Light Periscope/Candy Cane

syc

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Joined
Jun 10, 2008
Messages
155
I wanted a light to provide extra visibility after dark for the Burley I haul my son around in, and after looking at some of the glowire and similar options friends were using on their Burleys, I decided to make a waveguide and bond it to an relatively bright light source - the glowire is pretty bright, but not nearly as bright as an LED through an optic.

Eventually, I settled on a 1" clear acrylic rod from TAP Plastics, and a Superflash clone from PricePoint. Both were inexpensive enough so that if it was a bust, I wouldn't be out too much money.
It actually turned out very nicely and I thought I'd post some quick photos in case anyone else wanted to try something like this. Its kind of like a giant version of the "Angel Eye" headlight ring that you can find in the archives. I can take some more photos if people are interested.

Here's a side view of the light:


Here it is from the front:



I didn't have exposure control on my point and shoot, so I don't have a proper picture from the rear (basically all you would see is a big red dot, and without manual exposure control I didn't think there was a baseline to compare). I can probably setup an MTBR forum standard exposure if people want to see it.

Here's a picture of the acrylic rod after I pulled it from the oven. I built a little "jig" to support most of the rod, but allow the rest to sag from its own weight once the acrylic got soft enough. It took maybe 20 minutes in a ~325 degree oven for it to bend down to around 90 degrees.



I then took a dremel and cut a shallow groove along the circumference of the rod a few inches below the bend, so that some light would be deflected out and be visible from the front and sides. You can see these bright bands on the front and side views.

I used clear acrylic adhesive from TAP Plastics to bond the waveguide to the front of the blinker, covering up the optic for the main 1/2 watt emitter. It does a pretty good job of catching the light ad directing it along the waveguide.

A little 3M reflective tape in between the bright bands adds some reflective surface in case the red light is drowned out by a headlight.

Figuring a way to mount the light was actually more work than making it. In the end, I just went with some P-clamps mounted to the frame of the Burley with small screws.

I get lots of positive comments about the visibility from bike commuters who ride by - a fellow baby towing parent that I sometimes ride home with from daycare thinks it looks like a giant candy cane. My son gets a kick out of it - I think he's a budding light geek...

Steve
 

panicmechanic

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Joined
Nov 23, 2009
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130
Location
Germany
syc, that's brilliant! Hope it scares the hell out of any motorist for not knowing what he is approaching.
I don't have a trailer, but I'll bookmark this idea for future abuse. Have you tried with an LED only in a drill hole in the acrylic, before going to this superflash-type light?
Hey, what else do you expect your son to become :poke: :D
 

syc

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Joined
Jun 10, 2008
Messages
155
Have you tried with an LED only in a drill hole in the acrylic, before going to this superflash-type light?

I thought about it, but with these Sette blinkers going for about $7/each, it seemed a lot easier to buy one of them and not play around with a driver, and working out the enclosure, etc...

But when I was testing out the acrylic rods with a shorter section, I put the emitter into the end of a rod to see how it worked. The issue that comes up is that the rod seems to transmit the beam pattern that enters one end, out the other. So if you have a narrow optic on the emitter and point that into the rod, you seem to get a narrow beam out the other end (taking into account the diffusion from how the rod is cut on each end). If you just put the bare emitter into one end and have an even cut on the exit side, then I think you're going to get the beam pattern of the raw emitter, which is pretty diffuse to begin with. That may or may not be what you want.

I'd like to get my hands on some inexpensive side emitter fiber optic - it would be really handy for some lighting projects.

Steve
 
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