamer can be manipulated!
That spinner is awesome. It looks like something from a star trek casino!
the thing I like about your channel is that you just do what you think is intresting and fun without worrying that it may not perform the best on youtube or other stuff like that
I won't shed any tears about a non-platonic solid, so well done! Beautiful project!
Ack I'm sorry I missed your booth at Open Sauce. Hope you had a great time. I think this project is very understated in terms of all the cool design decisions involved in creating the spinner. Keep making cool stuff!!
You can still do press fit magnets in a drilled hole, but you can't use pressure. It's counterintuitive but if you chill the metal the hole will get larger not smaller. If you chill the metal sufficiently it's effectively and largening the whole big enough to accept the magnet without any serious force and then the magnet gets clamped when the metal warms back up to room temperature. Chilling also doesn't damage the magnets that way. You might be able to use dry ice to chill it, but I'm more effective mix might be liquid propane.
I would love to see a miniaturized version of this, maybe of a handheld size. Of course, that would mean that an even smaller flip digit display would need to be made as well.
Really cool project. Your last video about the map/clock and this one were such pleasure to watch.
I like that you don't hesitate to get in to the details without getting stuck to any particular step for too long.
Subscribed!
I think when you heated the metal with a gas torch you took it past the curie point which messed with its magnetic affects. You want a nice ordered line of iron atoms, and now there kinda all over the place, not passing the affect down the rod, it just goes out the side or wherever.
is there a way to restore it? like, magnetising the metal while it's red-hot and cooling?
The iron rods weren't magnets themselves. They were just supposed to "conduct" or guide the magnetic fields from the neodymium magnets. Once they cooled back below the curie point, they would be able to do that as they'd be attracted to the magnets again. I think the problem was that the magnetic field needs a return path, and without one provided, it would follow the adjacent rods back inadvertently flipping other segments.
The way your story parallels what became of music, from tubes to flat sheets, quite interesting. Nice design, GG!
I have been collecting non-traditional dice lately and I'm absolutely in love with this. I love how clearly it communicates everything about how it works without sacrificing any other design to do so.
I hope my collection includes something like this one day.
Did you mess with the color correction of the area under your eyes? It looks greenish.
Looks and feels like something between d10 and roulette. You know "roll on black to open this door"🌝
This was the first thing I stopped and spent some time grooving over at Open Sauce! Great to get a whole video on it. I would love to see this level of detail on your marvelous kinetic sculpture you had out front.
I have a bunch of tiny neodymium magnets from an abandoned project. I wonder if I can make my own flipdot modules. To the workbench!
Ah, I love that feeling when I find a new niche channel to follow. This is delightful, I want to try my hand at a version of this when I have the time for in-person games again. This would be great for a “Box of Doom” style roller for the table!
Just as I had the thought 'oh I bet that sounds great when it spins' you got to the sound test. Just a lovely project overall, great work and great video man!
I love the sound of it SO. MUCH.
Glad I found you through your Geochron video!
First video of yours I've had the pleasure to see.
Concise, fun, and entertaining.
Very nice work.
Randomly recommended 4 days later.
Cheers indeed.
Just a minor nitpick: chi-squared is usually pronounced by mathematicians with a hard "k" sound (for the greek letter chi), not a "ch" sound. Great video!
More importantly, p = 91% doesn't mean "91% it's fair". It means "91% chance to see at least this much variability with a fair spinner". You can't assign a probability to the likelihood the null hypothesis is correct without a prior belief about it's correctness
latek?
Here from Hackaday, awesome project! As a designer/fabricator/Dimension 20 fan/DM, this project tickles me on so many levels!
100 rolls is a tiny drop in the bucket of a "true" test. but no one ever has time for that :p I do wonder what sort of non-random weight the a) arranging the numbers 0-9 in order caused (since there's a non-random distribution of "change polarity" and "keep polarity" interactions. and b) its been shown that repeated human inducted motion (spin the wheel or Roll the dice) has it's own measurable bias. In all likelihood, those (and whatever other environmental and manufacturing factors) probably don't mess with things enough to care about in real use, but it'd be interesting to see how many decimal places you have to go out before you can see the effect they have.
