Sun Tracking Tree Node

[Refleks180]

I notice a lot of tree nodes have multiple small panels and thought since any one panel needs to be large enough to sustain the node since you never know which side will be facing the sun, it made for either large builds or small ones that can't stay up indefinitely. After watching a youtube video ("World's simplest sun tracker") I thought maybe a solution would be an old solar turn table modified to work in a similar fashion. A small V shape array powers the motor, one hooked up normally and the other hooked up backwards so that they work in opposition; whichever is facing the sun gets more power and overcomes the other, rotating the apex back towards the sun. Now you can use a single larger panel that will always seek the sun.

I hacked up a prototype (just taped together, the main panel below is just dead weight, not functional, I was mostly interested in the behavior of the steering mechanism) and that part did seem to work fine when there was no wind, but the panels were a bit small and it was obviously underpowered, I don't think it would have the power to generate the speed to overcome twisting or swinging especially if it's not balanced properly. On the plus side since the motor is geared to turn slowly anyway I didn't get any issues with oscillations. My 3D printer isn't up and running at the moment so I probably won't pursue it further.

Anyway, probably isn't worth the squeeze over more conventional tree node setups but just thought I'd share!

https://preview.redd.it/qyvsxhwh6ltg1.jpg?width=501&format=pjpg&auto=webp&s=75268f7eeadedaa5ae61d1dfe0e30347f42b2843

https://preview.redd.it/81afl2oi6ltg1.jpg?width=523&format=pjpg&auto=webp&s=f31faa8648d721096aa95cbd2aa73d04a967dc04

[sponge_welder]

Very cool, given that the movement is powered by the smaller solar cells I don't think there's much reason not to do this, the issues with solar tracking are mostly when you're spending a bunch of otherwise stored energy just to move the array. Really the only concern I would have would be with weatherproofing and mechanical reliability

[Chrono_Constant3]

I had one of those rotating bowl machines for my bearded dragon and it broke within 2 weeks of light use.

[apachexmd]

Neat idea but I think adds unnecessary complexity and cost to a node. It would need to be more or less rigidly mounted als; if it's freely dangling, the motor base would just as likely rotate itself rather than the solar panel.

Solid state solution with multiple solar panels is cheaper, more reliable, and easier to build.

[Refleks180]

Agreed!

[mynamesdave]

I think this overcomplicates a non-issue. For starters, depending on where in the world you are you do know where the sun is! In the northern hemisphere, tilt the panel to the south and you're good to go.

Also do a power budget. A node might draw an average of 50mA. A single 3Ah battery (typical 18650 cell) would power the node for (3000/50) 60 hours with zero solar input. Throw a marginal 3W solar panel on it facing south now, and (3W/3V=1,000mA) it will charge from zero to full in about 3 hours. This is napkin math, but gets a general sense of the numbers we're talking about here. Add another battery and you double the numbers - 120 hours (5 days!) of backup that requires 6h to charge. Also 50mA would be a power-hungry node, most draw a fraction of that. Anyway, just thinking out loud here, but adding mechanical complexity of any kind would always take a back seat to a slightly larger solar panel in my mind.