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Triple Cree light waterproofing - achesalot can you help me here

3K views 33 replies 13 participants last post by  dmcalpin 
#1 ·
Hey achesalot,

I just built your triple cree light and am very happy with it!

Just one question for you (or anyone else who has built the light) how did you make it waterproof/resistant at the front? I'm thinking about recessing the two middle sections on the front 2mm and gluing a glass panel in there...

Everyone's suggestions welcome
 
#2 ·
wilso_ac said:
Hey achesalot,

I just built your triple cree light and am very happy with it!

Just one question for you (or anyone else who has built the light) how did you make it waterproof/resistant at the front? I'm thinking about recessing the two middle sections on the front 2mm and gluing a glass panel in there...

Everyone's suggestions welcome
I'm running the square LEDIL lenses which fit tight in the 1" square alu tubing, that doesnt need any additional waterproofing. However, where the main body joins the front piece with the lenses, I waterproofed that by applying some electrical tape over the joints.



The only futher possible leakage point are the holes in the main housing where the powerwires for the LEDs run trough, I sealed those by applying some silicone sealant on the inside. Actually, almost the entire inside of the light is filled with the sealant.
 
#3 ·
wilso_ac said:
Hey achesalot,

I just built your triple cree light and am very happy with it!

Just one question for you (or anyone else who has built the light) how did you make it waterproof/resistant at the front? I'm thinking about recessing the two middle sections on the front 2mm and gluing a glass panel in there...

Everyone's suggestions welcome
If you have the light round, you can use ruber o-rings, how my light, look, those are water proof







Greetings - Saludos

msxtr
 
#4 ·
Is there really any need to make sure that lights are waterproof?

I have a very rough DIY halogen running at 14.4V. The connectors and casing are not even vaguely water resistant, so I was worried about getting them wet. The other week I tried fully immersing the bulb casing and all the wiring, and everything still ran fine underwater.

So from a safety point of view, waterproofing doesn't seem such a big deal. I can understand that one might need to protect the electronics from oxidisation though.

PS: Hi Brum, I didn't realise you're also on MTBR. I'm taking part in your CPF Ledil GB and will try an a DIY LED soon.
 
#5 ·
brum said:
I'm running the square LEDIL lenses which fit tight in the 1" square alu tubing, that doesnt need any additional waterproofing. However, where the main body joins the front piece with the lenses, I waterproofed that by applying some electrical tape over the joints.

The only futher possible leakage point are the holes in the main housing where the powerwires for the LEDs run trough, I sealed those by applying some silicone sealant on the inside. Actually, almost the entire inside of the light is filled with the sealant.
Hey Brum,

What type of power connectors are those? I've been checking out some various battery options on batterspace and I still haven't settled on one yet. They have packaged NiMH and Li-Ion deals that come with smart charger and connectors. I was curious if yours is something like that, or something different. Do you have any pics of the connection in the back?

Thanks,
Lev
 
#6 ·
Lev said:
Hey Brum,

What type of power connectors are those? I've been checking out some various battery options on batterspace and I still haven't settled on one yet. They have packaged NiMH and Li-Ion deals that come with smart charger and connectors. I was curious if yours is something like that, or something different. Do you have any pics of the connection in the back?

Thanks,
Lev
They are Hirschmann 4p DIN screw-in (MAS-3100) connectors. They make a really solid connection. However, I ditched them on my V2.0 of the helmetlight.
The main reason for that is the added weight, simplicity and that its not really necessary to be able to remove the light on its own. I'm currently using only a rubber chassis-piece (how do you call it...), which is alot lighter and should also be more waterproof.





 
#8 ·
What you need to worry about shorting out is any electronics. However if you're using a buckpuck that itself is sealed, so not a problem. If you're using a different driver (bFlex etc. which would be my preference), then the best thing to do would be to pot the electronics.

Definitely no problem with shorting the power connections in lights like this - I use totally non-waterproof Amphenol connectors, and don't have any problems.
 
#9 ·
Sorry dusthuffer, but 9 to 12 volts at around an amp is not "too low to short out", and in fact as long as there is a potential difference (voltage) a short circuit is likely if enough water enters the housing. Without being submersed it is actually quite unlikely enough water could enter the housing to cause a short, but it's not just shorting that's a concern.

Although documentation is scarce and most emitters are quite resilient, most emitters are affected by excessive moisture levels in one way or another. As an example, when Lumileds Luxeon range of emitters are subjected to high levels of moisture they can be affected in a number of ways, and are far more likely to fail or suffer from lumen output degradation or significant shifts in tint.

