How to: Super bright DIY LED bar

[Jim85IROC]

Over the last few weeks, I've been working on my own DIY LED light bar. I wanted to see how good a DIY bar could be compared to the commercially available stuff. I used the OneTooManyRCs light bar on my Bomber as a comparison.

Bomber light:

I started out with a couple different COB-style LED bars from Ebay. I bought a set that's advertised as a "Daytime running light" for cars. It runs on 12V, so it's a perfect match for 3S. The other bar that I chose was a bare COB LED bar that measures 10mm x 120mm. This bar is also designed for use with 12V. I liked this smaller size, but wasn't sure how the brightness would compare. Links to both lights are below.

The two styles:

For a housing, I bought some extruded aluminum C-channel from the local hardware store. For about $8 you get 4', which is enough to make about 8 of the bars if you're feeling ambitious.

For mounts, there are a few options. I started by making my own out of Kydex, but decided that I wanted something a bit more professional looking, so I decided to design them in 3D CAD and print them on my 3D printer. I went through a number of designs, and I'll throw them on Thingiverse as soon as I clean up the files. For those that don't have a 3D printer, you can make your own from Kydex like I did, or by utilizing some corner braces from the hardware store. You can even use some of the extra c-channel if you cut one of the sections off. If people are interested in buying the 3D printed mounts, I can throw them on Shapeways, but the cost may be too high to make sense.

A couple of my printed designs:

The 1/2" bar with the rigid mounts:

Closeup of the tall rigid 3/8" mount installed:

Closeup of the short adjustable mount installed:

My last design is angled to work on the sloped area just behind the windshield:

Below is a step by step procedure as well as a bill of materials and required tools. Here's the video:



<iframe width="640" height="360" src="https://www.youtube.com/embed/2xyY2dTb8Nk" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

here's a direct link incase the embed doesn't work:
https://youtu.be/2xyY2dTb8Nk


My apologies if some of this looks wonky. I typed this up in Word, and I can't figure out how to import it without it changing the color of the text, so I had to manually reformat it all.

Parts Needed<?xml:namespace prefix = "o" ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
· 3/8” or ½” aluminum c-channel ($6-8 for 4’), or ½” aluminum angle<o></o>
· LED Bar ($2-$5)<o></o>
o “DRL” Style: https://www.ebay.com/itm/4-Pcs-New-White-Ultra-Thin-14CM-Waterproof-COB-LED-DRL-Fog-Driving-Lights-12V-DC/391322439119?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649<o></o>
o “Bare” style: https://www.ebay.com/itm/12V-10W-300LM-LED-Strip-Bar-COB-Light-Lamp-Home-Party-DIY-Nightlight-120x10mm/112556129272?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649<o></o>
· Mounts<o></o>
o 3D Printed: (Thingiverse link is coming!)<o></o>
o Corner braces: https://www.homedepot.com/p/Everbilt-1-in-Steel-Zinc-Plated-Corner-Brace-4-Pack-13619/203170051<o></o>
o DIY of some sort<o></o>
· 8x M3x8mm panhead or buttonhead screws (for mounting to the body)<o></o>
· 4x M3 lock nuts (for mounting to the body)<o></o>
· 4x M2x4mm countersunk (optional) screws (For mounting to the c-channel) – use M2x6mm if you don’t use countersunk)<o></o>
· 4x M3x6mm panhead or buttonhead screws (For mounting uprights to the c-channel inserts<o></o>
· JST Plugs: https://www.ebay.com/itm/JST-RCY-Male-Female-Connector-Housing-Plug-with-Crimp-terminal-x-50-SETS/112284285175?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649<o></o>
<o></o>
Tools Required<o></o>
· Saw capable of cutting aluminum (Hacksaw, sawzall, etc)<o></o>
· File and/or sandpaper<o></o>
· Dremel<o></o>
· Sander/shaper<o></o>
· Drill & drillbits (1/16, 5/64, 7/64, 1/8, 1/4-ish)<o></o>
· Body reamer (optional)<o></o>
· 90˚ countersink bit (optional)<o></o>
· JST style crimp tool (https://hobbyking.com/en_us/hobbyking-jst-sh-connector-crimping-tool.html) $15<o></o>
· Needle nose pliers and/or 5mm wrench<o></o>
The procedure is too long to fit into this post, so I'll stick it below.

