6th Annual BLF Handmade Entry (Finished!) - gchart

Giveaways and Contests
22

OK, I get it now, the two power deliveries are wired parallel to the LEDs. Either just the 1mA source or that plus the 7135 will be on. :+1:

23

Yup!

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The PCBs came in today. At this point, I’ve got all of the parts except the LEDs.

Next up: preparing the housing (probably the most difficult step for me, limited access to proper tools)

25

Even though my 4000K LEDs aren’t in yet, I couldn’t help but build a prototype while I wait! I have some 5000K on hand, so I used those - I just wanted something warmer for a “lantern” style device.

Differences between this light engine and what I have envisioned for the final version:

  • 5000K LEDs instead of 4000K
  • Used a 1800 Ohm resistor instead of the 1mA current regulating diode. Assuming a supply voltage of 4.2V and a LED forward voltage of 2.43V (as measured), that should give me roughly 1mA on a full battery: (4.2V - 2.5V) / 1800 Ohms = 0.00098A = 0.98mA
  • Jumped the switch pads with a wire instead of a switch (like the CRD, I only bought one switch)
  • Stranded copper wire for the conductor pillars instead of the copper rods (only bought enough for the final version)
  • Battery is only held in place by the spring tension. I plan on having a partial copper surround and then a velcro strap or something to make sure it doesn’t budge.

Dim mode, Bright mode
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Action video:

Another tidbit… assuming a 3000 mAh battery, this should last 8.6 hours on high or 4.2 months on low/moonlight.

26

Nice progress. Is the battery going to be removable?

27

That’s pretty cool. You are certainly making some headway into the build.

28

Very nice!

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Very cool idea. The build looks like its coming along nicely.

30

Thanks all!

Yup, battery will be removable. It may not be super easy, but reasonable enough.

31

:+1:

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Rough cut of the housing, oak and part of a seasoning shaker:

33

That looks like it will be a nice looking lantern when you’re finished!

34

Thanks. I wish I had a band saw or scroll saw and perhaps a router, but alas… I’ll make do with my jig saw and some sanding.

35

Ok, I decided to go a different route for the end caps. I was trying to mostly use materials I already had sitting around (putting the B in BLF!), but that oak was hefty to work by hand.

So I picked up a piece of 1/4” poplar. I think I’m going with two stacked discs, one being smaller to fit into the plastic housing, large enough to pressure-fit in place. I’ll glue that to a slightly larger disc that will sit outside of the housing.

Here’s the rough cut with a jigsaw:

And getting to it’s final size & shape using my palm sander:

36

Those look nice. I don’t think I could get it that smooth with hand sanding. I’m not that patient. :person_facepalming:

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Thanks David. I spent over an hour sanding those things. Tedious!

38

Looking good! :slight_smile: I always like lantern custom builds.

39

Making rounds by hand is tedious at best. But those look good

40

Ok, all poly’d up (6? spray coats each side with some sanding in between). Nice and snug, solid feeling.

Still waiting on my 4000K LEDs. They must be taking the slow boat from China. Once they get here, I’ll have everything to build the final light engine.

With this much time left in the contest, I feel like I should do something more to up my game. Thoughts or ideas? Something that doesn’t involve redesigning the PCBs, that is

41
  1. Add a nice lanyard hole
  2. Add a threaded insert for tri-pod
  3. Change to RGB+W emitters and a nice driver with color ramping/mixing OOPS, didn’t see the part about not changing the PCBs
  4. Go back to the oak (that one will take up plenty of your time :stuck_out_tongue: )

EDIT: I need to say, though, the Poplar looks really nice. My suggestion to go back to oak was just so you could use more time.