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  1. #1
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    This forum makes me dizzy!

    I'm trying to pass the time until I can get a Niner carbon fork (and then the rest of the bike attached to it) by designing and building some lights, the intent being to spend a lot less than I would pay to buy them.

    Some of you guys are absolutely amazing!

    Every time I think I have my plan figured out, I read something else and get new ideas, confused, dizzy, or all of the above!

    I don't know a whole lot about the electronics, so I am trying to pick it up as I go. I thought I could use some spare parts from work as the housing, but I think it will be a bit of time and effort to attach them to one another and I might be better served buying a housing.

    So, having said all that here is what I'm considering:

    Hammond 1457C801BK watertight housing: http://www.alliedelec.com/Search/Pro...ntent=806-1565

    2 X Cree XP-E Triple R2 - $23.14 parallel, $23.62 series from Cutter
    2X Carclo 20mm Triple optics(haven't decided which angles to use) - $6.88 ea from Cutter

    Questions/comments:

    1. I'm intending for a bar mount light and a small helmet mount, does this sound good as a bar mount? I'm getting 615.6lm @ 350mA using the Cree calculator.

    2. Heatsinks - I assume fins do no good unless exposed to outside air, so maybe a small aluminum block inside the housing thermally bonded?

    3. What driver(s)? I really don't know what I'm doing here.

    4. I'd like to go with perhaps a 14.8V 18650 pack, but I'm confused as to the different options and even whether this will be right for my plan. What's the reason to not go with higher output batts, other than increased cost? (for example 2200mAh vs. 2400mAh)

    5. I'm planning for this to work for a 24 hour race, perhaps with 1 spare battery pack to swap out, does this plan seem to make sense?

    Man, I'm dizzy again. This crap is confusing! I'm hoping also to make it water resistant if not waterproof. I'm sure there's more I need to ask, but this is good for now.

  2. #2
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    I forgot a couple things:

    6. I'd like some ability to dim, such as the rotary knob I saw in one of the threads here.

    7. Series or parallel for the LEDs and batteries? I'm not really clear either way.

    Sorry for being so clueless, I am a fairly smart guy but completely new to this. I started to have a Mfg Engineer help me with it at work and his first comment was, "Why would you need heat sinks?" Then I pointed out the system I had referenced was pulling 700 mA and he was like, "Ohhhhhh, you want to light up the night, not just be seen. Let me look at this a bit more when I get some time."

    So far he hasn't had time.

    I think I have a cool reject part from work that will make a great 3X XP-E helmet mount.

  3. #3
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    I think the best thing to do is not try to make the best light possible on your first try. That saves money and frustration. Most of these lights are the same, the only thing new is better emitters and optics. Look at the older construction threads even though they don't have the same emitter.

  4. #4
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    getting all stabby...

    I'll take a stab at answering these with what I know. YMMV.
    Quote Originally Posted by cycleboy
    2X Carclo 20mm Triple optics(haven't decided which angles to use) - $6.88 ea from Cutter
    Get a few different ones. I'd go for a narrow and then the next widest up. But I'd buy two of each since you're going to wait a bit for them and they're not that expensive.
    Quote Originally Posted by cycleboy
    2. Heatsinks - I assume fins do no good unless exposed to outside air, so maybe a small aluminum block inside the housing thermally bonded?
    Get a big block of aluminum for the inside. Either use computer heatsinks or a piece of extruded aluminum on the outside.
    Quote Originally Posted by cycleboy
    3. What driver(s)? I really don't know what I'm doing here.
    Maxflex from TaskLED.
    Quote Originally Posted by cycleboy
    What's the reason to not go with higher output batts, other than increased cost? (for example 2200mAh vs. 2400mAh)
    Increased cost.
    Quote Originally Posted by cycleboy
    5. I'm planning for this to work for a 24 hour race, perhaps with 1 spare battery pack to swap out, does this plan seem to make sense?
    This says you'll bet about 3 hours per battery.
    Quote Originally Posted by cycleboy
    6. I'd like some ability to dim, such as the rotary knob I saw in one of the threads here.
    This is built into the Maxflex. You use a momentary switch to change levels.
    Slow-core. -.. .-. .. -. -.- .... --- -- . -... .-. . .--

  5. #5
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    unterhausen - you are most certainly right, I keep trying to make the best possible my first time around. The problem is, I need to avoid getting into the "always building/tinkering with something new" mode like some of the dudes in this forum are. I've got to keep my $ for the bike, plus there's always more projects we need to do around the house. Snuggling up to my next light at night just wouldn't be the same as a warm wife (if she kicks me out for spending too much on lighting!)

