Five-spoked Wheels
#26
THE STUFFED


Joined: Oct 2009
Posts: 12,671
Likes: 21
From: San Francisco, CA
Bikes: R. Sachs Simplicity; EAI Bareknuckle; Madone SLR9 Gen 8
Totally get this one you will not regret it.
Nah if you want 5 spokes the aerospoke is the only feasible choice unless you're like bill gates....
AND no the aerospoke is not that heavy in real life; just in bikeforums where the aerospoke is looked down upon.
Nah if you want 5 spokes the aerospoke is the only feasible choice unless you're like bill gates....
AND no the aerospoke is not that heavy in real life; just in bikeforums where the aerospoke is looked down upon.
#29
THE STUFFED


Joined: Oct 2009
Posts: 12,671
Likes: 21
From: San Francisco, CA
Bikes: R. Sachs Simplicity; EAI Bareknuckle; Madone SLR9 Gen 8
Last edited by Leukybear; 03-29-10 at 10:47 PM. Reason: typos bah!
#33
I think it's great that you want to make your dream bike, but I think you should reconsider one point. You say this bike will be "just for show". I think that's the wrong attitude. You should require that the bike be rideable and moreover, fun to ride. This poses the problem differently for you: "how can I do all this crazy stuff I want to do, and still have a very functional bike?"
#34
It is funny ain't it? It's like showing off a beautiful suit that you can't wear. But OP just wanna art piece or something.
... But I know a lot of people get high on stuff like that. I know an artist (!?!?) drilled a hole on a bar stool and stuck a bike fork upside down with a front wheel. I dunno, but it just look like a heap of trash for me.
... But I know a lot of people get high on stuff like that. I know an artist (!?!?) drilled a hole on a bar stool and stuck a bike fork upside down with a front wheel. I dunno, but it just look like a heap of trash for me.
#35
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Joined: Mar 2010
Posts: 20
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Sorry for not being clear. The bike will be very rideable; it just won't be the bike I'd do a cross-country ride on. It will be a single speed (not fixie) with front and probably rear brakes (if only for handlebar symmetry). The lights will be programmed with different modes, and at least one mode will be a safety mode in which the lights function to make night riding safer like normal bike lights. Maybe I'll have strobes and nav lights like an airplane.
F***; I don't even know what this concept is going to be like when I'm done. I'm only now working on the proof of concepts now to see if I can get these LED's to behave properly. Between posts I've been working just to see how ONE RGB LED will look hooked up to potentiometers to adjust the color output, so it's gonna be awhile before this thing comes together.
F***; I don't even know what this concept is going to be like when I'm done. I'm only now working on the proof of concepts now to see if I can get these LED's to behave properly. Between posts I've been working just to see how ONE RGB LED will look hooked up to potentiometers to adjust the color output, so it's gonna be awhile before this thing comes together.
#36
Thread Starter
Junior Member
Joined: Mar 2010
Posts: 20
Likes: 0
So, this project is going to take a little longer than I thought. Last night I tried putting together a circuit board with only ONE RGB (red/green/blue) LED and potentiometers to control the colors, was only able to get the red portion to work with what, upon inspection, looked like incorrect wiring, so I 'corrected' the wiring, and then that same potentiometer smoked out on me (ha, I did get yellow light from it, though just before it burned out!). Now I'm remembering "diode circuits" was when I stopped giving a **** in circuits class. Hmm....
#37
Senior Member
Joined: Feb 2007
Posts: 1,414
Likes: 0
From: Central CA
Bikes: A little of everything
Does it NEED to be five-spoked? At night, all you're going to see is the lights. Get a wheelset with black spokes, give it another quick shot of matte black paint, and position the lights however you want them. Alternatively, build disks to attach to your standard wheels (https://nycbikepolo.com/?page_id=168)- the lights could be entirely removable from the wheels.
#38
Your cog is slipping.



