# DIY Triple LED ABS Bike Light



## tomquas (Oct 27, 2007)

Here is my design for a DIY triple LED bike light. This light is an updated LED version of an over-volted Halogen light I have been using for 2+ years. I like using 1-1/2" black ABS fittings because they are: cheap(!!), readily available at any hardware/home center, easy to work with, "bullet proof," and they look pretty good mounted on the handlebars. The lightsize is almost identical to my now defunct NiteRider TrailRat, in fact I get a lot of comments from people mistaking it for the TriNewt (it is is dark afterall)

The design includes the following features:


A hefty heatsink constructed out of a 'stack' of thin aluminum discs 
Vented heatsink assembly to improve heat dissipation
Isolated waterproof chambers for the LEDs/Optics (forward) and electroncs (rear)
Integral knob connected to a switched potentiometer providing "Click" ON/OFF and dimming
Replacable triple Optics allowing both spot and medium beam combinations protected by a plexiglas lens cover

I am driving these with a 1000mA Buckpuck using a Lithium Ion 14.8V battery pack http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1147
I have now built two of these:

1) Triple Cree Q5 XR-E LEDs (Q5 bins) mounted on Triple PCB for MR16 http://cutter.com.au/proddetail.php?prod=cut683 with a Ktahod MR16 Optic http://cutter.com.au/proddetail.php?prod=cut561 and,

2) Seoul Semiconductors Z-Power LED Emitter (U-bin)s http://www.dealextreme.com/details.dx/sku.1445 and F'Form 20 mm: Spot and Medium Lens Optics http://www.ledsupply.com/20mm.php.

Both versions crank out the light and provide plenty of runtime for my 2-hour commute. This post describes construction of the Seoul Semiconductor version. This version of the light was a little more complicated to construct but was cheaper (Cutter is pricey) and provides flexibility to mix and match lenses.

If there is interest out there on MTBR.com (and it stops raining here in Sacramento) I'll post some beam shots and do some run time tests. My thanks to all the others out there who convinced me that LEDs were the way to go and shared their ideas and designs. Please feel free to use this information but do so at your own risk. Ride safely, and dim your light for oncoming riders!!! TomQuas









The design incorporates a heatsink assembly constructed out of aluminum discs that I cut with a holesaw. The design does require several common home shop tools including: Drill Stand, Router w/Flush Cutting and Chamfer Bits, Jig Saw, Soldering Iron, several hand taps and dies.









The heatsink is glued together using Artic Alumina (AA).









The various parts are shown here prior to assembly









The steps I followed to construct the light are as follows (Note the step numbers below correspond to the call outs in the following schematic):

_*(1) Threaded Nipple*_: Cut a thread along full length of a 2" piece of ¼" diameter aluminum tube using a 7mm x 1 die. Cut a ¾" deep thread on the inside of one end of the tube using a 10-24 tap.

_*(2) Heatsink*_: Cut 8 - 1½" x 0.032" aluminum discs using a 1-7/8" bimetal hole saw and 8 -1" x 0.032" discs using a 1-3/8" bimetal hole saw, thoroughly polish each disc using a drill mounted wire brush. (Or mount a stack of discs on a ¼" screw and insert into drill and use a file/sandpaper).

_*(3) LED Mounting Disc /Primary Heatsink*_: Cut 2 - 1-7/8" x 0.125" and 1 - 1-7/8" x 0.064" aluminum discs using a 2" bimetal hole saw. Do not cut pilot holes in the 0.125" discs. Create a ¼" primary" heatsink disc by gluing the 2- 0.125" discs together using AA. When dry drill a 15/16" center hole, then use a 7mm x 1 die to cut a thread. Thread the ¼" tube to be flush with surface of the 2" x ¼" disc.

_*(4) Housing Front Portion*_: Use a router with flush trimming bit to remove inside ridge in a 1½" ABS coupling. Apply double stick carpet tape to secure coupling to bench before routing. Use router with flush-cutting chamfer bit to chamfer inside front edge of 1½" ABS coupling. Use table saw to cut 1/8" kerf in coupling to secure lens gasket

_*(5) Plexiglas Lens Cover*_: Rough cut 2½" diameter lens cover from sheet of plexiglas using jigsaw. Trim plexiglas lens cover to size using a router with a chamfer bit. Before routing, temporarily secure plexiglas to top of the ABS coupling using double stick tape.

