Brightening my DayLilies

April was a tricky month. Formlabs is bustling; we announced a big new product to the world and now the days are spent on the final tweaks to get it into our customer’s hands. And what is my role in all of this? I am, well, focused on growing some vegetables in our still-too-short New England daylight.

A co-worker was tossing this LED growlight array – a decent number of the diodes were out on the left half , and the entire right half was dark

Silly comparisons aside, my work is quite disconnected from the big project that is now so thoroughly in the spotlight – I’m quite busy on Fuse, our beautiful freak of a machine, and I’m quite excited to someday share what I’ve been working on! But despite reality being the contrary – it has felt a bit like the world is passing me by. Getting past that notion isn’t easy, and recent happenings in life have lead me down a path lately of not knowing what is in store for the future. Some people turn to the wilderness, or go on big, expensive adventures to find a purpose (which I guess you could say I did last summer…), but I needed to find something a bit more local this spring to take my mind off these thoughts.

How not to remove 1W plastic encapsulated LEDs. I determined the bank that was entirely out was due to a led/backup Diode pair that had both failed. Either way, replacing some of the diodes was in order. Some online sources lead me to believe that these packages could handle 260C, but even with preheating, that didn’t manage to melt the solder used on this board. Higher temperatures lead to what you see here. They must bake these at a very precise temperature to flow the solder, but I don’t have that sort of patience for figuring that out…

Gardening is a great hobby turn to in moments like this – it’s both productive, relaxing, and time consuming. The trifecta of distraction! It’s also a soft spot for me – my late mom was prolific in her vegetable garden, and my memories of hiding in the cool, sweet-smelling corners of the sprawling patch in our front yard during the summer – filled with gigantic tomato vines, bean trellises, and sunflowers have always stuck with me. I won’t wax too poetic and claim to be carrying the torch or anything like that – but I can’t deny there is some feeling of connection there.

The technique I found worked best for the removal of dead LEDs involved cracking off the plastic housing, and blasting the thermal pad with a blunt Iron. To re-install, I applied a dab of solder paste to the thermal pad on the PCB, and soldered the two leads with the same iron. I was unable to reflow the solder paste, so either it will be conductive enough in its current form, it will get hot enough from the LED to reflow into place, or the LEDs will burn out and I’ll go back to where I started! 🤷‍♂️

I attempted to start some vegetables last in 2017, when I hid a few pots and trays in an unused stairwell of the building on campus where I worked (In hindsight, better documenting that would have been a good idea…). It definitely took up more of my time than a hobby should have, but it also gave me a routine, which I found helpful in keeping the ball rolling in the few chaotic months leading to my graduation. Starting from scratch is very rewarding – not only do you save a significant amount of money by growing from seed, but the feeling of seeing something increase in size by several orders of magnitude from nothing more than a bit of water, light, and various chemicals is pretty incredible. Maybe that’s what it feels like to be a parent? Probably not quite the same, but it is pretty easy to fall into the trap of calling the newly sprouted seeds the babies.

We’re in business! let’s grow some seedlings under here!

I missed one LED, and definitely missed on the color temperature. That was actually intentional – the Phosphors in cool white LEDs absorb/re-emit less of the blue light emitting from the chip, and there is an inherent power loss involved in that change in frequency. This means that for a given electrical power in (which is true here, since the LED bank is driven by a constant current of ~540mA), cool white LEDs in theory put out a bit more light, or at least generate less heat per unit light output ( I think). Also, the cool whites were cheaper. So maybe I am just trying to justify my frugality..

This year, I might not have the similar levels of stress, and I’ll admit my life is a lot more predictable now than when I was on the cusp of entering the adult world. But I do think a routine, on top of the daily tasks of the office, is a good thing for me right now. Hopefully now that I am armed with more disposable income, a bit more time in the evenings, and some friends with similarly-colored thumbs, the fruits – or tubers, or whatever of the labor will be a bit greater!

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