    But, thinking of simplifying a bit, do I really need 2 triple XPE's on the bars and 1 or 2 on the helmet? I guess the real question is what sort of total output should I be shooting for to have enough light for typical SoCal fireroad/singletrack and maybe a 24 hour race here or there?

    If I can nail down the desired output, I can then figure out how much on the bars and how much on the helmet and go from there. Like maybe 60% bars, 40% helmet?

    Again using the Cree calculator, I think I am getting that 1 triple at 700mA would give 535 lm. If I put one of those on the bars and one on the helmet, I get 1070 total lumens. Enough?

  6. #6
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    Hi Cycleboy.

    What you want and what you need are 2 different things.
    2 lights then increased cost with 2 batteries and 2 drivers .

    advantage is redundancy if one goes belly up in a 24 race .
    and easier to mend that breakdown with one on the head

    a triple on the bars would be enough . and a triple on the helmet a bonus.
    the carclo narrow for the helmet and the next widest for the bars as notaknob says would be great , I have tested in my infinate tinkering the wider ones are too wide and floody



    cheapest option is the torch route . then the converted torch .
    then you get on to making / adapting other things into a housing. .

    Really for us to suggest a light what is your budget to keep the snuggles happy.
    dont forget she wants you to come home uninjured and bad lighting is dangerous.

  7. #7
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    I think that ideal would be 2 x triple R2/Q5 or 2 x MCE on the bars with middle beam, and one triple R2 or MCE with narrow beam on helmet. Maybe one 4 x R2 on bars, and one triple R2 or 1 MCE on helmet.

  8. #8
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    I must say I don't have a specific budget, but "less than what I'd pay to buy one fully assembled". Kinda lame, I know, but I actually enjoy the tinkering and thinking about it (even with the dizziness from this forum! ).

    I may have found something perfect for this. We have a camera head at work that measures about 57mmX35mmX44mm and tapers towards the back end to about 35X32). If I remove the zoom on the front of it, it will have an aperture of around 19-20mm at the front end. The back has a pair of buttons that I may be able to wire up as on/off or some sort of dimming (normally they access on-screen menus). It is all black, champagne, or pewter anodized with the button cover blue/silver. Below the buttons, it has a threaded hole where a cable normally screws in. I can probably rig it to use the cable threaded backnut and put my own wires instead of the cable.

    The entire assembly is waterproof (it has to pass a leak test under vacuum) since it is used in surgery.

    Best part, I can probably get scrap ones for free! They might not look perfect, but free is free!

    I would have to figure out a clean way to attach a bar mount without compromising the sealing, perhaps grind off some anodize and epoxy?

  9. #9
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    Ok, I'm narrowing it down and feeling less dizzy!

    My scrap housing from work will be perfect for this. I almost could have a front window from sapphire glass, but we don't have any that are the right diameter and I don't think I want to try to grind one down. I may just cut some lexan and seal with an o-ring and silicone.

    The plan now:

    1 XPE triple R2
    Carclo 20mm triple optic
    Buckpuck 3021 or 3023
    Switchcraft panel mount connector (http://search.digikey.com/scripts/Dk...name=SC1206-ND)
    Mating SC connector on the cable
    14.8 Li-ion pack

    Ok, more noob questions now:

    1. The SC connector says it can take up to 20awg wire, is this going to be too small to carry the kind of current I'm asking of it?

    2. If 20awg wlll work, does anyone have a source for 20awg of the curly "phone cord" type? I like that kind of wiring to soak up any needed stretch as bike or head moves around.

    3. Am I on the right track with the driver now that I've gone back from 2 triples to just 1?

    4. Are there any reliable US suppliers for the LEDs and optics? It seems like not. LEDsupply doesn't list the XP-E.

    5. Series or parallel on the LEDs? I'm not really clear on an advantage/disadvantage of either in this set up. I'm thinking the batteries make sense as 4S1P?

    Once I get the details sorted, I should be about set. It is going to be pretty cool. The size and fit of the components inside should be perfect. It'll be waterproof and the housing has 2 buttons on the back that I'm hoping I can get one of our electronics guys to rig up for Off/On and Hi,Med,Low. There's a board already attached to the buttons that runs onscreen menus, I just have to see if someone can alter it for my use.

  10. #10
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    cycleboy I am sorry to have to tell you this


    But this thread is useless without pictures
    of your scrap housing .

    I for one have a vision of a medical poke it inside someone camera and having had one poked inside would like to see it as a bike light

  11. #11
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    Ok, I'll get some photos momentarily. I don't have the entire thing here at home right now (missing the back cover where the power input and buttons will be).

