Let's talk DIY lights


@dbrn32 are these real? Do they really make 80w led spot lights? Im gonna post the specs in a sec



Theres no reviews for them


S@ktreez420 I’m back a little sooner than expected. No problem about the rail, I just noticed you didn’t mention it the 2nd time around. If you’re pretty confident you can build the rail, you’re gonna be in good shape. It’s not very difficult, but will definitely be the most labor intensive part of the project. Mounting the cobs and wiring the driver will be much easier than you’re probably expecting. After the first one or 2, the last couple will literally take no time at all.

So back to the wiring. I said 18 awg mtw. Not much to this… the 18 awg is the size of the copper. If you’re not already aware, the copper gets bigger as the awg # gets smaller. All the way to zero anyway, then they become 1/0, 2/0 and so on. Outside of being an electrician you probably won’t ever have a reason to work with anything bigger than say 8 awg so don’t really worry about that to much. So basically comes down to bigger wire is good for more current (amps). The 18 awg is typically rated for 7 amps. There are some correction factors for long runs of wire or extreme temperature, but nothing like that should come into play on the average light build. The typical 15 amp circuit in your house will be wired with 14 awg for reference, that’s 2 sizes bigger than the 18. For this build a 20 awg would probably do, but there’s no sense in being any closer to your rated current draw.
The 18 is plenty workable and will give you a little safety factor. You wouldn’t want to go to the 16 awg in this case though, because it doesn’t fit great into the connectors on the cob. 18 should be good for just about any of these projects that I would advise on. so no harm in buying bulk and saving money. The mtw is simply the type of insulation used. There are several different types, so don’t sweat this much. It’s a very common type of insulation used in industrial controls. Hence the reason I have a large spool of it at my disposal haha. Your wire doesn’t need to be mtw, or any specific insulation. I would look for these specific features.

18awg copper (tinned is fine means the strands are fused with solder like substance)

Good for 600 volts

Rated for 90 degrees Celsius

This should be available on amazon from 10 to 500 ft rolls. I’m guessing $20ish for a hundred foot roll. Maybe more or less, haven’t shopped there for it but you should definitely expect the price per foot to go down with larger quantity. Something to keep in mind if you plan on doing another. But I would get 25 foot roll at the least.

The so cord is just another type of cable. It will have multiple individually insulated wires inside of it. Can usually be bought by the foot at local hardware store or Home Depot, or by the roll. It’s literally bulk extension cord without the ends. You will see this labeled as 16/3 type so. The 16 is the size of the individual wires, and the 3 represents the number of individual wires within the cable. If you decide to go with so cable or just cut the ends off an extension cord, here’s what you need to think about to determine how much you need. Are you going to remote install the driver outside of tent?

If you answered yes- get enough so cord or extension cord to run from the driver to the outlet you plan to use. Measure exactly how you plan to run it. Tuck, turn, or whatever you plan to do then add a couple feet. If you want to eventually run multiple drivers off this cord size it to 14/3. Then measure from your driver location to the tallest point you can hang your light. If you plan on running your cable up the corner of your tent or wherever, make sure to measure for it. Then add the height of your tent (or as low as you plan to be able to lower the light) and add a couple feet to that too. Get this length in 16/2. 16/3 is fine you will just have an extra wire, but the 16/2 should be cheaper. Also, add 2 more wago connectors. I didn’t think about this aspect earlier, sorry.

If you answered no and plan on mounting driver directly to the frame. Measure from driver to outlet you plan on using accounting for tucking and tying your cord, then add amount you plan on being able to lower light plus a couple feet. This can be 16/3. If you plan to run another driver off this same cable in the future, get 14/3 now as well.

In either case, if you opt for so type cord, you will also need a male end to hook up to the cable and plug into your receptacle. A cheap one is around 3-4 bucks. If you go this route, spend an extra couple bucks and get one that looks sturdy, your cobs will last a long time. You’ll want your cable to ad well.

I’m gonna be completely honest, the cheapest here will probably be buying a large extension cord and cutting it into 2 pieces. But we’ll see what you come up with for lengths first.

Probably a lot of babbling there. If I have time, maybe I can draw a picture tomorrow if you’d like.


The 80 watts is probably not the actual draw of the light, more than likely it’s an equivalent to type of number. But there’s not enough there to tell for sure. I would expect that to draw about the same as other led flood lights, 20-40 watts.


Did you see where ktreez found the deal on the white version of these type of flood lights for a couple dollars? If you’re looking to add something like this for flowering, look for the deal he got but in 2700k.

Generally I wouldn’t mess with these type bulbs, but if you can grab them for cheap like he did, go for it. I think he said Walmart clearance aisle.


Thank you sir!


Great info as always @dbrn32! And yes please, a picture is perfect for someone like me lol! I will start my wire search tomorrow, I’m smoking my nightly blunt then passing out. I’m leaving at 9 am to go to OC, MD for the weekend with my gf and her family.

I added 2 more wago’s to my cart, no biggie! And I was just at Home Depot and was looking at the outlet sections where I saw the outlet connector for a wire, so now that you say I’ll need one I already know exactly what to look for!

