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
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.😀
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
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!
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.
@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?
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.
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:)
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
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.
Could you add a hinge between the two magnets and control the angle with a motor? I think that way, you could dynamically adjust the angle and the strength of the magnetic field, and have more control over the frequency, efficiency, etc.
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.
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
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.
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.
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.
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)
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
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
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
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.
maybe you should make it stiffer as when the middle of the flexLED is already "bouncing" to the other magnet the endings of it are still going in the opposite direction thus slowing everyting down pls correct me if I'm wrong
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
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 am curious why you don't include flexible hinges at the ends of the led arch? It might help with magnet alignment and keeping the led path straighter...
Have you concidered different wave forms may make it oscillate slower but could provide more torque thus allowing faster oscillation with LEDs attached
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.
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.
Do you need the coil so high up the "stalk" of the device? if it were closer to the base (or maybe halfway down), it would be in a much stronger field area, and wouldn't need to travel as far (lever principle). You might need to make the upper portion of the stalk rigid if you did this.
would there be an easy way to adjust the "springiness" of the arm? it seems that the flex arm loses all momentum hitting the magnet and has to accelerate itself at the beginning of each cycle. a springy arm might slow down the arm before it gets to the magnet and use that energy to push it into the next cycle, but you would have to adjust the frequency and springiness to match
Can the actuators handle higher currents when they are constantly in motion? Edit: have you considered trying some kind of ferrite instead of steel? (this whole project is so cool, i definitely want to use these at some point)
Thanks! Higher current means more heat.. It might cool off with the flapping but I never tested that in more detail.. I made some core testing in the last video 🙂ua-cam.com/video/XfVz9Otxzyo/v-deo.html
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.
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.
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.
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.
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. ❤👍💪
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.
Looks great! Does the firmware control the strength of the field depending upon its position in a similar way to FOC motor control? I think this method would give the optimal performance.
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.
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.
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.
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.
I know this is an old video, but does the magnetic field change enough to be useful if you connect the bottom sides of each pair of magnets with some steel? Either as a slightly thicker steel sheet, or a full-on bar?
Nice project , Why you didn't fixed the led from the tow edges , so it oscillate only in the desired direction , or try to rotate them with a DC motor so you can obtain a spherical display .
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
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 ... :)
Hi, May be you have to try this.... Try small magnet( in stand of your pcb coil) on flax pcb and coil in stand of magnet( bigger magnet which is use for magnetic field). Give control signal to this two coils.
Would having the coil further down help? What about having multiple coils, maybe one lower down to help start it learning over? If you used multiple coils, would size make a difference, eg larger coil with a big coil above it?
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.
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!
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 :)
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
good experiment ... i have a suggestion. it looks like your two long flex arms are not balanced and also the central flex arm is a bit thin. the thin arm is adding to adding to the uneven movement at the sides. have you tried increasing the width of the central flex arm? or maybe having two or more central arms supporting the hemisphere. im sure you can get the frequency up that way...
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!
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?
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.
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.
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
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
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
The long exposure image looks like a scifi mapping of the human brain!
It does 😂
@@CarlBugeja It's really cool
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
"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
“Evil Villain Machine” is a great phrase. Every sketchy looking device you make should be labeled that!
😂😂
Evil villain machine "Name"-Inator of course
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!
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!
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 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.
So much hard work. Congratulations. Seeing all this I would have change to a rotating led cylinder or barrel for much higher frequency.
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.
@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?
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.
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:)
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
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.
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 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
Could you add a hinge between the two magnets and control the angle with a motor? I think that way, you could dynamically adjust the angle and the strength of the magnetic field, and have more control over the frequency, efficiency, etc.
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.
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
This guy doesn't lose the hope 👍🔥
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.
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.
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❤❤❤❤❤❤❤❤❤❤
New channel logo, nice
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)
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
Next rendition of the flex LED arc, make the LED contacts in a different orientation.
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
Cool experiment with the new geometry! Excited for version 4!
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
You have a new sub in me my man. This is next level project building. Thank you for filming it!
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.
maybe you should make it stiffer as when the middle of the flexLED is already "bouncing" to the other magnet the endings of it are still going in the opposite direction thus slowing everyting down
pls correct me if I'm wrong
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
It might help to have two _stems_ instad of just one. It won't be as flimsy maybe.
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 really enjoyed this video, i loved the editing, the pacing, and the project itself! great video Liked, and subscribed
I am curious why you don't include flexible hinges at the ends of the led arch? It might help with magnet alignment and keeping the led path straighter...
