Part 2: Driver “Prototyping” (12/21/2019)
Sorry chaps! I haven’t had that much time on my hands as I’ve been waiting for parts.
I’ve come to the decision that since my circuit outlined above was basically a slight modification of a manufacturer’s recommended setup for their 2218 3v voltage regulator chip, I’d just buy one of those tiny factory implemented 3v boost circuits and go from there, as buying the parts to make the boost section would have cost me $25+shipping with a ton of capacitors and resistors left over since you can’t really buy what you need in small quantities, and if you did, shipping wouldn’t really be worth it. All I needed to do now was throw a resistor on the end of the circuit to regulate the current as voltage would be constant until battery voltage dropped too low. Also, this factory implementation is fairly efficient, so I wouldn’t have to go mucking around improving efficiency. I intended this light to be relatively practical, not just an exercise in manufacturing via blood (I’m clumsy).
Here’s my trusty old bread board testing out a 5v boost driver and 100 ohm resistor on one of rngwn’s 2300k 5mm LED’s This limits the current to 21.9 mA +/- 0.1mA with the resistor dissipating 38 mW.
You might be wondering why the hell I’m using a 5V boost circuit after saying I was going to use 3V? Wouldn’t that mess with my efficiency? Answer: Yes, it would definitely decrease efficiency as the resistor would need to dissipate more energy. However, when my LED’s arrived, I didn’t yet have a 3V boost driver, and as of this point, still do not although a pack of 8 is on the way. I still wanted to test the LED’s and didn’t have anything else. After trying both the 3400k and 2300k 95+ CRI LED’s, I found the 3400k to be too cool a color temperature for the lantern’s intended use and settled on the beautiful 2300k. Honestly, I might just buy a huge pack from rngwn because I love these little warm LED’s so much. I need to get more so that I’ll never run out and stuff them into everything. :D.
Part 3.1: Wood Selection and Layering
Tools to be used
After mulling over it for a bit, I decided to settle on poplar for my wood of choice for this build. If you’re wondering if that is a bit at odds with my intent to use a darker wood, you’d be correct. There were a few things that factored into this choice.
- If I wanted the wood to be darker, I could just stain it before finishing
- I’m particularly cheap and this 3.5” x 48” x 0.25” piece only cost me $3 from the local Home Depot.
- Poplar is in that happy medium between hardwoods and softwoods. Although it is classified as a hard wood, it is much easier to work with than say something like Maple. As a hardwood, it has a very fine grain which would make for a nice smooth finish.
I took the board and cut six pieces of 3.5” x 1.5” x 0.25” to glue together in order to make a layered stock. Titebond Original Wood Glue was used as it is one of my two personal preference for wood glues, the other one being Elmer’s wood glue which I didn’t have on hand at the time.
Clamped together using 1.5” Hazard Fraught (Harbor Freight) plastic clamps.
It was as even as I could get it, but it looked like it could use quite a bit of sanding
Here we go with the sanding. 80 Grit 3M Sandblaster Pro! That sandpaper is great. It’s well worth the extra buck or two for a much better sanding experience compared to every other sandpaper I’ve ever used.
… Three Hours Later
Time to square off those ends with a Stanley saw and a cutting jig. You’ll also see the diffuser I intend to use, although in its base state. It’s a high quality Carlisle 1.5 oz. plastic shot glass that I’m going to chemically “frost” with paint thinner. Cheap and durable, though I had to buy it it in a pack of 24. Good thing I don’t intend for this lantern to be a one-off.
That’s all for now folks! I intend to round out the square body and make the fittings to hold the light diffuser/shot glass to the body. Also, a flared base might be in order! It might be a while before I find more time to work on this, but I promise I’ll update as soon as the next phase is complete.