    You're right, it is part of one of the stick it inside you cameras! It isn't the portion that goes inside you but rather the part the doctor holds to control the stuff inside you.

    I'm pretty sure I can get the button board rigged to do what I want and if so it is going to be very sweet.

    Now I'm looking for details on the cateye mount people have been using for helmet or bars. I have to search the millions of threads I've been reading around here the last 3-5 days!

  12. #12
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    Here we go:
    This is the main housing showing the front side. EDIT - I should add the parts you see inside the silver ring will not be there for my light, those are scrap and that's where the optic will sit.

    Main housing with the front cover detached.

    Sideways view of housing

    Back of housing. The board will not be in there and there will be a press fit back cover that is sort of tent-shaped with 2 buttons on one side of the "roof" of the tent and the power input connector on the other side of the roof.
    Last edited by cycleboy; 03-22-2009 at 05:51 PM.

  13. #13
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    Quote Originally Posted by cycleboy
    Now I'm looking for details on the cateye mount people have been using for helmet or bars. I have to search the millions of threads I've been reading around here the last 3-5 days!
    I'll save you that search. Here are the CatEye parts: You want the H-31 or H-32 bracket (depending on your bar size), and the "spacer" which is the part you'll attach to your light.

    JZ
    It's not about speed, it's about lack of control.

  14. #14
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    Does anyone have the dimensions on the spacer? (or better yet, a link to a pic with them?)

    When the spacer is mounted on the light, does the light then slide in from the front? In other words, the front of the bar or helmet mount enters the back of the light?

    If so, that's exactly what I need, just need to sort out the dimensions to see if it will fit right along with everything else I'm cramming in there.

    One other cool thing about the housing is I have access to all the drawings used to make every part involved, no measuring required, just look at a drawing! For example, the front aperture on the cover is 0.9145".

  15. #15
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    Quote Originally Posted by cycleboy
    Ok, I'm narrowing it down and feeling less dizzy!


    Ok, more noob questions now:
    You plan sounds right to me. The XPE is not, as far as I know, available in the USA premounted on a triple 20mm board. Digikey has them as unmounted emitters, but i think you'd need a stereo microscope and a very steady hand to mount and solder them yourself! So Cutter is your only option right now. Series wired, with the 14.8v battery, and a buck driver, is good.

    The 3023 buckpuck is pre-wired, which makes life easier for us noobs. And it's nearly idiot-proof (unless you get the battery polarity wrong) which is why I like them. It's almost 7/8" square and a half inch thick....do you have room for it?

    Not sure what is the correct wire gauge to use, between battery and driver or driver to leds. But I'm using 22g on my 2 x XRE light and it's working well.

    JZ
    It's not about speed, it's about lack of control.

  16. #16
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    Quote Originally Posted by cycleboy
    Does anyone have the dimensions on the spacer? (or better yet, a link to a pic with them?)
    When the spacer is mounted on the light, does the light then slide in from the front? In other words, the front of the bar or helmet mount enters the back of the light?
    Not sure....I just ordered some. You might try searching for the "Achesalot" or "Easy DIY" threads....I think there were some photos with this mount.

    JZ
    It's not about speed, it's about lack of control.

  17. #17
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    I should have room for the driver in there. The inside of the housing towards the back is 36.8X33mm, so I think if I attach the driver near the back on-edge, it should fit just fine. This will also be a good spot considering where the wires will need to go. I have to ask my electronics guy if I need the driver w/ a pot on it or not. I'm thinking our board may be able to take care of it. Do I need the driver attached to heatsink too, or is that more a thing w/ a boost driver?

    I'm going to see if the heat sink adhesive and grease we have at work will function for attaching the PCBs and the heatsink/mount. My plan is to attach the PCBs to the mount and the mount to the front piece, but then just have grease between the mount and the bottom of the housing. A couple screws to hold the Cateye spacer on will also go into the PCB mount and keep it in good contact with the grease. This way the whole thing will be removable if need be instead of permanently stuck together.

    I saw some photos of the Cateye spacer, just wish I could find the dimensions of at least its footprint so I can get an idea of how it will fit on the bottom.

  18. #18
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    Sounds like it all should work. The Buckpuck drivers do not need to be heatsunk. You shouldn't need the version with the pot if you're going to control it with the switches. Just get the dimmable version without the pot. This thread talks about what resistance values will give you what amperage.

    Don't know how soon they'll be here (ordered earlier today) but I'll post some dimensions on the cateye parts when I get them.

    Looking forward to seeing your light come together! Sounds like an almost perfect ready-made triple xpe housing.

    JZ
    It's not about speed, it's about lack of control.

