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Three because I was taking a guess at the forward voltage of the LEDs - I assumed they'd be around 3V - so 9V / 3fV = 3 ... so 2 LEDs wired in series would go pop, 3 wired in series would be ok Resistors for that bodge = none ... I think you're still worried about what resistors you've used on your car - so looking back at the LED specs you posted, they have a maximum forward voltage of 4V, and your power source was 5.0V ... so the resistor needed (assuming you use one resistor per LED, and all the LEDs are wired indivually - i.e. in parallel) is: ((Supply V - Forward V) / current draw in mA) * 1000 or ((5-4)/20))*1000 or (1/20)*1000 = 0.05 * 1000 = 50 ohm resistor or, if you assume a more normal fV of 3 instead of 4, 100 ohms ... Or if you wanted to use just one resistor & split the output from that 4 ways, the 20mA above would become 80mA - meaning you'd need a 12.5 ohm resistor ... |
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ok now im confused.com totally. i have only wired up 2 LED's for now as i am not convinced i want to drill holes in the front of the chassis to make it 4 as i cant see them shedding much forward light. i bought the 10ohm resistors as recommended in a previous post and as my last post states they run fine, and not hot so i am gonna stick with it for now unless i decide to add the other 2 on the front, then i will have a rethink
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My cunning plan to make the lenses didn't work - heating them up with a hot arir gun & using a small paperweight to get the shape worked - but they shrank unevenly & the scored lines disappeared
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The following user(s) Liked this: CrummeyGrasshopper
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Wiring for LEDs - I thought tapping into the RX was tidiest ... used the plastic bits from ball links as nuts for the lights as the machine screws I epoxied in weren't long enough - but it did give a handy place to secure the wiring ...
Top view ... side view - proportions don't look as good as the original Grasshopper - not enough in front of the front wheels (could be fixed by using the old skool bumper?) ... ... and way too much hanging out the rear ... If I were to do this again, I think I'd probably extend the body in the middle & make it a two seater ... Underside ... Lights do a fantastic job of lighting up the back of the front shock towers I have a sheet of re-re Grasshopper stickers I could put on - unusually, the precutting process was actually fairly accurate on that sheet ... but I'm undecided about using them - I like the look as it is, but the paintwork is a bit poor & could use the distraction ...
The following user(s) Liked this: CrummeyGrasshopper
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Last edit: by Jonny Retro.
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Bit the bullet & put the stickers on ... everything is where it should be apart from on the rear wing - I moved the grasshopper to on top of the power bulge & doubled up the text ...
... the slightly concave "reflector" bowls & hatched lenses do quite a good job of diffusing the lights into a useable headlight pattern ... which is then totally ruined by the shock towers ... Anyway - another car to the "done" line |
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