 

[Jim85IROC]

My apologies for the lousy formatting. Apparently Vbulletin handles bullets a hell of a lot better than it handles numbered lists. :-/

Closeup of the bar from the top:

The bar on the truck:

Procedure
1. Identify which size c-channel you need for your LED light. The “DRL” style lights fit into the ½” housing after some sanding. The 10mm “bare” style lights fit into the 3/8” housing after some sanding
2. Cut c-channel to length 1/16” longer than the LED bar to create the aluminum housing
a. If you’re cutting by hand, make sure it’s long enough that you can square up the ends and still have the correct finished length
3. Remove LED bar from its existing housing if your style has that
4. Carefully sand the LED bar until it fits smoothly inside of the aluminum C-channel housing
a. A benchtop belt sander works best for this, but taping sandpaper to a workbench will work too
b. Use sandpaper or file to deburr the edges
5. Solder 12-18” of wire to the LED bar if required
6. Install LED bar into the aluminum housing & identify where you need to create clearance for the wire. Use file or dremel to notch the housing
a. You want the wire to fit fully within the notch you create so that the mount will seat properly.
7. Print your desired mounts, or proceed with building your own
a. If printing, make sure to print the drill template as well. If making your own mounts, use the following instructions:
i. Using 1/8” Kydex or ABS, cut out 4 small pieces for the parts that will go into the c-channel, and if you’re making your own uprights, 2 larger pieces for those.
ii. Glue the two small pieces together, then shape with sander/sandpaper/file until they fit snugly inside of the c-channel. The final product should sit flush with the outside of the c-channel when the LED bar is installed.
b. Utilize the steel angle brackets for the uprights, or use the following instructions to make your own:
i. Shape the upright mounts as desired, but make sure they are a mirror image to each other.
ii. Use heat to bend the upright mounts. To do this neatly and accurately, both pieces should be clamped into a bench vise (or a home-made setup using some paint sticks & clamps of some sort). Heat and bend. Hold in position (with a block of wood, not your bare hands!) until cool.
c. Locate and drill 1/8” mounting holes in bottom of upright mounts (Suggest 2 per side)
d. Locate a position in the upright mounts to Drill a 7/64” hole to attach the uprights to the c-channel inserts.
i. Pick a spot that will be centered on the smaller inserts inside of the aluminum housing
e. Use a scribe (or a drill bit) to transfer the hole to the middle of the smaller pieces that go inside the aluminum housing, then drill those with the 7/64” drill bit
8. Drill your holes in the aluminum housing
a. If using 3d Printed mounts, utilize drill template to locate & drill 1/16” holes in the aluminum housing
b. There will be one hole on the top and one on the bottom of each side, for a total of 4. Be sure that the drill template is oriented properly each time
c. If using your own mounts, identify the best location for the mounting holes and drill. Making your own template from some scrap material is strongly advised
9. Deburr the inside of the aluminum housing
10. For the adjustable mounts, use the M3x6mm screws to assemble them.
11. Install the LED bar into the housing, followed by the mounts.
12. Drill 1/16” hole approximately 4mm deep into mounts through the holes that you just drilled in the aluminum housing.
a. Make sure the mounts are positioned properly and don’t move
b. It’s strongly recommended that you use a drill press for this if you have one. Crooked holes could reduce the clamping force of the screws or interfere with the other mounting hardware in the inserts
13. Remove mounts from housing, & chase the holes in the mounts with the 1/16 drill bit again.
14. Run a 2mm screw in and out of each of the mount holes to cut the threads
15. Use the 5/64 drill bit to enlarge the 4 holes in the aluminum housing
16. Deburr the inside of the aluminum housing
17. If you plan to countersink the mounting screws, use your 90˚ countersink bit in the drill press, and go slowly, checking fitment with one of your countersunk screws. Remember that it’s always easier to take away a little more material than it is to put some back!
18. Reinstall the mounts and insert the screws through the aluminum housing. Don’t overtighten!
19. To transfer your mounting holes to the car body, make a template using some paper and/or tape.
20. Once transferred to the body, drill or ream the holes to 1/8”
21. Set the light bar in place and mark an appropriate spot to drill/ream a hole for your wires to pass through.
a. Be mindful of the connector you choose to use, and drill/ream the hole to an appropriate size. ¼” should work for the red JST connectors like I’m using.
22. Attach your preferred connector to the other end of the wire
a. In my case, I’m using the standard JST plug, since these are common for various power systems, and some smaller batteries come prewired for this plug.
b. Make sure that you choose a gender that will allow you to plug directly into a battery. This will also benefit you if you tie directly into your ESC battery connector because it’ll allow you to plug in other devices that use this same plug.
c. Strip back a little more than 1/8” of the jacket off the ends of the wires, and use the JST crimp tool to crimp the appropriate pins/sockets to the end of the wires.
d. Insert the pins/sockets into the plastic housing until they lock into place.
e. Alternately, if you don’t want to invest in the JST crimp tool, you could just buy the plug with pigtails already on it and solder to your wire, but be sure that the ones you buy come with an adequate wire gauge.
23. If using the adjustable or DIY mounts, remove the vertical portion of the mounts, and using the M3x8mm screws & M3 lock nuts, install the vertical mounts to the body by inserting the screws from the top and fastening to the underside of the body with the M3 nuts.
a. If you’re using the one-piece printed mounts, you’ll need to insert the screws from underneath and use the nuts on top of the mounts. You’ll need a thin 5mm wrench or needle nose pliers to prevent the nuts from spinning as you tighten the screws
One note about power: These lights will not work at all with 2S voltage levels. They need 12V (or close to it) in order to work. If you run a 2S setup on your vehicle, you’ll need a separate ~12v (3S) battery to power the lights, or you’ll need to use a boost converter to raise the voltage up to 12V.