It is documented that in certain operating environments high moisture levels can help contribute to an increase in the possibility of thermal overstress failures, and lens yellowing which leads to lumen loss through light absorption is a possibility if subjected to high moisture levels over a long period of time.
 
#10 ·
Just be careful when you recommend “potting” of drivers.

Some of Georges drivers, and I’m sure many other various drivers available on the market, do not like being potted! Even the slightest resistance or capacitance introduced by potting can have a huge effect on sensitive components. I remember there were a number of documented cases a while back where drivers failed to operate correctly as a direct result of potting.

It’s well worth reading the datasheets or asking the manufacturer if potting is okay before destroying a driver! ;)

Dave.
 
#11 ·
wilso_ac said:
Hey achesalot,

I just built your triple cree light and am very happy with it!

Just one question for you (or anyone else who has built the light) how did you make it waterproof/resistant at the front? I'm thinking about recessing the two middle sections on the front 2mm and gluing a glass panel in there...

Everyone's suggestions welcome
Glad to hear you are happy with the light.
Yes, recess the middle sections enough to fit a clear panel inside, or you can just glue it across the front (less attractive). I've done both. I usually cut a piece of 1/16" acrylic sheet to fit over the front and use clear silicone caulk to seal the edges and hold it in place. I found that applying a thin layer of the silicone caulk to some of the other joints and letting it dry before shoving the light together also works well to form a silicone gasket (but it makes the light harder to get together/take apart). Use window cleaner (ammonia/water solution) to clean the silicone caulk from the plexiglass and light body. Do not use alcohol.

In fact, you can just use your finger to rub the silicone caulk into any cracks, like tile grout, then clean the surface with window cleaner before it dries. I don't really consider my connectors waterproof, but they have survived a few light sprinkle rains with no problems.

Lots of good suggestions here.
 
#13 ·
Low_Rider said:
Sorry dusthuffer, but 9 to 12 volts at around an amp is not "too low to short out", and in fact as long as there is a potential difference (voltage) a short circuit is likely if enough water enters the housing. Without being submersed it is actually quite unlikely enough water could enter the housing to cause a short, but it's not just shorting that's a concern.

Although documentation is scarce and most emitters are quite resilient, most emitters are affected by excessive moisture levels in one way or another. As an example, when Lumileds Luxeon range of emitters are subjected to high levels of moisture they can be affected in a number of ways, and are far more likely to fail or suffer from lumen output degradation or significant shifts in tint.

It is documented that in certain operating environments high moisture levels can help contribute to an increase in the possibility of thermal overstress failures, and lens yellowing which leads to lumen loss through light absorption is a possibility if subjected to high moisture levels over a long period of time.
Sigh ... Yes, you are totally correct it is possible to short out your night light if you tried really, really hard.
 
#16 ·
Yup, I will when its finished.

It looks exactly like your version except I have put three 1" x 1" heatsinks on the top to assist with cooling. I rode to work with it this morning and was impressed by the light output (handle bar mounted) although i think I may have the wrong lenses because I would prefer it to be a bit more beamy - I currently have 2 x 9 deg and 1 x 8 deg lenses Ledil optics.

I used to ride with a 6v halogen system which had a definite spot, the Cree light seems to throw light everywhere - as attested by the pedestrians I passed this morning covering their eyes - so I assume I'm 'wasting' light because the beams are wide. the thing is damn bright though!!

I'm also making a battery in a bottle so I will post some pics when its all finished.

Just a side note - I'm driving these things at 1amp (1000mA Buckpuck) with a 14.4 v battery, when hooked up to a 14.4v power supply its only drawing 771mA full blast. I emailed Cutter this morning and will let you know what their response is. My guess is its an incorrect pot.
 
#18 ·
I'm measuring it in series on the 'battery' side of the driver. If the output is supposed to be 1amp for the LEDs the overall consumption should be higher because the driver will not be 100% efficient, so I expect 1amp outputs to the LED a small amount of current to run the driver so somewhere in the 1050mA 1100mA range?
 
#19 ·
Remember the total forward voltage of the emitters will be a lot less then 14 volts, and will probably be around 9 -11 volts assuming that you’re running a triple emitter setup, depending on the bin that you’re using. As a result, with the battery at full charge the total current draw at the battery pack should be substantially lower then 1000mA. As the battery pack voltage drops you will see the current draw gradually rise.

The job of the buckpuck is to provide a constant 1000mA to the emitters, regardless of their forward voltage, and regardless of the battery pack voltage (as long as it is a volt or so higher then the emitters forward voltage, and the voltages are within specification as stated on the data sheet).