I love it! I have a thought for how to make it easier to remove inverted magnets:
first drill through-holes at all the right index positions, between half to 3/4 of the clearance hole diameter. Then have a drill press with the clearance hole bit & a depth stop. The larger bit should naturally center on the pilot holes well enough; start with a depth too shallow & "sneak up to" the depth where the magnets are flush to the surface.
Now if a magnet is backwards, you should be able to knock it out with a punch from the back side pretty easily, especially with a glue that takes 24 hours for "full cure."
I'm a mechanical engineer with above-average manual machine shop experience 😉
Excellent! Great to see these original idea build projects, and as I find too, if it has not been done before you make lots of mistakes but persistence gets you there in the end and results in a very pleasing artefact!
I love, love, _love_ these display modules. I kind of wish I could just throw them into every project I do with numeric output that doesn't need to be readable in the dark. Pity they're a bit much for that... I wonder if it's an economy of scale problem?
I saw your booth at Open Sauce! really cool stuff you have. I didn't know how much time and effort went into such a seemingly simple device.
Instead of bending steel bars to get your magnets into a linear configuration, I recommend trying lengths of coaxial cable, which should be shielded well enough to prevent that crosstalk you ran into. By the way, first-time viewer here - great video!
Coaxial cable will not transmit magnetic flux... Not static flux anyway. Your idea about shielding is correct but coaxial cannot shield against a magnetic field. Coax only shields against induced magnetic fields and that's a dynamic situation only.
For magnetis screening..Mu metal is your thing ( mu pronounced moo )
@@jasonudall8614 that's exactly what I was going to comment
packs of thin steel wire, with a wrap of kapton followed by mu metal tape and another layer of kapton, and maybe bismuth or pyrolytic graphite filling the space between them. That ought to work quite well.
I also made dice out of cardstock, back in the 80s. I couldn't find a d30 so I had to experiment with many shapes until I ran across the correct angles for a diamond face.
If you use tape on the inside they work well. Use a toothpick ftom the corners to get the last few faces.
You easily earned a subscription with this one. Great walkthrough of a really clever build!
I've had success using a spring center punch to shatter magnets in the holes then a pick to get them out. Also CA glue uncuring agent helps
Small note, "chi squared" is pronounced like Kai with a hard k, it's the written name of the Greek letter χ which is the symbol used in mathematical notation. Definitely not a huge deal or anything, just a small fyi.
You are very cool. I just wanted to give that affirmation, love your project!! :)
I built a digital dice roller with an ESP32 and a small OLED screen, the hardest part was generating random numbers - surprisingly hard on a microcontroller. I ended up sampling noise from from a breadboard cable just hanging off an input - but I could still feel patterns in the rolls...
Your channel is so enjoyable to watch. The ease you talk about things in such a knowledgeable way is really incredible. I wish you all the followers in the world please keep doing what you’re doing
Thanks for sharing yet another marvelous building endeavor!
Should you ever have more time than ideas - let’s recreate and improve Konrad Zuse Z1. That programmable mechanical computer is able to perform float point calculations but is prone to metal stripes stuck and bent irreversibly. The existing replica is close enough to the original to suffer from exactly same problems.
I had no idea these were physical and essentially stable without a supply of electricity.
It's sweet.
I wonder if a system of small bearing balls and slots with room from 0-10 could be used to retrieve the value from a reservoir, send them to be stored in a line that fits up to maybe 100 balls, then pushed back up to the reservoir with a lever. But then again maybe we don't want to take a little math away from people.
Your videos are very enjoyable. I love your curious, hands on character. You share your thought process well!
I saw you at open sauce 2024, saw this project and soo happy to a found your youtube channel ! keep it up man
What a wonderful project! That sound is sooooooooooo satisfying!
Just a random thought.
If you started at 0 every time and used the same amount of force to turn it there's a good chance you will it a similar number.
So in turning your testing it even if you don't start every spin on the same number your test will have similar results.
A way it could be made more random is to add a clutch type operation for example have a leaver you use the base that will disengage from the magnets, spin so it spins freely then release the clutch so the magnets re-engage and start slowing down.
This adds two variables the time from clutch released and the force at twhitch it was pushed. A third variable could be added by the starting number if you wanted to go that deep.
It was lovely to meet y'all at Open Sauce, and get to try the spinner in-person. It's lovely.