 

[Hydrocarbon92]

That's a great write-up. I bought 4x of the bigger types but forgot about them til now.

One thing I noticed is the 120mm "bare" style only has 1 row of LED's and the 140mm looks to have 2 rows. Do you notice a difference in brightness? Mine are 170mm with two rows, and I plan to cut them down. From what I saw in a thread a while back you can cut them down w/o ill effects.

 

[Jim85IROC]

The 120mm bare light is substantially brighter than the 140mm "DRL" light. I was shocked by this. I didn't expect the smaller light to be brighter. I do a comparison in the video toward the end to show the difference.

I can't be sure, but if I had to guess, I'd say that since the "DRL" is designed to work in a 14.4v automotive system that it may have a higher series resistance, which is making it dimmer on 12V than the light that's designed for only 12V. When my boost converters get here I'm going to try running the DRL at 14v to see what happens.

 

[Hydrocarbon92]

I tried splitting mine, offset so I'd have a smaller & larger, but it didn't work as planned. The double-row LED strips seem to have them in 4 groups in series to divide voltage by 4 instead of using resistors. 14v probably is the sweet spot. The smaller strips are probably designed for 12v with a resistor per individual LED, which is why they'd be brighter.

The interesting part is I can make 2x 3" 6-7v lights out of each strip if I want. I just had to decipher how the circuit was routed.

 

[Jim85IROC]

Pics added and the youtube embed code is apparently fixed.

 

[Phins Fan]

Great video and tutorial. Seems easy enough to fab up. Any idea how the lights are with water?

 

[Jim85IROC]

The DRL style lights are advertised as waterproof, and the bare bar has exactly the same construction, so it should be OK, but I haven't tried it.

 

[Phins Fan]

For the minimal cost of investment it'll be worth the shot. I'll be ordering up supplies this week

 

[Hydrocarbon92]

The COB style lights are naturally waterproof since they sit behind a coating of silicone. You'll still want to coat the solder pads & wires, otherwise the tin & wires could corrode (white/green mess). WD40 might be enough, but also coat the exposed aluminum sides.

Jim any update on the thingiverse files?

 

[Jim85IROC]

Files have been uploaded to Thingiverse. I didn't have time to mirror and rotate all of them in Fusion 360, so when you pull some of them into your slicer, you'll have to create a mirror copy and re-orient them so that the longest part (the vertical upright) is laying on the bed.

https://www.thingiverse.com/thing:2782193

 

[happymachinist]

Excellent idea!! And thanks for the links!


Sent from my iPhone using Tapatalk Pro

 

[le varan]

Hi Jim,

Just received my leds from eBay, was excited to see the power with 3S.
Soldered the wire and connected it to my battery, tried the red one.
Started heating like hell couldn't keep my hand on it, took the temp with a IR gun went up to 60°C, 1 min later started blinking and faded out.
Doesn't work anymore : any idea on what went wrong ?
Thanks
LV

Envoyé de mon SM-G930F en utilisant Tapatalk

 

[Jim85IROC]

I'm not sure, but it sounds like based on the blinking that you overheated something. I'm not sure if these LED bars have any current limiting resistors hidden under the aluminum panel, but it sounds to me like if it does, that burned up. I assume that these don't have any sort of current limiting resistor (resistors are typically big enough that their location is pretty obvious), and if that's the case, then you probably smoked the LEDs. Good thing they're cheap!

 

[le varan]

I'm not sure, but it sounds like based on the blinking that you overheated something. I'm not sure if these LED bars have any current limiting resistors hidden under the aluminum panel, but it sounds to me like if it does, that burned up. I assume that these don't have any sort of current limiting resistor (resistors are typically big enough that their location is pretty obvious), and if that's the case, then you probably smoked the LEDs. Good thing they're cheap!

I'll try an other one.
Do they work on 2S ?

LV

Envoyé de mon SM-G930F en utilisant Tapatalk

 

[Jim85IROC]

I'll try an other one.
Do they work on 2S ?

LV

Envoyé de mon SM-G930F en utilisant Tapatalk

No, they won't even come on at 2S voltage. You need to run on 3S, run an auxiliary 3S pack for the lights, or install a boost converter to bring the voltage up. The boost converter is the best option if you want to stay with 2S because it's tiny & light weight, and doesn't require a second battery. It's how I plan to use this one if I ever get the time to solder one up.

 

[JatoTheRipper]

Very cool. I bought some of those LED strips on eBay, but haven't done anything with them. Nice work.