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Quantum Board PPFD Results
Posted: Sat Jun 24, 2017 5:13 pm
by LEDG
Re: Quantum Board PPFD Results
Posted: Sat Jun 24, 2017 5:47 pm
by Jolly Green Giant
awesome
just watched the video also... I love my 135 watt!!!!!!!!
Re: Quantum Board PPFD Results
Posted: Sun Jun 25, 2017 10:10 am
by majorana
Re: "Final thoughts" - how much did you spend on U-channel aluminum bars (aka heatsinks)? Here in Europe a 2 meter bar is like €3-5 at the hardware store. As for ease of mounting: how complicated is it already to wire these strips (a bunch in series, and bunches in parallel) and stick them on the aluminum bars?
That said, I too would be happy to get a ready-made kit and save myself the trouble of working out any details. Unfortunately I suspect the added/premium cost involved for a HLG kit -- especially when including shipping to Europe -- would add too much to the material cost (i.e., when comparing sourcing the parts individually).
My plan is to build a lighting fixture around the the Samsung LM561c diodes precisely because it seems simple, and that I can save on the heatsinks. The heatsinks I ordered for my Vero 29 fixture ended up being almost 40% of total price - both because they were expensive-ish and because of the added weight to the shipping.
I'm waiting out until September/October with hopes that better data would be available to demonstrate that the PPFD/lpw measurements also correspond to actual efficacy (grams per watt).
Re: Quantum Board PPFD Results
Posted: Sun Jun 25, 2017 7:03 pm
by LEDG
Well, I've got a good handle on how these things need to wire up in order to get the right current through each diode, but all the wire stripping and connecting was tedious.
I spent nearly $100 Canadian on all the aluminum channel and square tubing. That being said, I could have gotten it cheaper if I shopped around more and went to some metal shops, but I took the easy way out and got it at Home Depot.
I think there will be a ton of data on these things in the next few months as some of the serious growers get their hands on them and start posting results.
Re: Quantum Board PPFD Results
Posted: Tue Jun 27, 2017 8:51 am
by majorana
Me, having close to zero technical background and just as much hands-on experience, would benefit even more from any craftsmanship than can bought. My question is how much does it amount to.
I tried doing some back of the envelope calculations: Online I see that the 135W kit, aka QB288, costs at the Lighting Group $71 (on sale). That doesn't include the driver or heatsink ($12 on sale). At Digikey a 288 diode cut tape goes for $63, but that difference is small enough to justify having the diodes assembled and ready to wire.
However, going bulk the numbers shift: when multiplying 8 units of HLG's QB288 (for the ~1kW range) that would be $572, compared with $337 of diode tape at digikey. (I'm guessing a quote from an Alibaba seller can go even lower.) I'm making an educated guess that aluminum U-bars would cost half as much as the heatsinks, and save another $70 on shipping.
For some the labor cost involved would exceed this $350 gap, for others who enjoy more free time perhaps that money could be better used