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View Full Version : All-in-one flashing LED light for my bike



mattthemuppet
10-22-2018, 03:45 PM
this light is like Grandpa's axe - this is its 3rd iteration (at least), with 2 different LEDs, 3 different batteries and countless switches. It's also the most important rear light on my bike as it is both on (distance perception for approaching drivers) and flashing (to get their attention). It even has a double-double flash which I wrote the code for myself. Only took me a year to learn how!

anyway, this is the old one - charger was failing and the switch was on the way out (turned the light off on bumps)
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3753&d=1540236637

it's what I call a "sled light", where all the components are attached to a sled(s) that then slide into a tube. Super simple to make, even with hand tools, and relatively light. PITA to service though.

starting materials

some random alu scrap, some scavenged batteries (3 for a total of 4Ah) and a microUSB charging+protection circuit
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3754&d=1540236650

some 1.5in square tubing from the scrap yard
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3755&d=1540236661

mattthemuppet
10-22-2018, 03:47 PM
got to go teach lab, I'll post the rest tonight or tomorrow :)

mattthemuppet
10-22-2018, 03:52 PM
still had coffee to drink, so here's another post

pocket for charger milled out, then hacked out with a Dremel and carbide burr, plus a couple of screws for extra security
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3756&d=1540236673

milling some slots in the back, plus the switch and charger hole. impromptu machinists jack stopped the whole lot from singing too badly
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3757&d=1540236686

sled and housing finished and polished prior to anodising
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3758&d=1540236704

ta da! Didn't come out bad. The mystery tubing allow didn't anodise as well, some smut and it didn't take the dye as deeply. Next time I'll anodise different parts separately so the settings are right for each part rather than the whole assembly.
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3759&d=1540236719

mattthemuppet
10-22-2018, 09:46 PM
starting the wiring process
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3760&d=1540236734

showing a whoopsie where I cut deeper than intended while carving out the charger hole and cut into that when I did the o-ring groove. Nothing a bit of JB weld can't cure
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3761&d=1540236747

driver holder. Fatigued solder joints has been a major source of problems with the previous versions, especially as this light sees a lot of road vibration, so this should reduce any chance of wires and parts moving relative to each other
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3762&d=1540236760

LED star installed. These are relatively old XP-E red LEDs. The new XP-E2 LEDs would be brighter still. The star is parallel wired so the forward voltage is the same as 1 LED (about 2.5V) and the current draw of each LED is 1/3 of the output of the driver (~1.8A).
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3763&d=1540236773

mattthemuppet
10-22-2018, 09:51 PM
everything installed. Didn't take pics of the finished wiring job as I was trying to get everything finished before dinner. The 3 batteries only just fit.

Clear part is made from 2 pieces of lexan, one bored to fit the optic, 5 minute epoxied together. Then the edges were milled to send some light back and forward at an angle to increase side visibility.
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3764&d=1540236792

the back
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3765&d=1540236804

front on view
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3766&d=1540236818

Cateye clip on the bottom and extra screw to increase thermal transfer from the sled to the housing
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3767&d=1540236830

mattthemuppet
10-22-2018, 09:53 PM
on full
http://bbs.homeshopmachinist.net/attachment.php?attachmentid=3768&d=1540236842

I was happy to have this riding home in the rain tonight. I'm much less worried about being hit from behind with a couple of bright lights out back.

Now to get back to the front light!

Joel
10-22-2018, 10:47 PM
That's a slick little package. Good idea to mill the edges of the Lexan.
Does just the O-ring seal it up tight (looks like maybe some silicone grease there) or did you use silicone sealant or similar?

mattthemuppet
10-22-2018, 11:20 PM
thanks Joel! I have plenty of time on the bike to think about stuff and each iteration improves upon the previous :)

I couldn't tell you how tight the o-ring seals things up, but it should be pretty good as I went through a lot of attempts to get the o-ring short enough (started with 1.5mm stock) that it would compress sufficiently for the light to go together. The clearance is about 0.1mm and the o-ring groove depth is 1.2mm so there should be ~0.2mm of squish to fit. It also got a slathering of silicon grease to help it go together and seal it even better - what you see at the bottom is the leftovers. Plus I was worried about how well it would seal in the corners and I'm a belt+braces type when it comes to resisting the weather..

No silicone sealant on this version, I've had to deal with that on my other sled lights and it's a real pain to disassemble and reseal them.

BCRider
10-23-2018, 12:59 PM
Superb!

I mentioned in your previous thread that I'm an ex bicycle commuter too. My route had me only crossing major roads and not riding along them. All my street riding on my route was secondary streets. Still enough traffic on those streets to take comfort in knowing a good blinking red light is back there guarding our six though.

