How I Built My Own MTB Light

[BrewMaster]

I built my own MTB light this week and rode with it at the Loop on Thursday night. A few people asked me to post up what I did and how I did it, so here we go.

First, this is not my design, so all the credit goes to "dan" on Instructables.com. Here is the design I followed.

My light burned for about 3 hours. Low and high settings were pretty close in brightness since I used only 1 dimmer switch with a 1000 ohm resistor. I may up this to 3000 ohms to see how it works for a low setting.

This light was as bright if not brighter than any light out at the Loop on Thursday. It lit up the whole trail and I had no problem riding at a good clip. I thought the cyan (green) LEDs made it easier to see definition in the trail. I think someone called this light "green terror."

The instructions were pretty easy to follow. I have very little knowledge of electrical engineering and I had never soldered before this week. This was a fun project that was really not very difficult. With a few screw ups, it took me about 3 hours. I could probably do it again in about 1.5 hours. All together I think I spent about $70-$80 building this bright light including buying a nice 8 cell NiMH battery charger.

Here are some of my step by step pics.

Get an old computer heat sink and solder the LEDs into the configuration laid out by Dan. Use thermal compound (the white goop) to improve thermal transfer to the heat sink. LEDs get hot, so this is important.


I sealed and glued the LEDs to the heat sink with clear silicone sealant/adhesive.


Snap the lens holders over the LEDs and allow the silicone to glue them in place. Leave the silicone to cure for a while.


Eventually you will snap the lenses into the lens holders. You can do this anytime. Don't glue them in. They snap tightly to the lens holders and can be changed to different angle lenses if you want a different beam pattern.




Next I got my buckpuck and switches out to start soldering them together. The black switch is the main on/off switch. The yellow one is the dimmer to cut down power for longer life. Note: I only used 1 dimmer switch unlike Dan's design with 2.


You have to bend the connector on the black switch with the hole in it so it fits the Voltage In pin on the buckpuck nicely. This makes soldering it much easier since the line up perfectly.




Begin soldering this mess together per the instructions. Notice how crappy my solder connections are? The hardest part for me was soldering with the pins so close together without shorting a connection. I ended up intentionally bending a few pins on the buckpuck to get more clearance.




Next we start putting together the battery pack. These battery holders are cheap and can be found at Radio Shack or online. I just glued them back to back with the silicone adhesive.


Solder the black wire from one holder to the red wire of the other holder. Cover it with a butt connector or electrical tape to protect it.




The remaining black and red wires are your connections to the buckpuck.


I put connectors between the battery and the buck puck In case I want to try different battery configurations down the line. This also makes it easier to pack.


At this point you need to finish soldering your connections to the buckpuck. Here is a picture of the final soldered assembly.




I originally wanted to attach this to my helmet, but I didn't find a sturdy way to mount it, so this became a handle bar mounted light. I took an old biker reflector and glued/zip-tied the heat sink to the face of the reflector. Pretty simple actually.






When you are all done, here's what you've got, including a messy workshop/dining room table. These lit up pics were taken after it had been running for 3 hours.









Here are a few things I learned along the way that I would recommend to anyone building this light.

First, get good velcro straps to hold it all to your bike. The wires I had were way too long for a handlebar mount, so I strapped them to the top tube. The battery pack was placed in an old camera case and strapped to my seat post. These velcro straps from Lowes are about $4 for 3 straps and work very very well since they have the eyelet.



I am using 8 Energizer 2500 mAh rechargeable NiMH batteries from Target. This was the best deal I found. Higher mAh rating should give longer burn time from the light.

Use a multimeter to check your connections. My light didn't work at first, then I found a bad joint in my battery connections.

When I build another one of these, I would use different switches and probably not glue them to the buckpuck. I want the switches mounted away from the buck puck, maybe on my bars, so I would probably wire them and get bigger thumb switches more like this:



Also, the hollowed out rope is a good idea for covering the wires. This makes it easier to handle. Don't skip this step like I almost did.

I encourage anyone to try this project. It's fun and a good way to get a bright light without dropping hundreds of dollars.

Feel free to ask questions. I would be glad to help anyone try this project.

[DirtRider]

Awesome home build project!!! What was the total cost invested when you were all done?? How do they behave on the trails??

[BrewMaster]

Well, altogether I spent about $100, but that included shipping from Digikey and Future Electronics, Digikey's stupid ass $5 handling charge and things like thermal compound, wire, adhesive, connectors, etc of which I have plenty of each left over. To actually build this it only took about $70 worth of stuff.

If I do it again, I would buy most of my parts at Future Electronics and Radio Shack to save shipping. Digikey was pretty annoying to deal with and they brought no value to my design with their crappy switches, overpriced shipping, and slow delivery.

The light behaves perfectly on the trail. It's stable and bright with great vision of trail features.

[Dino Brown]

The light BREWMASTER pedaled around the Fully Loop was pretty impressive! He (admittedly) has a bit of "fine tuning" to do. I can already see him showing up each week with a NEW improvement. Too funny!

The green light (while the butt of jokes) did indeed provide a clean view of the trail. Surprising. Much better than the GHOST WHITE light produced by many older HID and LED lights.

If you have the time, patience and love the smell of solder- go for it! If not, The Path... Jenson... Adrenaline.. Bike Co.... Surf City... Switchback may have what you are looking for.