I do lots of CTL stuff at work and have been playing with the affects on dice rolls and game mechanics. Hint: Multiple dice 'opposed' or subtracting some defensive roll from the attacker's, plays the same as multiple dice rolls by turning the result in a normal distribution with a mean of the respective dice difference and a much more limited range than multiple dice rolls for mastery. Manipulate the dice size of each half to set the expected outcome.
two 10 sided dices are way underrated for tabletop rpg's. you can scale most other dice combos to be presented by the 100 easy enough close enough and once in that it's easy to understand the probabilities involved as a novice player and you don't need a bunch of different sorts of dice to play.
Damn i love this project! Subscribed, really need to know more about that cabinet. Keep going! Thanks for sharing
It'd take a bigger disc, but you could do a D20 if you compromised in using A-J (with a weird g) for 11-20. Or, a single flip dot for +10 (eg. dot-3 is 13, while no-dot-4 is just 4). You'd still need a big wheel for it though.
Great work! Wish I had stopped by at Open Sauce. If you run into an issue with a super glue-d part again, then you can try using acetone, commonly found in nail polish remover, to dissolve the superglue. It might need time to soak in and go into super tight places, but it's pretty effective! Especially ungluing fingers from each other.
I would squeal for a mechanical clock with this display mechanism.
The magnet material is not too very different from lighter flint, chemically speaking: both use an iron-rare-earth intermetallic compound for hardness; the "rare earth" refers to how much the material expands as it oxidizes, and that fluffy oxide breaks itself free of the metal surface as it forms, exposing a fresh surface to oxidize. The boron is the main chemical difference between the two; it burns super hot, yeah. In the case of lighter flint they mostly don't bother purifying the rare earths from one another; it's nominally cerium but has other lanthanides. For NdFeB magnets you need those internal orbitals to be about half full in the final compound, so the distinction matters.
This is outstanding work. I love those old mechanical displays, and I can almost feel the kinetic and tactile satisfaction of spinning that wheel just from watching the video. I told myself a while ago that I can't sub to any more TH-cam channels, but I'm going to have to sub to one more, because I am so very interested to see what you make next.
Kudos maker, solving problems no one else thought of.
I am in awe!
Really cool. If you were to think of producing it for commercial use, might I suggest exploring 3D printing the disc? Non-ferrous, little extraneous material wasted (notwithstanding the occasional print failure) and a thin cover can be fashioned to hide the magnets to (as another commenter said) make it even more mysterious.
That thing sounds like a shaman staff. . . Why do I want one?. Great build. Great idea.
Those cardboard dice were awesome! They reminded me of similar things I resorted to as a kid. (The rest of the build was awesome, too, but I had to comment for the nostalgia hit.)
For the earlier drum style version, I wonder if surrounding the steel rods with copper tubing before bending would help insulate the steel from that magnetic cross-talk.
😍 That sound when it spins... Awesome build ! :D
Now I'm curious of a v2 revision, adding a roller motor. Have a controller apply a random voltage to the motor (carried between minimum motor start voltage up to a safe limit) which would then momentarily run a drive wheel along the edge of the disc, giving it random amount of momentum, then allowing to spin down to stop. Being the momentum would be randomized, as well as the last number the disc was on be essentially an unknown start point, it would be much more random of a roll each time the motor is triggered. Even could have a randomized 0 voltage call, which simply means your result is whatever the current value is. Could additionally randomize it by adding a random timer to the motor run time.
When he started talking about the sound I got the idea to try a split-flap display with some kind of idle or flywheel so that the numbers can continue turning for a little while after the motor stops.
I think another device that would be really cool and use the same type of display could be a microcontrolled version that just pulls a rand out and cycles through numbers till the nth rand, physically switching the display each time. It would be a digital way to recreate that effect, and I think its a cool project idea I might jump into at some point!
Looks great! Just a thought, if you do a multiple dice version, you don’t need every combination shown. You just need to show the total, and have it have the same likely hood of showing up.
For example, if you do a 2d6 version, you can have a 7 show up, and weight the week to give it a 1/6 chance of appearing
Absolutely love the project! And I hate to be the insufferable "that guy" but a p-value of 0.91 doesn't mean "a 91% chance its fair."