  19. #19
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    Another driver question - the XPEs can go up to 700mA if I'm reading everything correctly.

    So, do I want the 700mA Buckpuck or the 1000mA and just don't run it higher than 700?

    Hoping to nail down final details and order some parts today.

  20. #20
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    This may be getting better and better. I don't have an answer yet on whether I can make our button board do what I want, but I have a backup plan if not (I can use a back cover with no button holes and put my own hi, off, lo switch in stead).

    But, I just found a set of parts we're going to scrap out that are all champagne anodized, so I could have the whole thing in matching colors!

    Not only that, but I think I figured a way to get rid of the front cover (the piece in my second pic above) and just use the fron of the housing as is. That would cut a decent bit of weight out of the thing.

  21. #21
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    Get the 700mA buckpuck. The resistance values I linked to may need to be adjusted slightly....I think those numbers were based on the 1000mA model?

    A while ago someone mentioned using a micro pot instead of fixed value resistors...allowing you to easily tweak your brightness levels. Multi-turn pots would give you more accuracy, but this type will work and are smaller.

    JZ
    It's not about speed, it's about lack of control.

  22. #22
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    Well, I just jumped in and ordered a bunch of stuff. I'm going to make 3 to start with.

    I've got plenty of parts to practice with while I wait for other stuff to arrive.

    Cutter freaked me out with the prices until I realized they are in Aus. $. I didn't like some of the options on the products (why do I have to pick the LED type twice and show a charge for each? Had to pick R2 under the single LED drop down and then R2 again under the triple.) I forgot to order AAA from them, so I emailed them. Any idea if they can change orders after the fact or how easy to deal with such a situation is?

    I figure all told these will run $160 including tax and shipping and about half that is the battery packs and chargers
    Last edited by cycleboy; 03-24-2009 at 05:19 AM.

  23. #23
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    If you haven't committed to buying the AAA from Cutter already, you might want to look at bestbyte.com or sidewindercomputers.com......considerably cheaper. I think when I bought mine from Sidewinder it was ~$12.50 for 2 packs, shipping included.

    JZ
    It's not about speed, it's about lack of control.

  24. #24
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    I've emailed cutter tiwce, but they haven't responded yet. All of my other stuff has shipped and batteries will be here Thursday. I ordered them last night and got an email last night with a tracking #. As long as they actually shipped today, that's damned fast (batteryspace).

  25. #25
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    Got my drivers today and test fitted them in the housing:

    Shows the new back cover, housing (w/ driver), and front cover.

    Closer shot of the pieces. The front and back cover are press fit w/ o-ring and silicone RTV sealing. There will be a clear window cemented into the large hole in the front cover and the LED optics will be behind the window.

    Back view of the housing. The gold area is the press fit for the back cover. The small tab behind the driver can potentially be removed in order to make the LED mount bigger and thus pull out more heat.

    I'm really happy with it so far and even more so that my scrap parts are all color matched now. It looks really cool. I will put the LED board on a U shaped mount that will go in front of the driver and be cemented w/ AAA to the housing. The front cover will be a separate piece so I can remove it and change optics if needed.

    EDIT - 2 emails to Cutter and still no response. No idea if they added the AAA to my order or have done anything w/ shipping yet.

  26. #26
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    Quote Originally Posted by cycleboy
    Does anyone have the dimensions on the spacer? (or better yet, a link to a pic with them?)

    When the spacer is mounted on the light, does the light then slide in from the front? In other words, the front of the bar or helmet mount enters the back of the light?
    CB - My Cateye mounts arrived today. the "spacer" is 15/16" wide and 1 3/8" long. You can set it up so the light head slides on from the front or the rear, depending on how you orient the bracket and spacer. Something I wasn't aware of: there is some left-right pivot adjustment built into the bracket, which is locked in place when you close the cam clamp. It's a pretty nice unit for $4.75.

    The spacer has a spring-loaded clip that locks it to the bracket. The spring is tiny and easily lost....only a problem when you are messing around with it unmounted. Once the spacer is screwed to your light, the spring is contained.

    The mounting surface of the spacer is perfectly flat, so it may not work as well with round light housings as it will with flat-bottomed housings like Hammond cases or Achesalot/Amoeba style square tube lights.

    That is a lot of words to say "I like it"

    JZ
    It's not about speed, it's about lack of control.

  27. #27
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    The size sounds pretty good. I'm out of town this week, so I will have to verify when I get back on the weekend. I did get a message from Cutter that they shipped my stuff, but no idea if they added the AAA or not. Guess I wait til it arrives and see. . .