If you haven't been on a night ride- your missing out!
Don't take my word for it-- ask Brewmaster! Thursday was his first EVER night ride! See you Thursday!

P.S.- What would happen if you had two "flood" lamps on the bottom and two "beam" lamps on top? Would that work?

[el_d00der1n0]

Thanks for posting this.

Years ago in the Houston area (where I'm from originally) we had electronics parts places. They were like the home brew mart for hobbyists. The one I frequented was huge. A whole 50' row for resisters and pots for example. Does such an animal exist anymore? Does anyone know of one in the SD area?

[Dino Brown]

Orvacs in Fullerton.

There is a place in Burbank and another in Glendale... Help!!!

[OTHRIDER]

P.S.- What would happen if you had a "flood" lamps on the bottom and two "beam" lamps on top? Would that work?

Dino,

I'm pretty sure Sam said he could switch out the lenses to obtain different spread patterns. I too thought the "Green Hornet" was easy on the eyes. Perfect output for the Loop. Good job Sam!

[Dino Brown]

Time for Brewmaster to experiment! With a bit more distance (i.e. spot)... WOW!
He was ALREADY "thinking about" building a headlight!

[sailcalifornia]

I have been looking at these on instructables for a while, but have been intimidated by the soldering. However if this was your first time and made it with little problems i think i am going to have to give this a try.

[COLEKO]

Originally Posted by Dino Brown

Orvacs in Fullerton.

There is a place in Burbank and another in Glendale... Help!!!

Ford Electronics on [FONT=Arial][SIZE=3]Commonwealth Avenue. Thats where I go for my soldering supplies[/SIZE][/FONT]
[FONT=Arial][/FONT]
[FONT=Arial][SIZE=3]Orvacs is cool. I used to go there for motors and fans. They also have a nice selection on switches . [/SIZE][/FONT]

[nappyt]

Originally Posted by el_d00der1n0

Thanks for posting this.

Years ago in the Houston area (where I'm from originally) we had electronics parts places. They were like the home brew mart for hobbyists. The one I frequented was huge. A whole 50' row for resisters and pots for example. Does such an animal exist anymore? Does anyone know of one in the SD area?

SD Electronic Supply is where I go. More junk yard than parts store but between there and Fry's I've never not found what I'm looking for.

http://www.sdelectronicsupply.com/
San Diego Electronic Supply
8148 Ronson Rd Suite E,
San Diego ,CA 92111 –
Phone: (85 278-1245
Monday - Saturday 9:00 am - 5:30 pm

Here are a few links from a local linux club I know...

Electronic Parts and Miscellaneous Junk

• Murphy's Surplus http://www.murphyjunk.bizland.com/
• Industrial Liquidators http://www.industrialliquidators.com/
• Willy's Electronics http://shop.willyselectronics.com/index.htm
• UCSD Surplus Sales http://surplus.ucsd.edu/
• San Diego Electronic Supply http://www.sdelectronicsupply.com/

[Dino Brown]

Sailcalifornia- Nice of you to join us again! Where you been? Get yourself a light Junior!

Coleko- Ford Electronics is also a VERY cool store. Clean... Great selection... knowledgeable staff (i.e. can direct you to other places if need be). In many way, I like it more than Orvac! With that said, the selection at Orvac (including junk parts, overruns, obsolete parts etc.) make it tough to beat!

[OffRoadie]

Originally Posted by nappyt

SD Electronic Supply is where I go. More junk yard than parts store but between there and Fry's I've never not found what I'm looking for.

http://www.sdelectronicsupply.com/
San Diego Electronic Supply
8148 Ronson Rd Suite E,
San Diego ,CA 92111 –
Phone: (85 278-1245
Monday - Saturday 9:00 am - 5:30 pm

Here are a few links from a local linux club I know...

Electronic Parts and Miscellaneous Junk

• Murphy's Surplus http://www.murphyjunk.bizland.com/
• Industrial Liquidators http://www.industrialliquidators.com/
• Willy's Electronics http://shop.willyselectronics.com/index.htm
• UCSD Surplus Sales http://surplus.ucsd.edu/
• San Diego Electronic Supply http://www.sdelectronicsupply.com/

No way man! Is that place like the new Gateway Electronics?

BTW, Mouser Electronics has a distribution center in East San Diego County. If you order from them, sometimes you get it the next day even if you pick ground shipping. I think you can also Will Call. Their website sucks compared to Digikey's though.

http://www.mouser.com

[tkblazer]

Originally Posted by Dino Brown

Time for Brewmaster to experiment! With a bit more distance (i.e. spot)... WOW!
He was ALREADY "thinking about" building a headlight!

this site has cool pictures of different lens optics and beam patterns

http://www.led-spot.com/index.shtml

once i get some free time i'm gonna try to build one of these... i know we have a few machinist here on STR, would be cool to see some of their possible housing designs

[nappyt]

Originally Posted by OffRoadie

No way man! Is that place like the new Gateway Electronics?

BTW, Mouser Electronics has a distribution center in East San Diego County. If you order from them, sometimes you get it the next day even if you pick ground shipping. I think you can also Will Call. Their website sucks compared to Digikey's though.

http://www.mouser.com

Yes, I think they bought the GW elect stock from them when they closed.

Can you do Will Call with Mouser? I have a catalog they send out every few months. I thought it was only via mail. Its been a couple years since I ordered anything. Thanks for reminding me about them.... I do like the Digikeys online catalog though...