I also have old extension cords my dad has lying around, he used to splice them and fix them when one would rip or break, but I’m pretty sure there are a bunch of them still around, I’ll look! Also, I KNOW he has extra wiring around, like house light bulb fixture wiring. He re-did the entire house when they first bought it, so there’s TONS of extras around the house I can go look for tomorrow! I’ll let you know what I come up with and make sure to take pictures for you too. I think I’ll be able to get away with spending under $280 for the entire build, including parts and shipping for everything!

I’m getting so excited for this guys! It won’t be for another 3 weeks, but still…super excited! Thank you so much @dbrn32 for all the help! You are truly an awesome person for this! Mad respect and much love goes out to you brother!



And I hate to be that guy lol, but can you be even more specific with the wiring? Please haha? I typed it into Amazon and got tons of different looking wires! I get the extension cord and 16/2 and all of that lol, but a little more help with the 18awg pretty please? You’re the man, thanks @dbrn32

Would this work? I chose the 18awg option, 35’ and it says it’s rated for 600v and 105 degrees c



The specs on that wire are fine for this application, but the 12 awg is going to be to big. I don’t think it will fit in the connectors on the cob. I’m going to attach one that I found real quick. You can feel free to shop around for a better price.


It looked like 35 feet of this stuff was around 8-10, 100 feet little over 20, and 500 feet like $33. Just look around abd see if you can find anything better.


I didn’t see they had 18 awg in first read sorry, that should work.

As far as grabbing some cords from your dad, that should work. I would caution using anything that has splices in it, with watering and such that usually happens in grow room. But if you can save a few bucks that will work. If nothing else, you can usually find a cheap new one. We don’t need a heavy duty expensive cord for this build.


@ktreez420 sorry I have a lot going on. Wasn’t able to draw you up a diagram, buy I’m going to link a video that should help you out for now.

As far as the wago connectors, consider them fancy wire nuts. The benefits you get from the wago is that they are more sturdy, and you’re able to glue them to your light frame or wherever and still easily remove/add wire.


@ktreez420 here is a rough sketch of what your wiring would look like with a frame mounted driver. Sorry about the delay.


And here is another crappy sketch that would be more of a remote driver set up.


And if you want to run 2 light frames from the same cord, change the wago 412’s in blue circle to wago 413’s. This will allow you an additional wire port, you would simply attach your additional light frame to that additional port replicating the first fixture. And, change your multi conductor cable circled in red to at least a 14/3. This will allow plenty of current rating for both drivers.


You’re the man @dbrn32 I really appreciate that!! I think I understand the wiring aspect of it, but sometimes the differing colors of the wires make me question what I’m going lol!

Is there anything I’ll need to solder or will I be fine? I’ve never soldered anything lol, but I always wanted to learn anyway. I’m getting so excited to get this build underway!

Rapid said they would match Arrow’s price, and they also answered me about the info I requested on their heat sinks, they said this;

“We’ve done testing on our heatsink but I don’t have testing data to share. Basically we’re comfortable running the VERO (D) COBs at up to 1.75A with no active cooling, in ambient temperatures under about 80 degrees F.”

So here’s my question to you @dbrn32, 1. Is this good? 2. Can I add fans to make them run even cooler?
My biggest goal here is to build a light that runs extremely cool, because I hate dealing with high temps in my tent. Last question for now lol 3. How does a MarsHydro 300w or the other cheaper LED fixtures cool their LEDs, I know they use fans like in computers, so I guess I’m asking for a comparison of the two. How cool will my COB with a heat sink run, compared to a “300W LED” with 2 computer fans? (I think this is more confusing than I’m trying to sound lol, so I’m sorry if you don’t understand!)



All good questions!

First things first, we spec’d your cobs to run at 2100ma (2.1 amps) if rapid isn’t confident that their sink will passively cool 75ish watts, that’s going to pose an issue. I thought I read somewhere that they did rate them for passive cooling to that level, but I’ll have to look. If not, we’ll have to look at 1 of 3 options. Finding a better cob/driver combo to run on their sinks. Finding a bigger heatsink. Or adding some active cooling.

As for the mars cooling, they add fans due to the lack of surface area of their heatsink. Going with a pin style Increases surface area enough to generally not need the assistance of a fan. The base thickness comes into play, but usually more of the fin size and amount of them are what’s important. Then when you enclose them in a case, evacuating the heat becomes more important.

Adding the fans will make the cobs run cooler, but won’t necessarily make your tent any cooler. You’ll just be removing the heat from your sink and spreading it into your tent. Make sense?


@ktreez420 it’s right here from their website. Not sure if what’s on the Web page or what the rep told you is more accurate. I would probably get more clarification before you made any hard decisions.

I think I have all the parts to build this fixture and check temps, unfortunately I’m a little short on time for the next week or 2. Perhaps you could surf around the Web and find some grow journals using this particular setup? I think it’s fairly common driver and cob combination, just not sure what everyone else is using for heatsinks.


Makes total sense @dbrn32! I will look around for some more info on the build, thanks again though dude!



Hey guys. I just got a quick question for @dbrn32
I just got my new led panal light i ordered off of ebay. 200 actual watts. I hooked it up an plugged it in. Works awesome. Strange thing is, i turned it off an noticed 1 of the red led diodes was still a little lit. Like its still getting a half amp of juice or something. Do u think its like a stand by light or do u think it has a short or something funky with the wireing? Heres a pic. Plugged in an then not plugged in. Or should i just send it back?