_*(6) Inner Sleeve & Heatsink Stack Assembly*_: Cut 1½" length of 1½" ABS pipe using chop saw or hand saw. Glue heatsink assembly alternating 1-½" and 1" discs using AA. Make sure heatsink assembly fits inside 1½" pipe inserted into coupling with heatsink, LED + optics, and plexiglas lens cover in place. With all pieces snug fit, mark the spot on the 1½" pipe insert where it extends above the 1½ " ABS coupling.

_*(7) LEDs, Optics and Wiring*_: Glue LEDs to ¼" x 1-7/8" disc using AA, use optics holders to uniformly position LEDs. Solder wires to LEDs in series. Thread LED wires through nipple, drill 3/32" holes in other end of nipple and thread wires. Solder wires to Switch Pot (7b) and Buckpuck (7b), and power cable (see Wiring Schematic). Use heatshrink tubing to protect all wire connections.

_*(8) Front Assembly/Vent Holes & Mounting Screw*_: Remove heatsink assembly and drill ¼" vent holes in 1½" ABS coupling with the 1½" pipe insert in place referencing mark in Step #6. Use masking tape to lay out hole pattern. Countersink the ¼" mounting screw hole. Dry fit lens cover, optics, and heatsink assembly in 1½" pipe insert and use ABS cement to glue insert into 1½" ABS coupling. Insert ¾" x ¼" mounting screw (8a) to make sure vent holes are aligned. Apply silicone sealant around back of heat sink.

_*(9) Rear Housing Assembly*_: Drill holes in 1½" ABS end cap for ¾" 10-24 screw (9a), Switch Pot (7b), and power cable. Assemble light fixture using 7mm x1 nuts and a ¾" 10-24 screw through ABS end cap to hold unit together. Apply O-rings as water seals.

_*(10) Rubber Gasket and Final Assembly*_: Trim inside of a rubber socket gasket (10a) (Ace # 1234) and fit over lens cover into 1/8" notch. Attach knob (10b) with set screw. Apply reflective tape. Attach to bars using ½" conduit clamp. Connect to power and pedal the night away!!!

Here is a schematic of the assembly


----------



## p97z (Dec 19, 2006)

Excellent work! Simple and creative...


----------



## mofoki (Feb 1, 2005)

I'm impressed. Your design incorporates methods that alot of those wanting to do a home diy LED light can do with some commonly aquired materials. And the fact that you used proven components like the buckpuck with lenses and lense holders which are inexpensive and give off a good beam pattern. Definately a nice little build.:thumbsup:


----------



## troutie-mtb (Sep 20, 2007)

I agree with mofoki there that is a good way to build a light with easily available tools

and what an easy way to make a heatsink it can be as large as you want .

these forums are great for the different ideas they throw up


----------



## [email protected] (Mar 28, 2007)

Very nice looking design. Also looks easy to build. I like the 1/4 inch threaded piece down the center that holds everything together. Looks like it should be easy to open the back and upgrade electronics if you need to do that later.

My only concern with the design is how well does it remove heat from the LEDs?

The heat sink looks like it would easily move heat into the center compartment, but do you get enough airflow thru the holes drilled around the circumference? Of course if the LEDs seem to be running warm, you can always drill more holes.

I wonder if there is any standard aluminum tubing you could use for the middle section of the light? I know that plumbing sizes typically have nothing to do with the actual diameter of the pipe, so it might be hard to find the right diameter tubing. If your heatsink was AA'd to the tubing, you'd likely get better heat dissipation with very minimal airflow, and you could skip the hole drilling step.

Mark


----------



## crisillo (Jul 3, 2004)

wow...very nice clean design! :thumbsup:


----------



## tomquas (Oct 27, 2007)

All-

Thanks for the kind words, I know I have learned lots from your previous posts.

Mhahn-

No problems with overheating. I know because I'm riding with two lights; one Halogen and one 3-LED. The Halogen serves as a "hand warmer" after my ride, while the LED light is still cool to the touch. I've found that if you provide reasonable heatsinking then as long as you're pedaling, overheating (the light not the rider!!) is not likely to be a problem!!

You're right the threaded tube does a good job of holding the unit together and it provides a conduit for the LED wires. The aluminum discs are all AA'd together; these have the much larger surface area that provide heat dissipation.

I like your idea to use a section of aluminum tube for the middle section. I think you'd want ~2" OD, but I'm not sure how you would connect it to ABS and finding the right tubing could be a chore. I did an earlier (unsuccessful) prototype with the larger heatsink discs 2" diameter so that they were exposed to the exterior of the housing. It looked cool but I couldn't quite figure out how to make weatherproof connections at either end

Cheers

-TomQuas

While I'm here, I'll post a couple more shots

This is the light and battery pack. I am using a Case Logic Digital Camera Pack for the battery which clips over the top bar

















Here is another view from the cockpit









This is a close-up of the battery pack installed. The quick release make it easy to detach the battery for charging. The camera pack isn't waterproof but the batterypack is completely shrinkwrapped. I've had this out in some pretty wet weather with no problems. On the other hand, I'm not real happy with the Tamaya connectors anymore...