  28. #28
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    I started a bit of prototype fabrication today with the glass grinder. I need to cut the top and bottom edges of my front glass down from 38.1mm to around 33-34mm to fit inside the front cover. The test part came out ok (edges aren't nicely ground and beveled, but oh well) and I will have my better half glue it to the front cover tomorrow. I have to ask one of our engineers if I'll be better with a true adhesive or just silicone. I may have to go with silicone because the back of the front cover is not completely flat and the sapphire window most definitely is. The adhesive may not fill the gaps as well.

    I have enough front windows though to play around and thrash several and still have good parts to use.

    I have nearly everything now, just need the stuff from Cutter, AAA (if it isn't in the order), a switch, and some 1/16" Al to fab into the LED mounting plate.

    Getting exciting!

  29. #29
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    Quote Originally Posted by cycleboy
    some 1/16" Al to fab into the LED mounting plate.
    If this is the piece that's conducting the heat from the leds to the case, I'd go thicker.

    JZ
    It's not about speed, it's about lack of control.

  30. #30
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    Quote Originally Posted by cycleboy
    Got my drivers today and test fitted them in the housing:

    Shows the new back cover, housing (w/ driver), and front cover.

    Closer shot of the pieces. The front and back cover are press fit w/ o-ring and silicone RTV sealing. There will be a clear window cemented into the large hole in the front cover and the LED optics will be behind the window.

    Back view of the housing. The gold area is the press fit for the back cover. The small tab behind the driver can potentially be removed in order to make the LED mount bigger and thus pull out more heat.

    I'm really happy with it so far and even more so that my scrap parts are all color matched now. It looks really cool. I will put the LED board on a U shaped mount that will go in front of the driver and be cemented w/ AAA to the housing. The front cover will be a separate piece so I can remove it and change optics if needed.

    EDIT - 2 emails to Cutter and still no response. No idea if they added the AAA to my order or have done anything w/ shipping yet.
    Sorry but can you advise what your order ID was, I dont have any outstanding emails at the moment?
    Cheers
    WeLight

    Cutter Electronics Pty Ltd www.cutter.com.au

  31. #31
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    Order was shipped on the 24th of March and included the Arctic Silver, we must have responded for you to pay the extra to cover it??
    Cheers
    WeLight

    Cutter Electronics Pty Ltd www.cutter.com.au

  32. #32
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    Hi, I got an email that it shipped on 3/30, but never anything saying the AAA was added. The order ID is 7085. I'm glad you were able to add it in there so I don't have to keep shopping, just didn't know it got added.

  33. #33
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    Quote Originally Posted by JimZinVT
    If this is the piece that's conducting the heat from the leds to the case, I'd go thicker.

    JZ
    It is and it isn't. My mount part will look like a "+" that I will then fold the 4 legs up so I have a sort of little box. The LED board will go on the front of the box with the 4 legs pointing backwards and each one attached to the inside of the housing.

    So, I need to find the right combination of bendable enough to do this origami and enough material for good heat sinking. I'm thinking 1/16" so I can form it easily and then attach a plate to the inside of the box (other side of the surface the LED mounts to) to help with heat sinking. I'm not sure I can bend 1/8" plate up how I want it.

  34. #34
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    I've re-thunk the LED mount/heatsink part and I may be able to make it from 1.25 X 1.25 X 0.125 angle iron. I will then only have to bend 2 of the wings back, which may be possible. If not, I can probably just omit those 2 wings and just attach the angle to top or bottom of the housing and not the sides. I just liked that idea for the more solid mounting and better contact with the outer housing.

    With this plan I add some weight, but get the extra 1/16" of thickness to pull heat out.

  35. #35
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    Quote Originally Posted by JimZinVT
    Sounds like it all should work. The Buckpuck drivers do not need to be heatsunk. You shouldn't need the version with the pot if you're going to control it with the switches. Just get the dimmable version without the pot. This thread talks about what resistance values will give you what amperage.

    JZ
    Now that I am close to actually wiring things, I looked over the thread linked above and I think I like the layout diagrammed by mtnpat w/ a 3 position switch giving Hi, Lo, Off.

    As I understand it, I could either wire in a fixed value resistor for the Lo setting or a pot that I could then adjust to the desired brightness for that switch position?

    Which is easier? How can I figure out the resistor value to use if I wanted say 350mA as the Lo setting (as you mentioned the figures in the thread are for the BP 1000 and not the 700 that I have)?

    If I did use a resistor, what's the right way to solder it inline w/ the stranded wiring?

    Thanks again for all the help.

  36. #36
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    I like the micro-pot idea, because you can see what your low setting will look like and set it exactly how you want it. A bit more expensive of course.

