Testing out a new prototype USB grow light, the uGrow2.0, I took an 11 day time lapse video of two hydroponic lettuce plants (growing in rockwool soaked with a nutrient solution) growing under the light. Play the video to watch lettuce leaves expand before your eyes like a balloon on a helium tank n...

Really interesting experiment here. It's cool how much power you can get out of an inexpensive supply. I will be interested to see how much light you can get out of it once you switch to some high-efficiency brand-name COBs, such as Bridgelux or CREE units. My experience with the cheap COBs from Ama...

I attended Light Fair International in Chicago last week and everyone there was saying out the letters "C.O.B." Now, we've always just said COB as one word because it's a lot easier. Please weigh in! What's the right way to say it?

[/quote] :oops: Someone needs to manufacture an aluminum clamp heat spreader big enough to hold the 200w COBs. The aluminum clamp design is awesome. Maybe someone with an aluminum extruder or machine shop will stumble upon this and start selling them! I had been considering something similar at one ...

LEDs: some of the most efficient lights available, but also very heat-sensitive. And as the power goes up, so does the heat. Most of the time, we solve this with lots of aluminum in the form a giant heat sink and, when things get even hotter, a big 12V brushless DC fan. But there are disadvantages t...

Took a look at the picture; looks great! I see that you have bolts through the 3 rails already, so you are probably right, you should be fine to glue the others. As far as thermal expansion and contraction goes, I guess as long as the adhesive is flexible enough when cured, it shouldn't be a problem...

With Bridgelux COBs, usually the letter in the part number indicates CRI, or color rendering index. Taking a brief look at the datasheet for the Vero 29, this seems to hold true. Unfortunately, Bridgelux didn't choose to include very comprehensive spectra on this datasheet, and none of the 90 CRI op...

I worry about adhesives, especially if you will put any force on the aluminum rails (like using them for hanging the lights). Also, when the LEDs turn on and off each day, the aluminum will expand and contract. Could crack your adhesive. So, my recommendation is use the screws for as many rails as y...