mountain_lion

So no topo map? I guess you need to buy that extra if you want it. The new DEM maps sound interesting. Have not seem that yet. Anyway, for now my 305 and/or my Etrex Legend HCx with my own topo maps loaded will have to do.

Which maps come bundled with the 705 when bought in SA? mountain_lion2008-05-14 15:05:55

I do not own a 705, but I have been using GPS for a few years. Main disadvantages of the Edge 705 in a car is: - small screen; difficult to view while driving - no external antenna (less of an issue these days with the improved reception and firmware). - not easy to mount (although with the 305 I got 2 handle bar brackets; could try to make a plan with one for the car). - no voice prompts

If it is only batteries you want to charge, then get a charger that runs from 12V which you can power straight from the car battery / cigarette lighter. No need for an inefficient inverter. While you are at it, get a charger which charges the cells individually rather than in set of 2 or 4. This will increase your battery life and performance. e.g. Hahnel PowerStation QUATTRO Comes with 4 AA NiMH cells.

Just drill out the hole in the rim. Much better. It won't do any harm. You have to enlarge the inner hole in any case to create enough space for the thicker bit of rubber around the valve stem.

Where does one buy a Cree Q5? I want to know that too. Been looking for a while. I have only found one UK site selling Q4s. Cree LEDs do not seem to be easily obtainable in small quantities. 1W Luxeons I could order online from a local SA supplier, so they will have to do for now.

Thanks BL, but your light deserve a thread of their own. This is the DIY thread. Please post more info on your lights and your latest projects so that we can discuss later (I am off to bed now).

I just wanted to make sure that you had the time right. That is a bright light, even at F2.8, 1/1.3s is not a long opening.

See this thread as well as http://reviews.mtbr.com/blog/category/lights-shootout http://gearreview.com/LEDs08_intro.php

OK, I see you added the beam shot photo now. What lens opening and exposure time did you use for this photo?

Brighter-lights, was there supposed to be photos in your post above? Does not show for me. I knew most of what you say above before I even started with this project (this is not my first DIY light). However I am sure that you will understand that part of the reason for building your own light is just the satisfaction and challenge of doing it yourself. Battery + charger has always been the most expensive part for bike lights. That is why I have been using sealed lead acid batteries for my previous DIY lights. Heavy and not very efficient, but cheap and easy to charge. I still have a few 6V, 4Ah batteries giving good service. Unfortunate that the power LED's forward voltage is such that you can will struggle to drive 2 LEDs in series from 6V. I like your thinking though and at the prices you mention above, I am certainly interested... Please post more info on your website, or start a thread where we can discuss these new projects of yours. A light weight helmet mount light to compliment bar lights (does not have to be super bright) will be really nice to have.

Which charger have you got and where did you buy it?

OK, finally some pics of the light mounted on Mrs mountain_lion's bike. Front view: Side view showing mount and battery pouch: Pilot's view: Under stem mount keeps the light out of harms way with an uncluttered handle bar. Note the dimming switch on the right of the bar: Because of the short stem that she is using, I had to improvise a bit to get the old flasher mount fitted. A piece of wood with some holes drilled and attached with a cable tie (which has since been trimmed) did the trick. Mrs mountain_lion used the light for the Dirtopia night ride and it performed well.

The specs says AA & AAA. This charger gets good reviews on the net. I think I will order from an eBay dealer.

BL, I agree with you on the battery issue. If only lithium-polymer packs were not so expensive... I opted to use NiMH AA's for my DIY light, one of the reasons being able to charge individual cells. I especially got a more expensive charger which charges the cells individually. Unfortuneatly the market also wants cells to be charged as fast as possible and thus most chargers use a higher than optimal charge rate. With my home made lights now using 8 NiMH AA cells each plus cameras GPS and other electronics all wanting charged batteries, I need more charging capacity, I am considering getting the Maha C800S charger. Ebay seems to be the best source; have not been able to find it or anything similar locally in SA. This charger has "soft" / slow charge option, which will extend battery life. I am not sure how much of an issue "battery balancing" really is. I guess it depends very much on the type of battery, but from using my 4 cell individual cell charger, I know that charging time does differs for individual cells.