    Solder one leg of your resistor (or micro-pot) to the switch and the other to the wire.

    JZ
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  37. #37
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    I may have found a super tiny micro pot (3mm square) in my scrap bin.

    http://www.bourns.com/data/global/pdfs/3313.pdf EDIT - I have the 5K model.

    Does anyone know if this will work and give me the right range for my dimming plans? (basically I need to adjust it to get 50% current or so).

    I'm not sure how I connect up the 3 contacts to make the circuit work though.

    EDIT - Ok, I think I have figured out these pots won't work. They are rated for 0.125 watts and I'm running what, 0.7A X 14.8V = 10.6 watts? Did I do the math right?
    Last edited by cycleboy; 04-09-2009 at 09:51 PM.

  38. #38
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    I think I was being an idiot last night, or the beer was talking!

    I'm now of the mind that the 0.125W listed for the pots is how much power they suck up, not how much they can handle. If I'm right, they should work.

    Anyone know?

  39. #39
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    The rating is their capacity. If you are using it to adjust the output of the buckpuck, it will be fine. The buckpuck datasheet says that the ctrl current is 5mA. If you use the 5v internal ref voltage this equals .025W, far under your pots .125 rating.

  40. #40
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    Yes, I believe that's what I am doing. My wiring will look like post #16 from this thread:

    http://forums.mtbr.com/showthread.ph...24#post4089324

    Except I will put the micropot in place of the fixed resistor, adjust it to get visually my desired low setting for the light, then seal it up inside the housing, never to be touched again.

    Make sense?

    It's funny, I flip flop on this project from feeling like I totally know what I am doing to feeling like I am a clueless boob. I'm right in the middle at the moment on this micropot topic!

  41. #41
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    It will work. A little more robust setup would be to use the pot to find what resistance gives you the low beam you want. Then measure the pot at that setting and replace it with a fixed resistor of the same value.

  42. #42
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    Well, if it is a choice of robustness, maybe I'll just try a few fixed resistors until I find what I like, then solder it in?

    In other news, FABRICATION HAS BEGUN!!!! Totally exciting!

    This is the LED mount piece - 1/8" Al angle cut down to fit inside the housing. The short side will attach to the top of the housing w/ AAA.

    Prototype back cover w/ switch and power connector, housing w/ driver installed, and LED mount with PCB glued on.

    Inside of first prototype back cover. A lot of dremel work was done to get the power connector to sit flush. The second one will be a lot cleaner now that I know what I am doing. Good thing I've got a few extra parts to experiment with!

    If all goes well, I may have something done by the end of the weekend!

  43. #43
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    Let There Be Light!

    And there is, and it was damn bright!

    Almost complete, just need to find the proper resistor to give me ~50% output, solder it into place, press the back cover on, and attach the mounting spacer.

    Best thing, I charged up a pack, plugged it all in, and it worked perfectly!! Left it on for a minute or 2 and didn't feel much heat. We'll see once I leave it on longer. I didn't want to without the back cover on because there's an unattached wire right now and nervous it would short to something.

    Front view where you can see the 20mm narrow optics through the front window. This one will be for the helmet.

    Side view showing that the back cover is attached but not pressed in yet. Because I'm using scrap housing parts, I even have a serial number!

    Back view with power input and 3 position center-off switch.

  44. #44
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    Cool light! What was the housing originally for? It looks really cool and you could probably cram even more LED's in there - I'm thinking that an 8x XPE could be possible with it, using the 10mm square optics. With that case you should have quite a few driver options if you are going to build another one.

  45. #45
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    The case was originally for a 3-chip video camera for microscopy. I was planning to use scrapped out used ones, then we ended up scrapping some very old but new ones, so that's what I wound up with, complete with a cool laser marking on the top.

    I could possibly fit more in the front, but the fabrication of the heat sink/LED mount gets a little complicated with my lack of real machining tools. EDIT - In addition to the L-shaped mount in the pics above (which is glued to the top surface of the housing), I also cut 2 smaller L pieces that are stuck to the back of the LED mount and adhered to the sides of the housing. So I have thermal contact w/ top and sides and all 3 L pieces are 1/8" Al. If I wanted to put more in the front end, I would need the LED mount to be wider at the front and then taper towards the back since that's the shape of the housing. That gets tricky to make w/ a hacksaw and files!

    I didn't get too many pics during the actual construction, but I'm going to be making at least 2 more of these (1 for my bars and 1 for a friend's bars), so I will get more shots of them.

    Oh, and I know I need some beamshots, those should happen tonight.