Here is my commuter with both lights (Halogen + LED) mounted. I always try to dim for oncoming riders on the bike trail.


----------



## [email protected] (Mar 28, 2007)

Tom,

I see you are a fan of conduit hangers for handlebar mounts  . They are the cheapest, simplest, and sturdiest mount I have found yet. I like your use of heatshrink. I've done smaller pieces, just where the hanger rubs on the handlebars, but I really like the way yours looks.

How well does the screw thru the PCV into a nut hold the hanger in place? I've had problems with the nut above the hanger coming loose if you turn the light back and forth too much (this was on a halogen light design). Are you using some kind of thread locker?

Mark


----------



## tomquas (Oct 27, 2007)

Mark-

Yes a 1/2" conduit hanger works well. I've had some loosening problems in the past, now I embed the top of the mounting screw in JB Weld on the inside of the housing and use a nut above the hanger and locknut below. The heatshrink tubing helps add a little friction too. The trick is to have a very snug fit but still be able to make minor left/right adjustments.

Cheers

-Tom Quas

For this light I had to file the top of mounting screw to get a flush fit. The photo below was taken before it was JB Weld'ed in place. Since goes through 2 thicknesses of ABS pipe, it is quite secure


----------



## jetta_mike (Feb 26, 2007)

How exactly did you seperate the endcap from the hink sink area with the holes drilled? Or did i just miss it?


edit: By seperate I mean seal.


----------



## penquissciguy (Jan 22, 2008)

Nice light. Where did you get the potentiometer with switch?

Ken


----------



## tomquas (Oct 27, 2007)

Jetta_Mike-

I used silicone sealant around the perimeter of the leftmost heatsink disc. It's shown in the schematic as the light blue triangles. See Step 8

Ken-

I got the switched potentiometer at DigiKey http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CT2226-ND

This Switch Pot is very compact and works great but requires a knob for a 1/8" round shaft (e.g., needs a set screw to attach). I had a real hard time finding this. I finally found one locally (way overpriced @$6). Let me know if anyone has a better source.

Attached is a cost breakdown for constructing this light including purchase costs (e.g. items that you may only use a portion), per light cost, source, and links. I must admit, I was surprised when I added up the costs add it totaled ~$200 including battery and charger. I'd be interested in what costs others are incurring and where we may be able to find some cost savings.

-Tom


----------



## msxtr (Dec 10, 2006)

p97z said:


> Excellent work! Simple and creative...


Yes, I agree :thumbsup:

Greetings - Saludos

msxtr


----------



## mofoki (Feb 1, 2005)

Your ideas posted here sparked my creativity too. I'm using your method for fabricating the heatsink with the exception of the bolt. I'm still using the bolt idea but threading a 1/2" aluminum rod and then drilling out the center of the rod. It hardly weighs as much as a feather. The main part of the heatsink ( the part the leds mount to ) is 1/4" aluminum and the fins are all.090" aluminum. It looks like the iblaast. The back I haven't started yet but I imagine it will be just like the iblaast. It's coming along well so far and I'll get some pics posted once the back is done and the Maxflex and leds are here. I'm putting four Cree Q4's in it. I'm not going to enclose the heatsink though. I like that transformer look.


----------



## tomquas (Oct 27, 2007)

Hi Mofoki-

Your design sounds great, sparking creativity is a major benefit of these forums. You could use a progression of disc (fin) diameters to get that swoop look of the IBlaast. I'd love to see details especially how you connect the front/rear sections to the heatsink transformer. I just couldn't figure that out...

I'm just back from a great night ride (starry night, not too cold). It's when I do my best thinking. Tonight I came up with the perfect (?) name for marketing my bike light design. I thought I'd "pitch" it here. So here goes....

Introducing the​
*Tricyclops​*_Triple Bicycle Optical LED Lighting System_​
_OK so the acronym need a little work, but it's definitely cooler then TriNewt, that sounds like some kind of three-headed salamander(??).._.

The tag line would be something like:

_This three-eyed monster bike light projects a 600 lumen beam of mythical proportions..._​
_OK so there is a very good reason I'm not in marketing..._

Hey, yours could be the Quadcyclops!