I guess the smut and color difference you can see doesn't come across in the pictures that well. I think the anodizing looks fantastic.

mattthemuppet
10-23-2018, 02:47 PM
thank you! Yes, I remember the conversations about lights, rust and rain :) What really got me pushing the work on this light was riding home in torrential rain last week - if I was struggling to see where I was going then everybody else was too! By and large drivers will give me more room, especially when passing, when I have this light going. I've also been told by colleagues that it's easily visible from at least 1/2 mile away, so hopefully it'll catch the distracted drivers in the few seconds they're not looking at their phones..

I think the anodising turned out ok, especially for my 1st go with a proper dye. At the end of the day, it's there for protection/ durability as much as looks, and I think it'll do that just fine. It'll probably end up more of a pink after an SA summer though :)

BCRider
10-23-2018, 03:13 PM
....t'll probably end up more of a pink after an SA summer though

Don't EVER say "pink". Real men call it "salmon".....:D

Depends on the quality of the dye. What I've seen on older anodized aircraft fittings is that they stay red but the sun bleaches out the red and more and more of the silver shows through. It's like the color stays red but just turns thinner.

I wouldn't want to oil it but what about some of the new automotive waxes? The ones that are not creamy looking? Look for something that says "leave no white residue" or words to that effect. I've got some that goes on clear and doesn't haze as it dries. I've tested a small patch then used it on my matt finish Moto Guzzi gas tank to give the matt clear coat some protection. Worked like a charm. Might just block some of the UV and slow down the sun bleaching?

.......Might want to give that poor machine the light sits on a cleaning and go over with the same stuff while you're at it..... :) neener neener :D

I recently used up my bottle of Eagle One brand Nano car wax which fit this bill and it was superb. But I can't find it in my local automotive shops any longer. I'm now using Turtle ICE which is just as good to apply, leaves no white residue (so no super fine polishing compounds which is what I'm trying to avoid) and is almost as long lasting as the Eagle One stuff for rain shedding.

3 Phase Lightbulb
10-23-2018, 03:31 PM
Since I sit in my office 8-9 hours a day and the only exercise I get is walking around the house I decided to get one of those exercise bikes that fit under your desk allowing you to pedal like a fool while working. I'm trying to get into a habit of peddling it as often as possible. It's completely silent so the only thing you hear is my legs moving and my chair making little squishing sounds as my legs lift up and down off the edge of my chair. I wonder if it basically gives you the same workout as a regular bike ride?

https://images-na.ssl-images-amazon.com/images/I/71LBNJfRl9L._SL1500_.jpg

http://www.bbssystem.com/pictures/bike2.jpg

mattthemuppet
10-23-2018, 03:52 PM
BCRider - my bikes are clean on the inside :) The dye is from Caswell, so it should be pretty good. At the end of the day, if I don't like it in a few years time I can take the front out, strip it and do it again. Having the means of production takes away alot of those worries.

3ph - it's not going to hurt, that's for sure. You won't get as much exercise as on a bike outside, as a big part of the effort is overcoming wind resistance, but as the long as the blood is flowing and you're warming up, you're exercising!

3 Phase Lightbulb
10-23-2018, 03:58 PM
3ph - it's not going to hurt, that's for sure. You won't get as much exercise as on a bike outside, as a big part of the effort is overcoming wind resistance, but as the long as the blood is flowing and you're warming up, you're exercising!

I can turn up the resistance on the floor cycle but if I set it too high I actually need to grab onto the desk for leverage to complete rotations which is a little too intrusive as I'm usually hacking away on my keyboard or on a conference call while peddling. I can still set the resistance high without needing to grab onto the desk but I find it wears me out too quickly so maybe once I get into shape I'll be able to raise the resistance.

BCRider
10-23-2018, 09:36 PM
3PL, if it makes your heart beat faster and you need to breath deeper and more often it's exercise. And as he says some is certainly better than none. Set it to a level where you can pedal more than not. Even if it's a lighter load more time at it adds up.

Years ago I tried running/jogging. Hated it. The most boring thing I could think of short of staring at a wall. But for some reason I LOVE cycling. But not on the stationary stuff. I need to be out pedaling and seeing the scenery go by and banking into the turns..... which would dovetail with the motorized other half of my username interests. And it doesn't hurt that the bicycles when used for commuting need their own share of mechanical quality time. So I get to tinker with them too.

mattthemuppet
10-24-2018, 01:21 PM
I can turn up the resistance on the floor cycle but if I set it too high I actually need to grab onto the desk for leverage to complete rotations which is a little too intrusive as I'm usually hacking away on my keyboard or on a conference call while peddling. I can still set the resistance high without needing to grab onto the desk but I find it wears me out too quickly so maybe once I get into shape I'll be able to raise the resistance.

depends on what your aims are. for muscle strength, high resistance and slow cadence are what you want; for anaerobic capacity, low resistance and spinning so fast you spin off into space are ideal. for burning calories and increasing general aerobic fitness, a resistance and cadence that lets you speak normally but warms you up without wiping you out are what you want. As long as your heart rate goes up, you'll be doing better than just sitting there :)