  46. #46
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    Quote Originally Posted by Vancbiker
    It will work. A little more robust setup would be to use the pot to find what resistance gives you the low beam you want. Then measure the pot at that setting and replace it with a fixed resistor of the same value.
    Ok, I tried this and found a setting that seems like "half" output.

    I want to validate it mathematically and then I won't have to try a lot of different resistors to get what I want.

    I can't get it to work out using Ohm's Law and I'm sure it is because I'm missing things in my calculations.

    I measured the resistance of the pot using my multimeter at 0.93 kOhms at the setting I chose. How do I validate that this is sending ~ half the current through to the LEDs? Is it also logical that half the current should = half the light?

  47. #47
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    Quote Originally Posted by cycleboy
    Ok, I tried this and found a setting that seems like "half" output.

    I want to validate it mathematically and then I won't have to try a lot of different resistors to get what I want.

    I can't get it to work out using Ohm's Law and I'm sure it is because I'm missing things in my calculations.

    I measured the resistance of the pot using my multimeter at 0.93 kOhms at the setting I chose. How do I validate that this is sending ~ half the current through to the LEDs? Is it also logical that half the current should = half the light?
    You can measure current if your multimeter has an amps capability of 1 amp or more. Set the meter to amps (you will have to reposition the positive lead on most meters) and connect in series with the LED. Then turn on the lamp, you'll directly read the current being drawn. Current and output are not proportional to each other. Look at the datasheet for your LEDs and there is usually a chart that shows output relative to current.

  48. #48
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    Is it also logical that half the current should = half the light?
    No life is never that simple.

    LED's are far more efficient when run at lower currents for example if 1000ma is full(brightest) then 500ma may only be a third dimmer and it could be that as low as 400ma could produce half the light output. this is due to less heat at the lower currents so more light is produced.

    As Vancbiker says you'll find a chart for most of the LED's in common use.

  49. #49
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    From fig 16 on the datasheet:
    http://www.leddynamics.com/LuxDrive/...1-BuckPuck.pdf
    %Iout = R1/50
    2.5K will give 50%

    You've got 1K so 20%


    Personally I'd put a pot in it and go for a ride. Try different dim settings until you find one you're happy with, then replace with a resistor.

    Actually I'd put the on/off switch inline with the battery and use a 3 throw switch on the light to give low/med/high for climbing/flats/descending... much more useful.

    Chart of input current/power/lumens here:
    http://www.candlepowerforums.com/vb/...&postcount=158

  50. #50
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    Thanks for all the info guys! I'm sort of stuck to my plan to wire it as is and either put a pot in and adjust it to visually get what I want or find the right resistor and put it in. The problem is everything is soldered and shrink wrapped now and once I press the back cover in, it is really intended to not be pulled apart again. The front cover where the LEDs are is a light press fit w/ silicone and the back cover where the resistor or pot will go is a full press fit, o-ring seal, and silicone.

    Bottom line, I'm hoping to dial in a low setting that makes sense, solder on a resistor, and press it all together, never to be pulled apart.

    Beamshot of the helmet version w/ the narrow optic:

    f4.5, 6 seconds, the grape post is ~20 ft away and the fence is ~45 ft away. No can do manual focus, my eyes don't work that well even w/ glasses!

  51. #51
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    Thanks for the info on the housing, after reading it I recalled that I had read about it earlier in the thread weeks ago, but missed it when I re-read it recently.

    That is a nice looking beam, I think it looks very good for a helmet light. Brightness looks pretty good too, is that on high?

    Your method of setting the output level is really the only one that makes sense since the final result must be usable for you. Also the buckpuck does not cooperate when measuring the actual current though the LEDs using the usual method (a different method is described in the datasheet). What I did was just measured the voltage going to the control pin on the buckpuck and compared that to the graph that figure 2 on the datasheet (output current vs control pin voltage) which gave an approximation of the current to the LEDs, more informational since I had to see what each setting looked like and adjusted from there as well.

  52. #52
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    Yep, that's on high because right now there is no low until I get that resistor on there.

    I'm happy w/ it and I have the 2nd (bar mount) fairly far along already. It should be up and running by next weekend.

  53. #53
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    Ok, yet another question I can't quite get answered in my head:

    What wattage resistor(s) do I need? I talked to an electrical guy at work and he said if needed, I could put more than 1 resistor in there, but I'd rather not since space is tight if I can just find 1 that can handle the power it will see and give me the right resistance value to drop the light output to what I want.

  54. #54
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    You don't need a 1 watt resistor, the small (and common) 1/4 watt will work. The current on the control pin is only 20mA (at 5V).

    If you need to get a value that you don't have, you can use a calculator like the one here to figure out a mix of parallel or series resistors.