-Tom


----------



## zemike (Sep 3, 2007)

This heatsink design is not very convenient and effective for the following reasons:
1) hard to manufacture (cutting, polishing)
2) heavy heatsink
3) too much thermal junctions (between the discs)

I'm thinking of a simpler design - take a regular heatsink, like this one:









saw off the protruding parts and you're done!

or use this heatsink and cut it to a round shape









the big pluses are:
1) less work
2) less weight
3) higher efficiency in thermal transfer


----------



## MyOtherRideisaCar (Feb 14, 2008)

I agree with the more efficient heat sink design, saves alot of work. Otherwise the light seems very well constructed. 

What kind of battery life do you have? 

And is there a high/low adjustment?


----------



## striegel (Dec 24, 2007)

Wow, an incredibly well-documented build! Kudos.


----------



## mofoki (Feb 1, 2005)

Ok tomquas, here's what I came up with after you gave me the idea, at least in part.
I purchased myself a magD and some .090 aluminum and .050 aluminum. I used the washer idea for the back half of this build except for the last three fins which are actually the tailcap of the mag flashlight. I did all the milling with the use of a drill, hacksaw blade, file, and emery cloth. I cut the mag head itself in two. I drilled three holes to attach the back half to the mag half. There is one center hole down all the parts which sandwiches the fins with a self threaded rod of aluminum and honed out in the middle and I used AA to make that assembly permenant. Then I drilled three holes to attach the mag ring with three 2mm bolts so that in the future I can access the thing for upgrades. Now the tail end of this is the mag tailcap which houses the BFlex perfectly. If you look closely I also put a non-conductive material in there to protect the board. I am lucky too that the switch that came with the board fits and can be used. That saves. I made a cover from aluminum that is also attached with 2mm bolts. The lense is a Khatod narrow beam pattern but it too can be changed. I'm building this one using three Q4's but with reflectors I could put four LED's in there. Those are on order for the next one I build. I really like this build and I think it is the one design I'm sticking to for future builds. It was pretty easy.


----------



## mofoki (Feb 1, 2005)

I didn't get all the pics in so here's a couple more


----------



## Guest (Feb 20, 2008)

mofoki,
I hope you don't mind but I think I will copy that idea :thumbsup:


----------



## notaknob (Apr 6, 2004)

*Nice!*



mofoki said:


> Ok tomquas, here's what I came up with after you gave me the idea, at least in part.Those are on order for the next one I build. I really like this build and I think it is the one design I'm sticking to for future builds. It was pretty easy.
> I didn't get all the pics in so here's a couple more


Damn, that's nice. I'd seen other Mag-D builds but that looks quite easy to duplicate.

I dub thee the mofoki-mag-d-mod (mmdm).

Which D cell mag is that? 2/3/4?


----------



## mofoki (Feb 1, 2005)

I post them here so you all can get ideas. If you want to build one feel free. If you need help just ask and I'll be glad to tell you how I did it.


----------



## notaknob (Apr 6, 2004)

*Maglite Cell #?*



mofoki said:


> I didn't get all the pics in so here's a couple more


Nice build mofoki.

Which Maglite - D cell did you use? 2, 3 or 4 cells?

//edit - noticed that all the C and D cells use a 57mm head... so doesn't really matter for this. Only difference I can see is the C cell end cap may be too small for the bFlex board.


----------



## mofoki (Feb 1, 2005)

notaknob said:


> Nice build mofoki.
> 
> Which Maglite - D cell did you use? 2, 3 or 4 cells?
> 
> //edit - noticed that all the C and D cells use a 57mm head... so doesn't really matter for this. Only difference I can see is the C cell end cap may be too small for the bFlex board.


The cheapest one I could find. I believe it's a 2D.


----------



## Guest (Feb 25, 2008)

mofoki, have you got it up and running yet? also it would be nice to see pics with it's bar mount in place, do you know what mount you will be using? Or maybe it's going on your head.


----------



## mofoki (Feb 1, 2005)

It's finished, except for the cushin pad that will be on the mounting to protect the helmet. The wire is a hard spring type steel used in the landing gear of the radio controlled airplanes, very strong stuff. When squeezed around the housing and inserted into the holes of the bracket it is very solid and doesn't require any other method to secure it. It's a good idea too because it would act as a give point or break-away if you ever hit into a low branch. In that case the light would simply slip out of the bracket and no damage would be done.


----------



## mofoki (Feb 1, 2005)

another pic. I forgot I have to sew a velcro strap to it too. I got all the programming of the bflex done and here it is turned on.


