@dbrn32 - what would you think about me putting the new rail in the middle of the tent and moving the existing panels further to the left and right?
I’m trying to determine the best way for me to use the new rail. I believe I’ll be able to run the new rail a lot closer than I can run the King Pros, so I was thinking it might be best to put it in the center, parallel to the current lights, and run it down closer to the canopy.
I also considered putting it on the front or back perpendicular to the SCROGs. What do you think is the best way to get as even a light field as possible?
I think I answered my own question by modeling the two scenarios. Based on the length/width of the existing fixtures, I think it’s best to put the rail perpendicular to the SCROGs on the back or front of the tent. If I have a 42" bar in the 48" in space, that will leave 6" from the wall to the end of the bar. If I mount one COB on the center, and one on each end centered at 10" from the wall (4" from the end of the 42" bar), that should leave somewhere around 17" from center to center. So I would split the difference with the remaining two COBs, and end up with them spaced at 8.5" apart from center to center. Or I could do it in 8" increments across the whole rail (with the ends being 8" from the walls).
Where will the driver go?
With my drawing it doesn’t look like there is a lot of room for the driver, but I’ll get a better idea once I have the angle tonight and can play around with it.
However you feel it’s going to work best is probably the right answer. You’re there looking at it, and you seem to have a pretty good grasp of what to look for. There’s not going to be a big difference in 8 or 8.5 inch spacing on cob centers, so again go with what you think. You can always see how it does on this run and tune it for the next one.
You do bring a good thought, putting it into the middle. This bar is going to blow the other lights away in par levels, if your canopy is the most dense in the middle you may benefit more running it there. But don’t mistake lack of heat for less power. You’re just making light more efficiently therefore creating less heat.
I usually remote most of my drivers for that reason. Install it off to the side somewhere and run a couple of extra feet of wire. Depending on how you plan to hang the light, you can mount driver to the outside rail of the frame on its side. But it will throw balance off quite a bit, which will require a fairly rigid mount to offset the balance.
Yeah, I think for now I am going to run the driver remotely, and when I get to building the full system I will look at mounting them to the substrate. At that point I might also look into consolidating to a different driver, but that’s way down the road. For now the best thing to do is keep my options open. Looking at the tent, I think the way to go eventually is four rails of 5 COBs each. With 3 rails I don’t think I’d get as consistent of a light field across the whole space. Perhaps going with four rails of 4 would be ideal…
Three is probably fine, most are going to consider 12 50 watt cobs done. 15 40 watt cobs is even better coverage. 20 40 watt cobs is going to be more than you need. But if you went that route, you could dim them and say run them at 25-30 Watts and take advantage of efficiency boost. More cobs and better coverage will just require them to put out less light.
You left out 16 at 40w. Since the tent is square and I pretty much use all of the square footage for the plant, I think 4x4 makes sense. Then I can space them the same distance each way for a nice, even field. That makes sense to my pea brain.
It does, but you’re underestimating the condensed light from already having rows of 5. I’m just going forward with the thought of you building identical bars. Three 200 watt bars is enough for a 4x4. Three 70 watt cobs, 4 50 watt cobs, 5 40 watt cobs. More cobs at lower current power gives you better coverage, but you don’t need to get ridiculous with it. You’re already better than most with bars of 5 cobs. That was kind of built into taking advantage of the deal on 1212’s.
Maybe there will be a better deal on something else when the time comes. So I wouldn’t get too far ahead of yourself. The more condensed the light overlay is the higher the par levels will be. So you could even do like 4 50 watt cobs in the middle, and then two bars of 5 40 watt cobs on the outside.
Now I need to do some wire management and put some holes in the frame to hang it - I missed that step when I was drilling earlier.
But all in all this was an easy project! Especially for a guy who had to use a hacksaw to cut the aluminum and a lighter to shrink the heat shrink sleeves. I have to say it was fun to break out the soldering iron. I don’t think I’ve soldered anything since electronics class in high school. Good to see I still remembered how to do it.
Looks good! Personally, I run all my wire inside of frame. Easiest thing I’ve found for wire management is the peel and stick wire tie or zip tie holders. Home improvement store or hardware store should have them. I can find pic if you’re not sure what I’m talking about. But you just wipe the frame with some alcohol and they stick good. Then you can put wire tie through and bundle all of your wiring wherever you put one.
I didn’t take a pic of it (I just finished it) but that’s what I did. I took the wires from the leads on the COBs back around to the inside of the frame and used a peel and stick zip tie holder and a small zip tie. I did the same thing on the return wire (the long one) from the end of the rail back to the driver. I may end up lengthening the input and output wires to get the driver a longer leash - I just wanted to make sure it worked so I quickly soldered it together.
I was going to use some of those fancy connectors but I figured if I could solder stuff in 7th grade I should be able to do it now. My lights are off until 7:30am, so I’ll try and get this hung tomorrow morning.
EDIT
I think I understand better what you mean - instead of taking the wire from the COB around the outside of the frame like I did, you go under the frame from the COB? I was trying to avoid having anything touching the heatsinks…
It’s ok for wires to touch the heat sinks. They don’t get super hot. Nice job @Bogleg the fixture looks great. I need to get my rear in gear and do another one of these! After that little DIY project, your over that blurple lights just like I am!
Yep I agree with @Covertgrower. If you want to be extra sure, you can check the temp rating of your wire, should be like 90c. Running at that current with that size heatsink I’d be surprised if they hit 45c.
Assuming you went with solid wire, it should have a little bit of bend memory in it. So if you wanted to be extra extra careful, you can just leave the wire length long enough that with the natural bend in it, it doesn’t physically touch the heatsink. Either way, I think you’ll be good. The rapid heatsink has holes built in it for wire routing, and I’ve weaved them around the pins with 75 watt cobs without issue.
I will say that if you plan to use those holes, be careful as to not skin any of the wires. I’ve done that once. Was more out of my own carelessness than anything. But they are forged, and there can be some sharp edges.
To add to what @dbrn32 stated about the holes for wire. What I did was push them through, and put a 90° bend in the wire lining it up with the push in connector. They can be sharp. Yes. @Bogleg
