Final thread, promise. Any changes I need to make before I buy?

[HandyGringo]

I'm going to be building a LED for a 2x2 grow tent. That's 60x60cm.

I'm going to be building something like this 3x3 setup by Growmau5:

Driver: HLG-240H-C1400A (Up for debate, running 5 cobs at 1400 mA seems like a lot for a 2x2 space, maybe 1050 would be better? - Also I picked the A model because I don't want an external dimmer, but one on the driver. Sounds right?)

Cobs: 5x CXB350 3500k 36v the N0HCD35G model (Also up for debate)

The distance between the cobs will be roughly 10 inches/25cm, so the aluminium framing will be around 20 inches long and wide. For a 2x2 grow tent.

Any critique or suggestions before I go ahead? I'm not going to be buying from mouser by the way. The prices are insane.

The thing I'd like opinions on the most is the driver. 1400mA on 5 cobs for 2x2. Is it overkill?

 

[Rahz]

5 at 1400ma would be extreme overkill.

Even 5 at 1050ma will be extreme, but maybe not overkill. You can always dim.

 

[HandyGringo]

5 at 1400ma would be extreme overkill.

Even 5 at 1050ma will be extreme, but maybe not overkill. You can always dim.

I have no idea how the dimming feature works. I assume it just lowers the amount of mA? So if I get the HLG240H-C1050A, I will be able to lower it how much?

And the only reason I want 5 cobs over 4 is that I don't think I can cover a 2x2 feet area properly with 4 cobs, at least not while keeping it a pretty simple build.

 

[CobKits]

sure yo can. better with 4 than with 5 in fact.

do 4 x 1050ma for that space its plenty

 

[HandyGringo]

sure yo can. better with 4 than with 5 in fact.

do 4 x 1050ma for that space its plenty

There won't be a "coldspot" in the middle if I go with a X shape like the one Growmau5 made?

 

[CobKits]

its a 2x2 tent. your plants will need to be 12-16" away from the lights anyway, it will be fine

 

[Airwalker16]

There won't be a "coldspot" in the middle if I go with a X shape like the one Growmau5 made?

No. I told you dude. If you wanna do 5, do a pentagonal shape.

 

[HandyGringo]

No. I told you dude. If you wanna do 5, do a pentagonal shape.

I don't trust the pentagonal shape. I want uniformity, if that makes any sense. :/ It would bug me

its a 2x2 tent. your plants will need to be 12-16" away from the lights anyway, it will be fine

Thanks a lot! 1050mA it is! Do you happen to know how much you can dim? like from 1050mA down to what?

 

[grouch]

I agree that four would be plenty for a 2x2 but maybe rotate the frame so that the cobs are closer to the corners.

 

[Desmond J]

I agree that four would be plenty for a 2x2 but maybe rotate the frame so that the cobs are closer to the corners.

That.

 

[HandyGringo]

I agree that four would be plenty for a 2x2 but maybe rotate the frame so that the cobs are closer to the corners.

That.

Oh yeah, right! No idea why I didn't consider that. Good call.

 

[Airwalker16]

A pentagon would be very uniform..

 

[HandyGringo]

A pentagon would be very uniform..

I don't feel like it would. If you put it in a square space it's not going to be even everywhere imo.

 

[Airwalker16]

I don't feel like it would. If you put it in a square space it's not going to be even everywhere imo.

Give me another option with 5 that'll do better.

 

[sixstring2112]

I would not do a pentagon, stick to your original plan.that growmau5 vid is as simple a frame you will find and is easy to scale up or down. Fyi you can run 5 x 3590 cree cobs off of a meanwell 185-1050ma.you dont need to use the 240 series. And the dimming will be perfect for your setup.if you have decent height clearances you can run your cobs up higher and that 2 x 2 will be evenly covered in light,awesome sauce

 

[PhotonFUD]

Give me another option with 5 that'll do better.

Get a PAR meter and adjusting on the fly

 

[Rahz]

I have no idea how the dimming feature works. I assume it just lowers the amount of mA? So if I get the HLG240H-C1050A, I will be able to lower it how much?

And the only reason I want 5 cobs over 4 is that I don't think I can cover a 2x2 feet area properly with 4 cobs, at least not while keeping it a pretty simple build.

You can fit 5 on a HLG-185H-C1050

4 will be a better fit for a 2x2 square, plus the PPFD will still be just over 1000 so I would consider ditching the extra cob. 4 will fit on a HLG-120H-C1050 so you can save a few bucks there as well.

Dimming does alter the current, and if you're vegging in there it will be a good idea to have some dimming. The A version can be dimmed to 50% with a screw driver. The B version can be hooked to a resistor on a switch for a set dimming function or a potentiometer and will go down to 10%.

 

[Airwalker16]

You can fit 5 on a HLG-185H-C1050

4 will be a better fit for a 2x2 square, plus the PPFD will still be just over 1000 so I would consider ditching the extra cob. 4 will fit on a HLG-120H-C1050 so you can save a few bucks there as well.

Dimming does alter the current, and if you're vegging in there it will be a good idea to have some dimming. The A version can be dimmed to 50% with a screw driver. The B version can be hooked to a resistor on a switch for a set dimming function or a potentiometer and will go down to 10%.

View attachment 3790017

LOVE THE NEW AVATAR @Rahz

 

[HandyGringo]

Give me another option with 5 that'll do better.

I'm not saying I know something better, but it's not very uniform.

You can fit 5 on a HLG-185H-C1050

4 will be a better fit for a 2x2 square, plus the PPFD will still be just over 1000 so I would consider ditching the extra cob. 4 will fit on a HLG-120H-C1050 so you can save a few bucks there as well.

Dimming does alter the current, and if you're vegging in there it will be a good idea to have some dimming. The A version can be dimmed to 50% with a screw driver. The B version can be hooked to a resistor on a switch for a set dimming function or a potentiometer and will go down to 10%.

View attachment 3790017

I'm going to do exactly that. Thanks a lot for your input. I'm going to go with the B version. Adding a knob isn't that big of a hassle, and being able to dim that much is really a nice feature for veg and seedlings.

Thanks a lot!

 

[jeepster1993]

I built an X.
50 watts per cob in a 2 x 2.5 tent, so a square foot larger.
This is an HLG 240/1400 driver and Cree cobs, with a dimmer. I keep the light 2 feet from the plants and only run it at full power during flower. It will cook the plants if I let it...
This tent will grow it like crazy.