Hemispheric Flapping Display
ฝัง
- เผยแพร่เมื่อ 23 เม.ย. 2021
- My attempt at building a larger Hemispheric FlexLED (Version 3)
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attach the semicircle to the main arm - the end flapping is acting as a dampener making it so you can't get higher frequencies
Or remove the main arm and use both sides of the semicircle to drive the semicircle.
Well having the center not attached would create a similar, though much less significant issue, I think ideally you have a mesh that connects the whole array to the pivot point, which is only flexible in one direction
The long exposure image looks like a scifi mapping of the human brain!
It does 😂
@@CarlBugeja It's really cool
This is so freaking cool. I think you should use a thin layer of foam or some soft material to stop hard hitting of LEDs on 3D printed parts which may increase their working life.😀
Good idea! My idea behind the proximity touch pads is to prevent them from hitting the plastic but that could be used as an extra precaution
@@CarlBugeja Will wait for that upgrade too. 🤞
Also maybe have 2 or 3 parallel flippers with a single led arc on top like the one you use - it seems like it is wide enough.. 🤓🤔
@@CarlBugeja why dont you counterweight the leds so its not so heavy? and also add a magnet above it for double the strength
Try and match the voice volume to the music. have to adjust the volume constantly to hear you and not wake the neighbours
@Dfirebug no, just make the music quieter. I don’t need to hear the music at all honestly
this is automatically achieved by making voice louder and then applying compressor
That long exposure shot was sick!
I feel like you need to experiment with the spring stiffness, maybe by doubling or tripling up on the stem flex board part
exactly- 2 or 3 stems would stabilize the motion and additional spring restoring force would allow a higher max frequency
“Evil Villain Machine” is a great phrase. Every sketchy looking device you make should be labeled that!
😂😂
Evil villain machine "Name"-Inator of course
"The Force is strong with this one"... I could see how satisfying it was to say that hah! Keep it up man, loving the channel
The natural frequency only depend on the mass and stiffness.
If you want it to go faster, you will need a stiffer flex cable. You should also make it longer so the extremities of the arc dont go in reverse direction.
I think you could also put the magnets along the path of the coil instead of at each ends. You then might need some tortional stiffness too tho.
Thank you for this comment, I was close to screaming it at the screen 😅. He never altered the 'crux' of the problem, the recoil speed of the flex cable! Well spotted, peace from Ireland to you and yours x
You could use a rigid pcb and spin it with a motor. You can use a wireless charger for power and some LEDs and photo diodes for data.
Really well done. I appreciate you showing all the hard work that you've put in to this. Fail, fail, fail but get back up again! Can't wait to see version 4!
I think redesigning the PCB from a 'T' shape to a '∩' shape might help. Then there would be 2 drivers at both sides of the upside-down 'U' increasing the actuation force and frequency. It would also increase the size of the display (allow for more LED's) because now you don't have to worry about the ends of the T flopping anymore.
Cool experiment with the new geometry! Excited for version 4!
So much hard work. Congratulations. Seeing all this I would have change to a rotating led cylinder or barrel for much higher frequency.
Dude, you're awesome for continuing to develop this line of work. And also, of course, you're a great engineer and a great guy in general!
Maybe separate the main ribbon into two , with some space between them (like a П shape)? It will stabilise it on flipping axis , just guessing though:)
Great work, really love it ! I think if you change the design of FlexLED it will solve most of your problems. It surely needs more flexible stems so that it won't wobble as much, while keeping the same semi-circular shape.
I have some suggestions. Instead of one central connector, you could have one at each extremity to avoid torsion. You could increase the stiffness of the material or increase the total width of your connector. This will increase the speed of the natural resonance frequency of your system. If you drive your electric signal at the natural resonance frequency it will move easily. If you put more than two connectors, you cannot have an arc of a circle of LEDs because the length of each connector won’t be the same so the natural frequency.
❤❤❤😮😅😅 pm❤❤❤❤❤❤❤❤❤❤
Your steel plates under the magnets should be continuous between the two magnet poles - in effect, completing the magnetic circuit and turning the two magnets into one (like a horseshoe magnet). That will reduce the flux density on the underside and increase it in the gap between the top poles.
