It's Time To Build A Grow Light

[Old Salt]

I've had most of the parts for a year, but life interferes upon occasion. So, now that life has settled down a little, It's time to transform these parts into something I can use.

Citizen CLU48-1216 COBs and Parts​

I started by laying out the frame, notching the angle aluminum, and drilling the holes required to mount everything. The ends and two center rails are 3/4" angle aluminum to provide stability, The outer rails are 3/4" x 1/8" bar stock. Mounts for the drivers are 1" x 1/4" bar stock, and the control/interconnect box mount is 1/8" sheet. These parts are also all aluminum. The hardest part of this stage is accurately drilling the holes for the pin heatsinks. I made a template for this, and drilled the holes in the angle and bar stock for each bank together. These holes are countersunk.

Laying out the Parts​

Next I welded the aluminum frame together. It wasn't difficult using a MAP torch and aluminum welding rods. I don't know why I was surprised, but it's like soldering. If you re-heat a weld it will separate, so if you want to weld both sides of the joint it must be done in a single operation. Then it was paint the frame; outside of course. I used an epoxy spray paint to seal it against corrosion.

The Frame Hanging out to Dry​

The control box has a steel base, and aluminum cover. I started with the base, laying out the holes, and cutting them out. My nibbler didn't work for the rectangular holes, so I used a jig saw.

Troubles with the Control/Interconnect Box​

Here you can see my design, and the current status:

• The cover is too large and needs to be re-made. That happened while bending it.
• The box was bent backwards, so the switch and control are reversed. I can live with that.
• The switch and power connector are re-cycled from a computer power supply.
• The circuit breaker is 10A about double what the light will draw.
• The black and green box is a power monitor.

The holes need a little work yet. I don’t have a large enough drill bit for the driver cord holes. The biggest I have is 9/16”. Canadian Tire has a step drill bit on sale, so rather than file away, I’m off to get one.

 

[mstraka919]

Awesome job. FYI on the reflectors. I removed mine and Timber stopped offering them with their lights. They were seeing losses in efficiency of 8-10% using the reflectors vs bare cobs. Also, they cause heat buildup at the cob surface. Light emits at a 130 degree angle from the cob surface vs 90 degrees with the reflectors so you are able to run the lights closer to the canopy and still achieve very even light spread. Good luck!

 

[Aroxol]

Nice work, OS - will be a great setup.

Also, I agree 100% on the reflectors. If anything I’ve read diffusion film supposedly helps LED distribution and is much more effective than reflectors (if necessary at all for wider angles).

 

[Old Salt]

I agree with leaving them off. I may install the mounts for them to provide limited protection for the COBs. I'll see when I get to that point.

I wish I had a PAR meter so I could map it out when complete. I'll just use one for Lumens, as I can's afford one this year.

 

[mstraka919]

I agree with leaving them off. I may install the mounts for them to provide limited protection for the COBs. I'll see when I get to that point.

I wish I had a PAR meter so I could map it out when complete. I'll just use one for Lumens, as I can's afford one this year.

There are a couple of places that rent them out for like 30-40 bucks per week on the web that I used when I was running reef systems. Problem is they are designed for underwater applications so I am not sure how well they would work for our current needs.

 

[Captain Cannabis]

Very nice work Old Salt! I like how the box turned out. I'm gonna keep an eye out for your results, in your next Journal. Hint....Hint!

 

[Strainyourbrain]

Gee golly me @Old Salt that is huge. Way outta my league for the time being. My DIY led's have to fit in a cupboard. Lol

 

[Old Salt]

Gee golly me @Old Salt that is huge. Way outta my league for the time being. My DIY led's have to fit in a cupboard. Lol

The COBs are on 30cm centers, so it will fit in my 60cm X 120cm (2' X 4') tent. The idea is to spread out the light so I can put it closer to the canopy.

 

[Old Salt]

Can you spot the error? The work-around is in place.

There's a Mistake Somewhere in There​

 

[SOG001]

Looks like a pretty clean set up, that light is gonna rock your world. I can't tell you how much I love my COB set up. I'm not familiar with your COBs I run Veros what spectrum are they?

 

[Old Salt]

3000K/ 80CRI

 

[SOG001]

I'm very interested in how well your light does as I am running mine at 1400mA and you are runnin yours at 1750mA. I can't imagine how much brighter the 1750 will be. How soon will you be using your new light?

 

[Old Salt]

I'm very interested in how well your light does as I am running mine at 1400mA and you are runnin yours at 1750mA. I can't imagine how much brighter the 1750 will be. How soon will you be using your new light?

Hopefully I'll have it in operation by the end of the week.

 

[mstraka919]

Whats the error did you not leave enough room for the control box with the cob's installed? I can't figure it out .

 

[Old Salt]

Look at the left hand driver. The mount is welded an inch closer to the side than it should be. I measured twice, both times from the wrong side of the bar stock mount.

 

[BobbyZ]

Hey I didn't realize you were building a light @Old Salt. I just built a QB light this weekend. Your frame is much nicer than my wood board... LOL! I'm running 4 288V1 QBs at 3000k. I'm pushing around 120watts per board. That's about the extent of my knowledge.

 

[mstraka919]

Ah I see. I used nuts/bolts and rivets for mine. I always wanted to learn to weld though

 

[Old Salt]

In my opinion this was more like soldering than welding. If you've ever soldered copper pipe you can do this. There's no flux involved. Simply clean the aluminum, clamp, heat, and apply the rod.

 

[Emilya Green]

Welcome to the build an LED club Old Salt! We can see how our new lights work soon in our next grows! I am going to do some FC/LUX measurements when I get these red/blue lights out of the way in my tent and try to get a better idea how I want to drive these lights. I am using the same driver as you, attempting to get around 70w out of the 100w chips. We are in uncharted territory now!

 

[Old Salt]

Welcome to the build an LED club Old Salt! We can see how our new lights work soon in our next grows! I am going to do some FC/LUX measurements when I get these red/blue lights out of the way in my tent and try to get a better idea how I want to drive these lights. I am using the same driver as you, attempting to get around 70w out of the 100w chips. We are in uncharted territory now!

I'm also designing a light hanger I think you'll like. There will only be one rope to adjust the height. Five pulleys will be required. A standard hanger will be used to pull the rope up from the bottom of the tent so that the control will remain at a constant height. The range of height adjustment will be the slightly less than width of the tent for me. This will be a summer project.