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• Boost converter & cable

  lion mclionhead • 7 days ago • 0 comments

  After many experiments, found the ideal battery cable route to be right under the hinge in front.  That allows it to fully collapse & keeps all the cables away from the paw.  The biggest problem was cables getting tangled in the paw. 
  

  https://www.amazon.com/dp/B089Y7NDCR

  Converted it to a dedicated buck converter, for no other reason that to save space, make it lighter & to fry a buck converter the usual way.  Note input + & - on these get covered by hot snotting the corners. 
  

  
  

  These are rated for 2A & the flashlight is putting .3A 16.7V out in the worst case.  The handle is still about the right size for the cables & a lion paw.
  

  It could use a lid over the electronicals.  The holes under the buck converter are problematic.  The PLA rivets have to be moved in to the new form factor.  The switch should go in the lid too.
  

• Attempt 3

  lion mclionhead • 06/17/2024 at 17:30 • 0 comments

  Another final design which ended up an incremental improvement.  It collapses the smallest of any of them.  It would collapse further if the hinge was right on the bottom, but this would interfere with the bits needed to stabilize the legs.

   It's rigid despite using panel legs.

  It stands on its end.  This requires unbolting the light.  The washer spreader really needs knurls.

  Another way to stand on its end while disassembled is less stable.
  

  Tongue & latch design attaches the panels at right angles without tools.
  

  Switch is a real pain to install, even with the tool.  It might be smarter to stick it out the side.  It's not ideal to have the battery cable going down the handle instead of sideways. It might actually be best to go up & over the side.  These are really minor details.
  

  The switch tool gets just enough grip to tighten the nut but isn't as easy to use as hoped

  Disappointing to have all the locking mechanisms exposed on the bottom & prone to getting knocked loose.  As usual, the ugliest panel design is the most practical.
  

  Maybe the battery tray could carry other junk.
  

  Comparison with other light sources.
  

• Attempt 2

  lion mclionhead • 06/15/2024 at 23:29 • 0 comments

  Attempt 2 got a lot right.  1 trick is installing the switch requires a custom tool: wrench.FCStd

  It burns 4W when it's cold, rising to 5W when the LEDs warm up.
  

  Making the handle short enough to fit in the battery tray required making it harder to fit the battery in the sides, but it does fit in the front & back. 
  

  There is still a desire to turn the legs into 2D panels which fold completely flat.  The mane challenge is it requires the battery tray to get a hair longer & become a trapezoid.  The battery would only fit in the sides & it would wobble a lot more.  It would be worth millions in rent.

  Another desire is to stand it on its rear end, so the back needs to be flat.
  

• Attempt 1

  lion mclionhead • 06/14/2024 at 21:01 • 0 comments

  It took years to come up with something that met the requirements on paper.  The leading idea eventually became clamp on legs with a bathtub for the battery.  The 1st printout instantly revealed the problems.  The clamps instantly came loose with any tugging, although the 8 were redundant enough to keep it together.  It was not possible to undo the clamps near the switch without a tool.  The battery didn't fit through the front & back.  It had to go in the sides.  The clamps had to bend too much to get in.  They might require a .4 nozzle to be sharp enough to not need such a depth.  They could also be longer.
  

  The clamps should be built into the bathtubs & grab in front & behind the legs.  They would be more assertive & wouldn't need to be separate parts.  The 1st prototype might still work in a pinch.

  If the diagonal legs were straight or curved, the battery could go through the front & back.
  

  Storage was manely impacted by the clamps sticking up.  Z seam placement is killing the legs.
  

  If the top bathtub was slightly shorter, it could be stored inside the bottom bathtub.  A tweak to the rear legs could make the top shorter.

  The holes in the sides made it hard to get the clamps on.  The area where the clamps slide has to be flat & needs some kind of guide.  It can be thinner.
  

  The quest began for a low voltage cutoff.  They all currently require building a discrete circuit.  There's no single chip solution for 10V or 6.7V.  The MCP120 was a TO-92 cutoff for 5V only.  The search term is supervisor.  It's going to be easier to have an unregulated pilot light show the charge level, since the mane light is constant brightness.
  

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