To demonstrate, if your power supply is adjustable adjust the input voltage down by a volt or two and you should see the current draw rise. Now measure the current draw between the buckpuck and the emitters, and it should be pretty close to 1000mA no matter what the input voltage is, as long as it is a little over the emitters forward voltage.

I’d say your buckpuck is probably working perfectly fine. :thumbsup:

Dave.
 
#20 ·
Duh, yes of course, you are correct. I didn't even think about the forward voltage on the emitters not adding up to 14.4V ! I did think about this when I made the battery, just not now :madman:

As far as the power goes 771mA at 14.4v is about 11W (or 3.7W per emitter) that sounds about right.
 
#21 ·
I’ve made plenty of silly, and expensive mistakes in the past… ;)

Most common buck regulator designs are somewhere between 80%-90% efficient, although this is usually measured with the emitter forward voltage and power supply voltage as close as possible without the regulator dropping out of regulation.

I have seen some higher frequency switchers getting close to 95% efficiency, but to my knowledge they are not suitable for higher loads, or high power draw. It’s been a while since I’ve investigated this though! :D

Cheers, Dave.
 
#22 ·
wilso_ac said:
Duh, yes of course, you are correct. I didn't even think about the forward voltage on the emitters not adding up to 14.4V ! I did think about this when I made the battery, just not now :madman:

As far as the power goes 771mA at 14.4v is about 11W (or 3.7W per emitter) that sounds about right.
Dave is the man, he will straighten you out :)

That is about what mine draws from the 14.4v battery also. When I was running the Crees at 750ma, the battery draw was only about 0.55A. You can definitely get some battery life out of a 4A Li-Ion!

I used a 4 degree spot and 2 x 9 degrees on my light. It's about right for the trail, if not perhaps too spotty for me. It seems road riders like more throw, where riders on a tight, twisty trail would prefer a more even fill, with moderate throw. Maybe I should trade you my 4 degree for your 8 degree :)
 
#23 ·
achesalot said:
Dave is the man, he will straighten you out :)

That is about what mine draws from the 14.4v battery also. When I was running the Crees at 750ma, the battery draw was only about 0.55A. You can definitely get some battery life out of a 4A Li-Ion!

I used a 4 degree spot and 2 x 9 degrees on my light. It's about right for the trail, if not perhaps too spotty for me. It seems road riders like more throw, where riders on a tight, twisty trail would prefer a more even fill, with moderate throw. Maybe I should trade you my 4 degree for your 8 degree :)
I'm In Australia, so I reckon the postage for both of us would be more than just buying one from Cutter! ;) Great Idea though....

I might buy a couple of new lenses to try out the various throws....I guess thats the great thing about DIY you get to make EXACTLY what you want not something that appeals to most people.
 
#24 ·
From the specs, and also from my testing, the Fatman boost driver I use is more than 90% efficient with a 2 cell LiIon pack (6V-8.4V) driving 3 XR-Es (Vf ~10V) - at some points it's nearer 95%! That's with relatively close Vin and Vout (always a sensible thing to try and arrange that), but it's also a boost driver, which is supposed to be less efficient than a buck!
 
#25 ·
The higher efficiency switchers I made reference to were actually boost regulators, I neglected to mention that in my original post. :p

As you mention I always thought that buck regulators were generally more efficient, but recently I have seen reference to a number of boost regulators with some pretty nice numbers. Many that I have seen are reasonably restricted in terms of wattage though unfortunately.

It’s great to see those numbers out of the Fatman, what drive current are you drawing? :cool:
 
#26 ·
I've also made a triple XR-E Cree(P4) in the last month with most parts coming from www.Cutters.com.au Also ordered a triple Cree(Q2) today as they are now in stock at Cutters.

It's very basic and easy to make using
- an aluminium box from www.Jaycar.com.au as the body (search for aluminium box)
- Khatod triple lens
- 1000ma BuckPack
- cut a clear CD jewel case to cover the front of the box rather than the normal box top and hold the lens against the triple PCB and the back of the box (shaved the lens legs down till they fir exactly)

For a battery pack I use 2 by 6 AA battery holders joined together using 2500mah AA batteries which gives over 14.4v.. It seems very bright but not sure if the el-cheapo battery setup is supplying enough current under the 1000ma load and I know very little about electronics.

My question is how do I tell if the system is geting enough current/power. If I put a multimeter on the battery is shows around 15v. When I put the multimeter on either side of the triple PCB is shows around 10.2v. It runs for over 2 hrs and still seems pretty bright (still brighter than my 15w Nightrpo halogen).

Do I need a better battery setup eg a 14.8v li-ion ? What is the terminal resistance people talk about in home made battery pack ? Help would be appreciated.

Cheers
Dave
 
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