Joined: May 2009
Posts: 26,053
Likes: 100
From: Beverly MA
Bikes: EAI Bareknuckle
So, this project is going to take a little longer than I thought. Last night I tried putting together a circuit board with only ONE RGB (red/green/blue) LED and potentiometers to control the colors, was only able to get the red portion to work with what, upon inspection, looked like incorrect wiring, so I 'corrected' the wiring, and then that same potentiometer smoked out on me (ha, I did get yellow light from it, though just before it burned out!). Now I'm remembering "diode circuits" was when I stopped giving a **** in circuits class. Hmm....
#41
So, this project is going to take a little longer than I thought. Last night I tried putting together a circuit board with only ONE RGB (red/green/blue) LED and potentiometers to control the colors, was only able to get the red portion to work with what, upon inspection, looked like incorrect wiring, so I 'corrected' the wiring, and then that same potentiometer smoked out on me (ha, I did get yellow light from it, though just before it burned out!). Now I'm remembering "diode circuits" was when I stopped giving a **** in circuits class. Hmm....
Essentially, you are "sinking" current to modify the bias voltage. You are kinda dissipating the energy so LED gets the right stuff. The idea is correct, but most potentiometers can't handle much dissipation; probably about (or less than) 0.5W, check spec sheet. P = V^2 / R so you can do the rest; probably you are at the max with it smoking and stuff. (V is voltage drop across the pot; not across the LED. Just subtract the LED voltage drop (2-5V or so) from battery voltage.) ... You might end up with workable results, but then most pots are thin wound wire on a thin board covered by polymer of sort. Totally vulnerable to heat. So if I were in your shoes, I would avoid that. (But I ain't you; so you can do whatever you want.)
Anyways, you could probably buy a LED regulator kit for RGB stuff that don't sink current on pots. It's probably cheaper.
#42
Well, you should start paying attention. Controlling bias current solely by potentiometer is a mistake.
Essentially, you are "sinking" current to modify the bias voltage. You are kinda dissipating the energy so LED gets the right stuff. The idea is correct, but most potentiometers can't handle much dissipation; probably about (or less than) 0.5W, check spec sheet. P = V^2 / R so you can do the rest; probably you are at the max with it smoking and stuff. (V is voltage drop across the pot; not across the LED. Just subtract the LED voltage drop (2-5V or so) from battery voltage.) ... You might end up with workable results, but then most pots are thin wound wire on a thin board covered by polymer of sort. Totally vulnerable to heat. So if I were in your shoes, I would avoid that. (But I ain't you; so you can do whatever you want.)
Essentially, you are "sinking" current to modify the bias voltage. You are kinda dissipating the energy so LED gets the right stuff. The idea is correct, but most potentiometers can't handle much dissipation; probably about (or less than) 0.5W, check spec sheet. P = V^2 / R so you can do the rest; probably you are at the max with it smoking and stuff. (V is voltage drop across the pot; not across the LED. Just subtract the LED voltage drop (2-5V or so) from battery voltage.) ... You might end up with workable results, but then most pots are thin wound wire on a thin board covered by polymer of sort. Totally vulnerable to heat. So if I were in your shoes, I would avoid that. (But I ain't you; so you can do whatever you want.)
An example of a low-power LED driver IC (may be still overkill for the OP) is this. Still, at $3.50 MSRP, it won't break anyone's bank.
#43
Thread Starter
Junior Member
Joined: Mar 2010
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Wow, guys, thanks for the really substantive feedback. I think I just need to take my time putting the whole thing together, learning from experience and heeding advice from people like you. I only took one programming class, one circuits lecture, and a circuits lab in college, so I've got quite a learning curve ahead of me.
As for why the first pot smoked out, I wired the thing up completely wrong. I thought the LED had a common cathode, but it actually has a common anode. I also wired it up with the leads from the pot wipers going to the ground. Stupid, I know, but this is why I'm starting small before putting the actual bike circuit boards together. I have a lot of steps to go before I can feel confident putting together the entire bike.
By the way, if I'm going to have possibly 1,000 lights on this thing, does anyone have any recommendations on a microcontroller and maybe something good to read for putting this kind of stuff together? Thanks for the help thus far.
As for why the first pot smoked out, I wired the thing up completely wrong. I thought the LED had a common cathode, but it actually has a common anode. I also wired it up with the leads from the pot wipers going to the ground. Stupid, I know, but this is why I'm starting small before putting the actual bike circuit boards together. I have a lot of steps to go before I can feel confident putting together the entire bike.
By the way, if I'm going to have possibly 1,000 lights on this thing, does anyone have any recommendations on a microcontroller and maybe something good to read for putting this kind of stuff together? Thanks for the help thus far.
#44
For example, a project for driving a 24x18 LED array:
Last edited by wroomwroomoops; 03-31-10 at 12:50 PM.
#45
Thread Starter
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Joined: Mar 2010
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Cool, man. Will do. Is that a picture of your project? Do you have an experience creating full-color LED displays where the LEDs are not simply on/off but the voltage to each one of the LEDs is finely controlled to produce full-color video animations (or just full-color animations)?
I realize I'm getting in kind of over my head, but what else is an unemployed aerospace engineer supposed to do with his time other than expand his engineering knowledge? I guess I figure I'll also have something to show for my being out of work for a few months when I go to interview again instead of having just vegged-out all the time.
I realize I'm getting in kind of over my head, but what else is an unemployed aerospace engineer supposed to do with his time other than expand his engineering knowledge? I guess I figure I'll also have something to show for my being out of work for a few months when I go to interview again instead of having just vegged-out all the time.
#47
Cool, man. Will do. Is that a picture of your project? Do you have an experience creating full-color LED displays where the LEDs are not simply on/off but the voltage to each one of the LEDs is finely controlled to produce full-color video animations (or just full-color animations)?
I realize I'm getting in kind of over my head, but what else is an unemployed aerospace engineer supposed to do with his time other than expand his engineering knowledge? I guess I figure I'll also have something to show for my being out of work for a few months when I go to interview again instead of having just vegged-out all the time.
I realize I'm getting in kind of over my head, but what else is an unemployed aerospace engineer supposed to do with his time other than expand his engineering knowledge? I guess I figure I'll also have something to show for my being out of work for a few months when I go to interview again instead of having just vegged-out all the time.
#48
I realize I'm getting in kind of over my head, but what else is an unemployed aerospace engineer supposed to do with his time other than expand his engineering knowledge? I guess I figure I'll also have something to show for my being out of work for a few months when I go to interview again instead of having just vegged-out all the time.
#49




