I saw a while back that someone had made a makeshift ‘flexible’ neopixel blade (I don’t remember where I saw it) but it got me thinking about making a very long neopixel whip.
Unfortunately the neopixel sticky strips aren’t really meant to bend over and over, let alone bend like a whip would need to in order to loop. I don’t plan on attempting to crack this thing but it should be very flexible.
Does anyone have any ideas for a very flexible neopixel strip, or know of any sources where I could potentially purchase it? Also, if anyone has a place to buy a flexible tube (silicone maybe) for the whip itself that would be great.
This would be hard, because you would need a solution that can be repaired when it breaks, and it will break…
A fairly durable way to do this sort of thing would be to use a small PCB with one neopixel on each side, then connect them together will silicon-coated flexible wires. Each PCB can then be encased in epoxy to make it durable. But of course, doing that also makes it very difficult to repair…
1 Like
I figured it would be something like that. What neopixel pcb would you recommend? Since I’m aiming for something long, I don’t really mind having the pixels spaced out, which might also help with flexibility.
Also, do I need silicon wires specifically? I’ve always used PTFE wires, are silicone ones more flexible?
I’m fine with repairs, since I don’t plan on doing much other than posing or lightly swinging it around. Definitely no dueling with this.
I would just design a small PCB and order a bunch of them from oshpark, not sure if there is something that exists already that might work though.
Silicone-coated wires are very flexible, which would seem to be helpful, but I don’t know if you need it.
The hard part about repairs is to make it easy to take apart and put back together again.
The only real feasible option I can see for that is to allow the entire thing to slide out of the silicone tube to do direct repairs, which I’ll have to figure out something for. I’ll ‘make sure to give updates of my progress later down the line.
Interesting idea: Use a vacuum pump to reduce the pressure inside the hose to hold everything in place. Release pressure to let everything slide in/out for repairs.
That’s an interesting though, and it would work… my problem is trying to get it to seal, since both ends of the tube are open and I need a way to cap one end.
I’m sure I’ll figure it out
Many types of plastics can be re-shaped with heat and permanently sealed by melting it together.
I don’t think you can do that with silicone though.
I’ll probably end up using a normal polycarbonate blade end on the end of the whip for convenience, I just have to be careful when swinging it around because that will definitely cause some damage.
If not, I’m sure I can find some sort of silicone end cap of the correct side if I look hard enough.
I also have to figure out how long I want it to be: the longer it is, the further apart the pixels will have to be since I’m trying to stay within the ‘normal’ amount of pixels per blade.
No need to stay within the “normal” amount.
I have a blade with 529 LEDs in serial which works just fine. 
It’s probably possible to just seal one end with silicone glue.
So after doing a bit of research into pre-designed individual neopixel units (I don’t know how to design my own PCB’s, I have fusion 360 but I have none of the knowledge needed to design a board) , I realized that unless I’m looking to spend hundreds on singular Neopixels, I should probably just use neopixel strips and deal with the consequences of using something that isn’t really meant to be bent a lot; the cost of fixing a single strip of leds dwarves the cost of even having to buy a couple of individual ones.
Finding a cheap, single (or double) neopixel ‘unit’ seems a bit too far from my price range for this is ‘fun side project’
EDIT: may have found one. Gotta check some things first.
Edit: nope, still ridiculously expensive
First of all; designing PCBs isn’t that hard.
Try kicad or fritzing, both are free.
Oshpark charges $5 / square inch. Let’s say 6 LEDs per square inch.
Oshpark would come in at $120 for 144 LEDs, and of course you would also need the LEDs themselves, and assembly will be quite a lot of work.
Another option would be to buy LED strips that have cut points in between each LED, then just build it from that.
Oh. I didn’t even consider that. Anything other than fusion 360 sounds good to me. It’s like a little box of nightmares in there.
I’m in the process of designing a PCB for these neopixels, but I can’t seems to find documentation on the resistors needed. I know that for data, a 300-500 Ohm resistor is needed between the blade and the first pixel. Do I need one for every other pixel as well? And I see other resistors but I can’t seem to find any info on it. I appreciate the help
No, you don’t need any resistors between pixels. You could add them if you’re worried about shorts, but they are not needed.
Depending on the type of pixels you use, capacitors may be recommended or needed between + and - though.
Be careful about resistance though. You’re going to be putting a lot of power though the wires, and possibly also through the boards, so big fat copper paths is going to be helpful. If the amount of copper is insufficient, you get power drops which will make the blade off-color or stop working near the end.
Got it. Also, do you have a go-to place to buy board components, such as resistors and in this case, neopixels? I can buy the resistors I need from TheSaberArmory but the neopixels will need to be purchased elsewhere.
Edit: I’m just going to the pixels from adafruit. Most likely the most reliable source from them anyway. I appreciate the help! Time to work.
mouser or digi-key for components