How about changing the PCB so it hinges (and transfers power through the edges of the arc rather than the center? Will be much more stable.
Have you concidered different wave forms may make it oscillate slower but could provide more torque thus allowing faster oscillation with LEDs attached
More power to you brother. Very good work and progress 👍👍
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.
I suspect if you link the edges to the middle, and widen/bifurcate the vertical support you'd get better results!
Man keep up the good work i can't wait what improvement you might do next
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.
Do you need the coil so high up the "stalk" of the device? if it were closer to the base (or maybe halfway down), it would be in a much stronger field area, and wouldn't need to travel as far (lever principle). You might need to make the upper portion of the stalk rigid if you did this.
would there be an easy way to adjust the "springiness" of the arm? it seems that the flex arm loses all momentum hitting the magnet and has to accelerate itself at the beginning of each cycle. a springy arm might slow down the arm before it gets to the magnet and use that energy to push it into the next cycle, but you would have to adjust the frequency and springiness to match
I would suggest you to use thick or wide flex cable which is between the LEDs and the base.
Have you ever try rearranged the magnets for the Halbach array? could be useful
Have you tried the full led aray in a vaccum, you are creating a lot of drag with ambient air?? Just a thought?
Can the actuators handle higher currents when they are constantly in motion?
Edit: have you considered trying some kind of ferrite instead of steel?
(this whole project is so cool, i definitely want to use these at some point)
Thanks! Higher current means more heat.. It might cool off with the flapping but I never tested that in more detail.. I made some core testing in the last video 🙂ua-cam.com/video/XfVz9Otxzyo/v-deo.html
I love this project, I hope you keep working on it because It'll be really cool if it works as intended,.
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 😂
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.
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.
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.
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. ❤👍💪
Have you concidered putting smaller coils on the branching Arms of the LEDs?
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.
Looks great! Does the firmware control the strength of the field depending upon its position in a similar way to FOC motor control? I think this method would give the optimal performance.
thanks! at the end the coil was being driven on/off as the duty cycle signal testing i made at 4.35 didn't improve it
Question:
Why are the leds in a semi circle ? Why not straight? Will be easier to keep level when flipping and you can set multiple flexled closer
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.
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.
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.
Can you release just a sound byte of the display flapping. Its an adorable sound.
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.
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 =))
I know this is an old video, but does the magnetic field change enough to be useful if you connect the bottom sides of each pair of magnets with some steel? Either as a slightly thicker steel sheet, or a full-on bar?
Very cool video, cant wait for continuation! Maybe electro magnets would help? If not atleast they would be less scary than those mega magnets! 😅
Nice project , Why you didn't fixed the led from the tow edges , so it oscillate only in the desired direction , or try to rotate them with a DC motor so you can obtain a spherical display .
I wonder if air resistance may be significantly affecting (dampening) the movement..keep up the good work!!
Have you considered using fiber optics to carry the light from LEDs on the base instead of putting LEDs directly on the flexiPCB?
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
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 :) ua-cam.com/video/wM_Byrv9iBI/v-deo.html but the leds were super fragile and brook under stress
Would you mind adding link to magnets in description please? Thank you in advance.
Hi,
May be you have to try this....
Try small magnet( in stand of your pcb coil) on flax pcb and coil in stand of magnet( bigger magnet which is use for magnetic field). Give control signal to this two coils.
Would having the coil further down help? What about having multiple coils, maybe one lower down to help start it learning over? If you used multiple coils, would size make a difference, eg larger coil with a big coil above it?
Does the magnet also push the body back? That would help it to go back to middle position.
Great work👍🌹 but I think you should use the mobile phone LEDs, they are so light , good luck
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.
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.
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!
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 :)
Lower the volume of the music please, I can barely hear you
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
good experiment ... i have a suggestion. it looks like your two long flex arms are not balanced and also the central flex arm is a bit thin. the thin arm is adding to adding to the uneven movement at the sides. have you tried increasing the width of the central flex arm? or maybe having two or more central arms supporting the hemisphere. im sure you can get the frequency up that way...
This looks really cool, will we ever be able to buy these?
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!
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?
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.
Would some sort of flex hinge on the ends of the led-arc be a possible solution for the stability problem?
There any way you could hook up small fiberoptic or glass fiber to the flex pcbs? Offset the led limitation to elsewhere
You should wrap a soft coil spring around the middle part of the system
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.