The same 'trick' works on motors where the magnets are stuck to a ferrous ring to increase the flux density on the exposed faces.
It is always satisfying for me seeing Ur videos because there is some progress ,some day I'll also feel that satisfaction for completing my projects😂👍👍
Great work bro
It might help to have two _stems_ instad of just one. It won't be as flimsy maybe.
4:20 I think because the „arms“ of the new flexpcb can flex as well they act as counter, stealing kinetic energy from the system.
You have a new sub in me my man. This is next level project building. Thank you for filming it!
Hey! You should increase the spring effect in the "arm". It will help the led to go back up.
Increasing the spring effect means that you will require a bigger force to bend it tight. But the coil has a greater effect when it get close to the magnet. So I think tye spring producing a hisgh force in tight bend will be countered by the coil having more action near the magnets.
Thus the spring can really help you pass the high point in the middle where you don't have much action for now
Awesome project! I love these quirky builds of yours. If I may say from the mechanical side of things, I'd recommend not having the led in a halo shape like that, perhaps a semi circle might work better. With more mass further from your pivot point you have more angular momentum and a harder time changing direction. Also a lot of energy is wasted in the 'flapping' of the halo, if you can make that part more rigid I think would be more reliable. Maybe pinning the ends about the axis of rotation could help? Add a small loop to the ends of the 'halo' and put a rod through them.
i really enjoyed this video, i loved the editing, the pacing, and the project itself! great video Liked, and subscribed
I think you could “hinge” the ends of the leds maybe also adding some springs so the magnets dont have to work so hard the first few degrees
Adding supports to the main core - so it will look like a parachute, in theory should hold the contraption in the middle, then you only need to balance the magnets. Good luck! hope it works :D
I think the performance issues might have something to do with the long flexible "arms" or ribbons of LEDs. They probably work kind of like shock absorbers when you try to reverse the direction of the movement.
Also, the larger magnets may induce large enough currents in the coil to disturb the movement even further. This is just a wild guess though.
Make two coil(one left and one on right) for reducing wobbling and improve force. Also if you get some sort of feedback signal, you can shift phases for dynamic compensation of wobbling.
Man keep up the good work i can't wait what improvement you might do next
You could try to add a small steel torsion spring (actual torsion spring or simple steel bar) at the base of the flexing stem, and drive it at its resonant frequency. The frequency is defined by the stiffness of the spring and the inertia (mass) of the moving part. This has many advantages:
1- You would need very little energy to sustain a vibration (only compensate for the air resistance and heat dissipation of the deforming material)
2- You could get away with much smaller magnets (don't need large forces if they're only sustaining the natural resonance of the system)
3- You could attain arbitrarily high frequencies (by increasing the stiffness of the spring)
4- You could tune it so the pcb doesn't strike the magnets (less wear)
At some point, you'd also have to consider tuning the resonant frequency of the arms of the led arc. iirc, if the resonant frequency of the arms is higher (stiffer / ligher) than the stem, they will simply follow the stem at it's lower frequency. If their frequency if lower, they might interfere with the motion of the stem.
Hope this helped.
great video, cant wait to see whats next.
We can't wait to see what youuuuu dooooo neeeeeeeeext...
More power to you brother. Very good work and progress 👍👍
Hi, I love your videos and flex-display development! This may seem counter intuitive, but I believe you need a stiffer flex pcb arm. I am talking about the part of the flex pcb that flexes and holds the coil ant leds on its end. The increased stiffness will help the assembly flex back faster after a travel to one side.
I think that will be cool if you try a similar ideia with a floating bar between magnets energized by its sides, showing some different shapes. The data could be transferred to the circuit on the bar by a Bluetooth chip!
I love this project, I hope you keep working on it because It'll be really cool if it works as intended,.
This guy doesn't lose the hope 👍🔥
the arm needs to be stiffer and wider, with "spokes" connecting the semicircle to the fulcrum in a fan shape to reduce some of the wiggling without adding too much air resistance. A new housing with "tracks" on either side to stabilize and guide the semicircle in a straight arc would also help a lot. to reduce damage to the LEDs (and dampen the ticking noise it makes), add a thin layer of silicone over the magnet housing, or just simple foam stickers.
Nice work, and good status report
You should seal the display in a vacuum chamber. CRT monitors also used it. Fixing the sides of the display to the ground would improve stability.