A p-value of 91% means that if we assume the d10 is fair, there's a 91% chance of obtaining a distribution as reasonable as the one you obtained. Therefore you could say "this isn't a crazy distribution to get from a fair d10, so I can't disprove the possibility that it's a fair d10."
If you had a p-value of 1% then the correct statement would be "if this was a fair d10 there's a very low chance that I would've observed this crazy distribution, therefore I doubt this is a fair d10."
Severely underrated comment smh
Really cool! I bet you could get the cylinder version with the straight lines working if you used the rods to transmit force (or position) instead of magnetism. Maybe use some kind of bearing on the rods and impressions on the cylinder surface to set the on/off state of each segment.
This is super satisfying to watch. A percentile version would only need one more row above/beside the current display. 2 independent spinning discs, an inside and an outside disc. I don't know how to make it so you could spin either of them independently of each other, but it could be fun watch8ing you try haha.
Looking forward to the drum system. You could also try some automotive rubber belt to reduce the depth, at the expense of height. Or at the extreme a slab that moves up and down. So many silly options!
Glad to a see a creator like yourself get noticed! It takes a long time to become an overnight success. This spinner is wicked cool!
Bending rods into a linear array could actually still work, what you need to do is put an antiparamagnetic material in between the rods to increase the barrier separation for the flux. Without doing any serious research and off the top of my head I would recommend pyrolytic carbon sheets between the steel rods. It would increase the amount of potential that the flux would have to traverse in order to tunnel from one rod to the next. It should give you much more granular control over the rods while still having them much closer together. It's basically the magnetic version of electrical insulation
This video has really nice pacing, good cinematography, and quality editing. I like the dual narrator to break up sections.
If you could find a display with the ’star’ pattern with the additional sloped pieces, you could use the additional symbols to denote results over ten. Or maybe build a rotor with 20 numerals, ten numbers without a slash and ten without?
If random values is the end goal, the sequence of the numbers on the disc should also be randomized.
You could implement percentile dice the same way geometric dice do: with multiple independent randomisers. Just use more than one spinning disc/drum. You could send the dials spinning at different speeds with the same mechanism as an old-fashioned slot machine.
You'd need some sort of wave guide to redirect the magnetism of the twisted rod or use shielding to prevent crosstalk but the shielding might absorb too much energy. Guiding the magnetic field is trickier than guiding the electric field.
Aluminium is actually magnetic and provides magnetic resistance do to the metal being conductive and making eddy currents inside the metal. Or if a magnet moves close to the metal it makes eddy currents that have a 90° angle to the magnet and that in turn makes a magnetic field that is 180° to the original magnet.
I wonder if you could get better "magnetic insulation" using bismuth or pyrolytic graphite as shielding between the core extensions. You could also try using packs of thin steel wire in place of the solid mild steel rods; this is halfway toward using proper laminations.
Was really cool to see this at Open Sauce. Very satisfying to spin.
Coherent channel themes, who needs them
Regular and coherent are so boring, I’m here for that drip-feed of neat passion projects to distract me from my pile of incomplete passion projects 😂
6:20 was afraid of this. The heating and bending may alter the metal's crystal structure to the point of unreliably transmitting the magnetic impulse. Second, the adjoining rods are sharing the impulse. Maybe with some kind of electromagnetic shielding between the rods?
Once you are back to cylinders, which need multiple diameters, you might end up needing rods again to transmit the impulse to a level 'display field' at the outer radius, depending on your physical design. Linked multiple digits (all on one cylinder) are going to run against interval limit and how many detents you can set, so each display/digit probably winds up as it's own cylinder on a shared axle. D100 could be reduced to spinning two d10 adjacent or sequentially. (d10x2 or d10+"d10s", with 0 fixed after the rolled tens digit).
9:55 so many metals happily eating oxygen at literal grams/second
I think this spinner would be very fitting for a gunslinger character because it kinda seems like a revolver barrel
Great video, thank you. I am not totally sure but I think that the display rubbing on a precise sequence of magnets will have some kind of statistical skewing of the results, I would think it’d be better if it would only touch the resulting magnets after it finished spinning, clearly that would be much more difficult to implement and since I am not sure I am right you probably shouldn’t. Thanks for the video!