WH, http://www.brighter-lights.com/bike.htm has got the prices. Does not look bad. Even got an option to provide your own battery. If I had to buy a light set, this looks like an serious contender (along with Nightlighting). BL, I assume you import your own Cree LEDs; I have not found any local retailers that stock them. Would love to fit some Crees in my DIY light.

I have not done a runtime test yet either. We are only driving the LEDs at 600mA, so in theory the runtime from 2700mAh batteries = 2700 / 600 = 4.5h. However the battery manufactures tend to be optimistic about capacity and also base their values on low load currents, which give longer battery life cycles. Still, excluding 24h races, run time of more than 3h will not often be required. 600mA x 3h = 1800 mAh. I am sure you should be able to get at least that out of a cell rated as 2700mAh. My dim setting reduces the load current to 300mA, which doubles the run time.

Indeed ! I have enough pipe for another 50 lights' date=' but it's the cheap bit unfortunately Nah, no good building this for other people. The fun is in building it yourself and riding with your own nuclear light source. Come on, order your bits and build your own. it's a fun way to spend a cold, wet winters day. Loads of those around soon. [/quote'] I agree, the fun is in building your own light. The time invested does not make worthwhile to build lights for others. If you want to buy a light, get one of the commercial products. WH, perhaps you can put your surplus pipe in the classified section. Flea seems to be interested in some! At least I did not have to buy pipe; still had some off-cuts left over from last years bathroom renovations.

I use the Buckpuck's control and ref pins to control the light. Open circuit (infinite resistance) between ref and control is 100% load current. Short circuit between ref en control is 0% load current (LEDs off). By varying the resistance between ref and control any % output current and thus dim level can be achieved. I have a fixed resistor (which results in approx 300mA load current). The 3 position toggle switches this resistor in or out for dim and high. 3rd position on the toggle shorts ref and control to turn off the light (there is still a few mA load on the battery in the off state, so I disconnect the battery before storing the light). I will still experiment a bit to see what is the best dim level. I want the difference between dim & bright to be sufficient so that on coming car drivers who do not dim their lights will notice that I am "flashing" them. mountain_lion2008-04-30 09:43:44

I found this heat sink in an old PC, Total over kill for 3 x 1W Luxeons driven at 550mA, but as you can see the tri-lens fits inside so nicely it just has to be done. (perhaps I can upgrade to 3W Luxeons later). So LED light version 2 will be attempted soon... Mrs mountain_lion has taken possession of the first set, so I need another for myself anyway...

The beam shots. The garden shed is approx 17 meters from the lights. The photos cover 15m, i.e. from about 2m in front of the bike. All photos 8 seconds @ F8 without any post processing. Control photo (no lights on): One of my previous DIY light sets using 2 x 10W Cateye lights @ 6V: A slightly modified 6V Vista Light set using 1x10W + 1x5W halogen lamps: Finally the new LED light with 3x 1W Luxeons driven @ approx 550mA (my high beam setting; I forgot to take a low beam photo ). I am still experimenting with the vertical aiming of the light. Note that beam shot photo's are just an indication since much depends on the camera settings used. 8s is the longest exposure that my camera can do. Longer exposure will also show up the lower level peripheral which is useful to show up the edges of the trail. In practice the lights are much brighter than in the photo's above and the new LED certainly out performs the other two light sets. mountain_lion2008-04-30 09:52:22

Here is my LED light after some time spent in my dad's garage: The guts: 8 x NiMH AA powering a 1000mA Buckpuck 3021 LED driver, soldered onto vero board with dimming resistor, 3 position toggle switch (off, high, dim) & connector for the LED wiring. The switch has a rubber cover and is mounted on the handlebar with a piece of inner tube. The driver board is also covered by inner tube for electrical isolation and protection against the elements. Batteries and driver are mounted on the bicycle frame in a pouch with velcro strap. I used an old PC CPU heatsink to mount the LEDs on. The heatsink was machined on a lathe to be a tight fit in a section of 50mm PVC pipe. The lens is held in place with a PVC coupling which was cut down on the lathe. 3x 1W Luxeon emmiters: The assembled light, which is attached to the bike stem with an old LED flasher mount: I will take some photos of the light mounted on the bike in day light and post later.

Nice WH! My first version was also completed over the weekend and had its first test ride earlier tonight. Works very well. Photo's and beam shots to follow shortly.