I think the issue is more with the length of the cable trying to flex and all the added surface area and mass on the top. Its likely the strong forces caused by movement at the top and the ends are likely keeping your speed so low, it has to drag everything along with it and it can't just accelerate so quickly.
Edit - A reciprocating motor connected to a 3d printed arm and supports glued to the strip would let you achieve a faster refresh rate.
Humankind is going to need that technology for space.
Just because it's so light and can bend within and around 'tubular structures' ;-)
I think you can model this with bending spring and mass as a rough harmonic oscillator. You can probably estimate the spring force from the bending equations: en.wikipedia.org/wiki/Bending
Carl, try adding more plastic spokes to force the actuator flip with a fixed angle. These spokes segments should not have any electronic components, they will just help mechanically.
Next rendition of the flex LED arc, make the LED contacts in a different orientation.
Here's an idea. 4 FlexARs arranged to each actuate 90 degrees of a circle. See if you can redraw the coil to simulate a halbach array.
If you arrange them like an 'X' then you can get the FlexARs to jump together at the top and bottom, then actuate in the reverse direction and touch at the left and right sides. If that doesn't work, you could try 6 or 8 actuators. Also, why not try electroluminescent wire instead of LEDs?
Try to add axis and to move coil to the side opposite to leds, you should be able to place magnets at sharper angle, and use the flexibility and inertia. Sorry for my English.
Have you considered a more traditional rigid PCB on a hinge? Constraining the motion around one axis might help make the force on the coil by the magnets more consistent (but might not be as fun :). Love the videos!
Consider anchoring the ends of the LED strip to prevent the outer LEDs from wiggling around so much. The added stability might help reliability as well as display fidelity.
I wonder if air resistance may be significantly affecting (dampening) the movement..keep up the good work!!
You could try a spring, either a thin piece of spring steel or an actual spring along the flex. However to get this to work you would need to manually start the system. I also think with this method you could avoid the LEDs hitting the magnets. Different strength springs would give a different harmonic frequency, so you could tune it to the exact refresh rate you want. You might need a feedback circuit to drive it as it enters to field for the first start, and maybe to keep it resonating.
My personal preference would be a standard coil spring, with the flex running inside of it, retained by a 3d printed collet in the base, and at the top of the flex. Might have difficulty getting flex up the inside of the spring, but this could let you preload it a little as well.
consider additional flex points, for stability and to keep it from flexing side to side more... it would also introduce some rigidity to allow for bigger LEDs
@Carl Bugeja This is super cool. Is there a use case where hemispherical POV display is preferable to something like a simple spinning circular POV display?
Ohh... A alternating display 😁
It's going great 💯
New channel logo, nice
Man goes "Wow, this is great. Let's put some dampeners on it and watch it go faster!"
"Wait why is it going slower with the dampeners"
Have you considered or tried using a spring so that the neutral position of the array is sticking straight up?
Alternatively, you could mirror the whole design to make a sphere instead of a hemisphere. The shaft could be non-flexible with a pivot in the middle so that the whole thing is counterbalanced.
That way the neutral position would be vertical and when the top half is being pulled toward the right magnet, the bottom half could be pulled toward the left magnet and vice-versa.
In fact, the whole thing (except maybe the coils) could be non-flexible pcb, which might help with the warping.
This is working okay but got me thinking... two suspended wires running parallel with each other, with opposite charges tend to bow or curve based on electromagnetic attraction/repulsion. Why not set up a suspended grid of wires and use the flexAR circuit drive pairs of wires? The oscillating frequency should cause a similar wiggle effect. Micro led strings could then be fixed to the wired grid. The grid vibrate in the timing you want and cause the lights to do the same. You may need a bit more current to run everything being as you'll need power to drive the wire grid, and power to run your led matrix. This should allow for a cubic volumetric display that has a refresh rate for the led firing, and the grid vibration attenuation.