3 Cree Q4 LED's
1 Maglite D head and tailcap
1 6" x 12" sheet of .090 aluminum
1 6" x 12" sheet of .050 aluminumn
1 1/2" solid aluminum rod
1 Khatod 30* tripple lense
1 BFlex control board
1 waterproof connector cable ( Batteryspace)
artic alumina epoxy adhesive

total cost for this build about $135


----------



## eddielee70 (Dec 28, 2006)

mofoki, that is one fine well design light with a well thought out mount. can you tell us the weight with mount? our weather here doesn't require that much cooling fins like your design here and your other designs, so after 15 trail ride( 2 hour each) testing on my lights and 20 hour indoor fan testing. Mine are working well. I'm sure I don't want to use mine in 60F weather as it'll probably burn out.


----------



## mofoki (Feb 1, 2005)

I had it powered up last night just sitting on the windowseal and a fan blowing air on it. It stayed cold to the touch. I have the thermal protection set at 50C and it never tripped or dimmed. It ran for more than 3 1/2 hours until I had to shut it off to go to bed. The twin to this light ran 5 1/2 hours so I'm guessing this one to be about the same off a 14.4v 4800mA Li-ion pack.

To get the weight of it I will have to get the scale from work but let me say, it's light enough to wear as a helmet light.

I'm glad to hear your lights are working out well. I've had my share of magic smoke failiars and this design has proven itself so I think I'm done on the designing phases and now I'll just start mass producing them for people in my area who want them. I think if I were to actually market it I would probably get sued for patent infringement.:nono:


----------



## znomit (Dec 27, 2007)

Love the wire mounting idea! 
Thats original!
:thumbsup: :thumbsup: :thumbsup:


----------



## mofoki (Feb 1, 2005)

Now I'm faced with a delema :madman:


----------



## znomit (Dec 27, 2007)

I think you can fit them all on one helmet!


----------



## Guest (Feb 27, 2008)

Well done, that's very nice work indead.
You should be able to see where you are going without too many problems. I still can't believe the speed that you work as you seem to have made these things in the time that it takes me to drill a hole in a bit of ali.


----------



## tomquas (Oct 27, 2007)

All--

I've been in Mexico on vacation for a couple of weeks and deliberately stayed "off the grid" 

Zemike--

Thanks for the constructive remarks and your ideas; I'd agree that using pre-fabricated engineered heatsink has benefits. I think we would all love to see your ideas implemented in a DIY light build.

Myotherrideisacar--

The Switched Potentiometer works like a rotary dimmer switch. It "clicks" on and then you rotate the knob clockwise to "infinitely" adjust the brightness setting from low to bright. There is no pre-set "high" and "low" setting. 

I haven't been able to determine maximum battery life, it's >2.5 hours (my longest ride) with the light mostly on maximum (1AMP) setting.

Mofoki--

Wow, you've been busy!! Very nice light! I really like the way you tapered the edges of the aluminum washers, looks very professional. I expect there will be a lot of "decapitated" Mag flashlights as a result of your posts. I haven't used a helmet light yet, but your design may convince to try to build one of these myself!

The mount is very clever, what kind of wire is that and how did you get such a precise bend or did it come that way from the RC Airplane parts? Where did you get the aluminum base plate(s) for the mount?

Did you have to do anything to weatherproof the switch or cable?


----------



## Hack On Wheels (Apr 29, 2006)

mofoki said:


> I post them here so you all can get ideas. If you want to build one feel free. If you need help just ask and I'll be glad to tell you how I did it.


The more detailed instructions the better! I would love to make one of these for running on the bars after I finally finish my achesalot style helmet light. Would you be able to photograph the process step by step when you make the next one? Brilliant work, very impressive!


----------



## mofoki (Feb 1, 2005)

Thank you for your positive thoughts about this but you're the one who got me started with the design. That rod is just some strong steel that comes in a three foot length and in lots of different diameters. I bent it into the shape I needed but it wasn't easy. It's some of the toughest stuff I've seen. I bracket for the helmet mount is two pieces, one flat .090 aluminum and the other was from a chunk I cut up that I had lying around but it's about a 1/4" thick and I cut the shape close to what I wanted and filed it to finish. I then dremeled the cutouts for the velcro strap and just screwed and glued the two together. Drilled two holes for the wire to slide into and presto, a simple helmet mount bracket. This was a good design because it actually weighs less than just modding a mag head and it stays alot cooler too. I particularly like the tailcap of the maglite because the bflex fit perfectly. I only finned it to lighten it up but it doubles in heat removal properties also. You guys were saying how quick I put this together but it is actually so easy it didn't take long at all. Thank you for inspiring me to accomplish it.


----------