  55. #55
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    The first one is 99% done! Hi-Low works great. I wound up with an 800 Ohm resistor and just visually decided that was a good setting. I actually used the pot to adjust it, then measured the pot and found a resistor that was close. I'll take a Low beamshot when I get a chance.

    All that's left on this one is to find the right adhesive to stick the Cateye spacer onto the housing, then mount it up.

    #'s 2 and 3 are started and most of the metal fab is done. I think both of them will be done next weekend. Both of them will be bar mount and I did that version second because I haven't yet found a way to mount the battery pack that I like. I'm thinking under the stem pouch, just have to find something weather resistant, right size, etc.

    Here's some more photos:

    Completed light side view. Ruler was for size, but the reflection didn't make it show up well.

    Front view showing the optics and the size relative to my hand.

    Rear view w/ 3 way switch and power input connector.

  56. #56
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    Very nice salvage work. Those are some great looking casings, looks most professional and should be relatively easy to upgrade in the future or swap lens. Keep up the good work.

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    That's probably the part I'm the most excited about. I took really nice pieces we were going to melt down and turned them into cool little lights. I even like how the laser marked logo looks. It was for something else, but looks like it was meant to be there.

    I weighed it all this morning:

    Light module = 100.5g
    Battery pack = 194.5g
    Cable = 35.5g
    Helmet mount = 23g

    I'll see what the difference is w/ the bar mount once I get one done. It'll have less cable and a different mount, so maybe around the same total weight.

  58. #58
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    I ran a heat test tonight:

    On high for 20 minutes on the kitchen counter and held in the hands every minute or so.

    After around 15, it didn't seem to get any hotter. It never got more than what I would consider warm to the touch. I wanted to try it with something that actually reads degrees, but couldn't find anything. I'm assuming after 20 minutes if it is not more than warm to the touch, I'm in decent shape as far as heat, especially once I have air moving over the outside.

    Does anyone know what kind of heat ramp up is typical? If they aren't really getting hotter after 20 minutes, are they likely to get any hotter?

  59. #59
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    Nice work!

    JZ
    It's not about speed, it's about lack of control.

  60. #60
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    Quote Originally Posted by cycleboy
    I ran a heat test tonight:

    After around 15, it didn't seem to get any hotter. It never got more than what I would consider warm to the touch.

    Does anyone know what kind of heat ramp up is typical? If they aren't really getting hotter after 20 minutes, are they likely to get any hotter?
    you don't have a huge slab of aluminum in there soaking up heat, so it's certainly reaching equilibrium in that time. With air flow it should be cool

    JZ
    It's not about speed, it's about lack of control.

  61. #61
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    I got some "industrial strength" velcro at the Depot today to mount the Cateye spacer to the light. I tried it tonight and I don't think I'm happy.

    It was a bit wiggly once stuck to the spacer and light housing. I think the adhesive is sticky enough, but is a bit thick, so it is wiggly.

    Also, once the velcro was velcro-ed to itself, I noticed the light wiggled a bit w/ the spacer. If I shook it enough, it actually got loose. Would it be enough to be a problem on my helmet or bars, I don't know. It's right now a concern and I will take this one on a ride before I decide whether to use the same method on the next lights.

    I definitely like the ability to change the spacer if I should have a reason to go with a different mounting system in the future. I'm just not sure if velcro is the ideal way to get that ability.

  62. #62
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    I have not tried velcro as a mount, but that is what Scar uses on his Amoeba lights and everyone seems to say it works well. His may be a bit smaller/lighter than yours though?

    Could you just fasten the cateye spacer to yours with a screw into a tapped hole, or a bolt through the case?

    JZ
    It's not about speed, it's about lack of control.

  63. #63
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    I could, but I would like to not put any holes in it if I can avoid it. The whole thing is sealed by design for its original use and I've only added the switch and power connector that I sealed with o-ring and silicone, so I'd prefer to not add more holes.

    I guess I have to decide if permanently attaching the spacer w/ JB Weld or another epoxy is a better tradeoff than putting a hole through the housing. I don't need the ability to change it, was just thinking someday Cateye might change their parts or I might find a mount that works better.

    Oh yeah, Scar is where i got the velcro idea from. I think maybe it isn't so much the weight as it is that mine is sort of narrow and tall with weight up higher and the Amoeba is low and wide. Mine's got less contact area w/ the velcro and more of a lever arm to pull on the sticky stuff.

    Scar also gave me the idea to dip batteries in tool coat, which I will be doing this weekend. That way the bag they go in doesn't need to be waterproof.
    Last edited by cycleboy; 04-17-2009 at 04:49 PM.

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