I find your work inspiring. Keep it up Carl. ❤👍💪
I suspect if you link the edges to the middle, and widen/bifurcate the vertical support you'd get better results!
very cool R&D :) The sides seam to wiggle and waste kinetic energy. Maybe you could reduce the thickness of the connection in the middle and move some to the outside to constrain it a bit better. Looking forward to the next video :)
looking at the design I have some ideas for the reasons of the result based on control modeling of oscillating systems. I think part of the problem is the stable points of the system at rest, the rest state is not at the middle, but either to the right or left of the middle. It is analogous to a ball having to roll uphill to go through. A nice way to think of the forces necessary to move the LEDs is a hill in the middle with two hills on each extreme, you don't need any force to get the flexar to the right or left equilibrium points, as long as the flexar is at this region, it tends to the equilibrium. The problem I see with this design is that you need more force to get from one side to the other, while the magnets are further from the coil, since from one side to the other there is an uphill. The optimal design would look closer to a ball rolling on a parabola, which implies the stable equilibrium being right in the middle, that way it would not need much force exerted at the apex, just enough velocity to cross. I think that means a stiffer connection in the flexing region, but in stead of just making it stiffer, I think this and another problem could be solved by adding one or two more coils at the tip. More coils meaning more connections, I suppose the mass change from one more coil would be close to negligible compared to the LEDs and overall the stable point would move towards the middle. This would also probably solve the oscillations around the connection with the flexar, making the long exposure image closer to a grid. If you want to know the exact stiffness you need, and maybe even apply some closed loop control, you can model the system with some differential equations, I think it would look something like the equation for a mass with springs and dampeners on each side.
I think that instead of trying hard with insanely big magnets to increase the force, it would be more efficient to design the flexible part as a mechanical oscillator, tune it to particular frequency and increase Q-factor. Then the force (and thus the magnet size and coil current) required for keeping the oscillations will be orders of magnitude less.
Maybe you can combine PCB and fiber optic and put LEDs behind the scenes. The result could be more flexible and even more illuminated dot on tip of the PCB.
i think the bending would damage the fiber optic 😂
That is cool 🔥 , my suggestion : it is soft to use , make is tough then it will work fine, hand like structure .
Nice video!
Have you concidered different wave forms may make it oscillate slower but could provide more torque thus allowing faster oscillation with LEDs attached
What about adding some kind of rigid but "flappable" supports? Like a small 3d-printed smiley face (or crescent moon) that goes around the PCB and attaches to some bearing-based hinges at the center of the base? I think you'd get better support for the bend point to reduce wear, as well as save strain on the rest of the parts. I know it's not just floating in air...but if moving fast enough, and the support were thin enough, it'd be the same effect.
I noticed that the moving part of the FlexLED was sort of rotating/twisting around the single connection, to mitigate that I would recommend trying two flexible "stems" leading to the semicircle
i think that would improve it :) maybe some tracks could pass through them as well making the middle arm thinner
Increase the spring stiffness so that the resonance frequency of the system with the additional mass of LEDs is close to your excitation frequency ! You could propobably make a cheap custom leaf spring out of stainless steel PCB stencil, make a few different dimensions for peanut and try it out !
The problem your running into could be related to the Lorentz force. In a nutshell it says, that when youre moving electrons through a magnetic field, a force in the oposite direction to both appears. As this needs energy, it must get that from somewhere, so it slows the movement down. (Lenz's law). Therefore by increasing the strength of your magnetic field, you higher the lorentz force and therefore lower the velocity.
You should wrap a soft coil spring around the middle part of the system
Woaw, very cool!
Thanks! 🙂
I suggest you to use an 360 Arc made of 3d print and a shaft in the middle. It is important to use a counter weight to balance it.
Is it possible to add some thin material such as ribbon or tape to reduce the twist on the flexible portion as it oscillates, it seems like a lot of the momentum is lost in the arms acting as a form of inertial dampener. If they were connected to the same axis as the pivot, would it allow for better recovery before going the inverse direction?
Fantastic video as always, you are a true electronics artist
I would suggest you to use thick or wide flex cable which is between the LEDs and the base.
I see three main problems here: Stiffness of the base fles(the pivot), unwanted torsion which destabilizes the system and an electromagnetic coil too small for the applicaition.
