I made the folding-arm tent-leg lamp mount:
It's made the same way as the
flexible top-mount fixture. (<<link) But, 1) it folds on the horizontal plane. And, 2) I added a "hand" at the end (where the socket mounts) to fold on the vertical plane.
I didn't use the plastic knobs because of the way this one folds. The top-mount fixture, it was hard to get the joints tight enough using wing-nuts. The lights could droop down. The plastic knobs were necessary to be able to crank that down more. But, the way this is horizontal, wing nuts should be good enough.
It's made the same way as the
tent-leg socket mounts (<<link, which you see one below the arm mount). But, it uses a 3/4" PVC "T" fitting. The "shoulder" of the folding arm fits in that snuggly (and then I secured it with a 3/16" diameter bolt through the PVC an wood).
The arms will fold together into a small package, with the socket retracted close to the tent leg. But, it's not as close as the clamp-on hardware mounted into the 3/4" PVC coupling (the tent-leg socket mount, which you see one beneath this folding arm mount). So, when a plant is full grown, I think I would use that original tent-leg mount for more clearance. (It would be cool to mount the clamp-on pivot piece into the PVC "T", and use the same tent-leg piece for both.).
When I make another one of these, I'd probably make it shorter. It extends further into the 2' deep tent. than it needs to. I would experiment with shorter segments for a shorter overall length.
The seedlings just sprouted Sunday evening, Monday morning. I'm testing Kellogg Palm & Cactus potting mix. It seems very well draining. 4-5 yeas ago I saw a bag of that torn open at the store, and thought "omg! that looks perfect." I've wanted to try it, but never got motivated. The seeds broke ground in just 3-3.5 days. That seemed like a good sign. I planted them directly in the soil (no soaking the seeds separately. No fine-peat seedling bed -- which I do with the soil I ususually use, because it seems too chunky for seeds).
They've stretched more than I like seedlings to do. I read that 100-300 ppfd is good for seedlings. And, 200-400. So, I started off at 130ppfd. That might not have been enough. These 4000k lightbulbs aren't as blue as they should be either. So, maybe it should be toward the 300-400ppfd range. Right now I've got it at 330ppfd. (I originally used a globeless lightbulb. I went low on PPFD because I was afraid that direct light might be too intense. I always use globed bulbs in reflectors for seedlings. I should have done that, and put it closer for more PPFD, but also diffuse.