So I would recommend that you do the following:
A: Increase the width of the pivoting flex by quite a bit, which allows for a stiffer board and less torsion and
B: perhaps adda couple smaller coils next to the main one or reshape the one you already have to have a more even force applied onto the flex by the magnets
An approach I've seen with similar systems in the past is gradually increasing the stiffness of the fles the closer it gets to the base, this reduces unwanted torsion, allows the bend radius to still be very sharp and increases the natural resonant frequency of the system(which means the display will naturally oscillate at a higher frequency)
There's issues with these approaches as well, mainly with adding more coils which would also add quite a bit of weight in a far point of the fulcrum, which would make it harder to push, but you're also exerting a higher force on the system, so it might balance out in the end.
Best of luck!
This is super cool! Looking forward to where it'll go. :-)
Regarding the flapping frequency, I've got an idea, that might do something (but I'm no expert). What if you had the connection at the ends of the arc instead of in the middle? That would improve aerodynamics a little and restrain the half dome movement more since the flexing part is smaller and will be "squeezed" less and bend more. Additionally, having the flexing connection at the sides of the arc would restrain the LEDs in any unwanted rotary direction a bit more. This would also mean a springier / stiffer motion, which might help push the arc back into the middle position more easily. This method might induce material fatigue tho.
Use a full half circle piece of transparent film to give a better “hinge”. I have to assume the inefficient hinge is causing it to flop randomly, making it hard to sync up.
This looks so cool! What is your long term goal for this project? 😁
Very cool
keep it up , you are amazing
Ohhh I saw the cut on your thumb, Carl. I assume that it was there due to the support removing process of the 3d printed part, not the magnet =))
Might I suggest putting the actual LEDs inside the base and using mono filament line (cheap for testing ) later Fiber optic fibers running along the stem and out to the locations on the semi-circle - might be an easier build in the long run. This might allow you to have many more "LEDs" and reduce the overall weight ..
Can you release just a sound byte of the display flapping. Its an adorable sound.
I was kind of looking for a way ot make an actuator. Had an idea to use the led pcb strip from a virtual boy to make 180 degree AR display. But having a hell of a time finding a method of moving the display.
You could make a big improvement by having two stems for lateral stiffness and a more efficient and uniform motion would result.
Consider adding some stiffness to the PCB section that acts like a spring. It seems like it might be worth investigating what frequencies you can achieve if the pcb sits at rest 90 degrees, perpendicular to the magnet surface.
awesome project. I'm no expert but it seems like it could work better if you added diameter support across the circle segment where the LEDs are so that the ends wouldn't flop around as that movement could counter the resonance.
Have you ever try rearranged the magnets for the Halbach array? could be useful
And that's why we just mount LEDs to a rotating strong mounting surface to do the same thing. Put a box around the rotating mount and all it safe an the motors will last longer than a flexible display.
with stepper motors and threadless you can make a system that accurately approximates the magnets without getting hurt.
i feel like you should take into consideration also the self vibrating frequency of the flapping stuff. for example, why not connect the extremities of the LED semicircle to the center, with a small piece of pcb? it would make the flapping pcb behave like a single part. with the current design you have several modes of vibration that interfere one with the other and makes it more difficult to move.
Just an idea, but could you use a double-sided hemisphere? Two semi-circles of LEDs that move from flat and meet in the middle (vertically straight up)
You should try with a more rigid bridge, then if you manage to design your "pendulum" with a resonant frequency in the right range you should be able to drive it at it's given resonant frequency more like a spring attached to a mass.
Hi Mr. Carl,
You can use mobile phone size leds and create a 3d computer or a 3d holographic screen
This could be revolutionary.
Like others, this project of ours also blew my mind
keep the good work ... :)
i did use super tiny leds in my v2 :) th-cam.com/video/wM_Byrv9iBI/w-d-xo.html but the leds were super fragile and brook under stress
the ribbon cable is a bit narrow? you could make the ribbon from the LEDs to the board wider or add supporting ribbons to reduce wobble. you could probably get it faster then
i think in mi ignorance that if you put a suport in the far parts you could get an stable flip and other thing i notice is the bend of the conector if you slighty reinforce may be could work
its a pain the i cant send and img to explain my self,
good luck and i will be waiting for the next video
ps sorry for my english
a big problem is that you have only one hinge point, so the thing is really wobbly. maybe you can make a design like the first flex-display, but with two tails and the spools further apart?
I think additional spools are necessary here because you are trying to move more leds with only one spool instead of the two you had in the first display.