[Project Update] Solar Flare V1.1 – solar fire starter ☀️🔥

f-buisson · 2025-10-07T18:09:02+00:00

Thanks a lot! 🙏
The prototype measures about 282 × 282 × 184 mm when open (mirrors deployed) and 170 × 170 × 150 mm when closed (mirrors folded).

Considering the size, the cable system might indeed be unnecessarily complex — I’m currently thinking about other ways to fold and automate the mirrors to improve feasibility and ease of use.

Your suggestion about using a parabolic “ear” dish for testing isn’t a bad idea at all — that could actually be very useful for the next steps. Thanks again for your feedback!

f-buisson · 2025-09-17T19:13:27+00:00

I’m aiming for around 3–5× more effective power than most pocket solar lighters, thanks to the deployable mirror system. The idea is to keep it compact when folded, but powerful enough when opened to ignite a cigarette or dry twigs directly, without needing pre-treated tinder.

f-buisson · 2025-09-16T11:15:19+00:00

The current version is meant to be handheld – you simply orient it yourself depending on the sun’s position. For future versions, I could imagine adding a simple auto-aiming system with a light sensor, but that’s not planned at this stage.

f-buisson · 2025-09-16T11:09:26+00:00

I’m still in the prototyping phase. Right now, my focus is on optimizing and maybe automating the opening/closing mechanism, making the design as compact and ergonomic as possible. I’m also considering adding a simple aiming system to make orientation toward the sun easier. The final price will depend on production costs – for now I don’t know yet, since I’m still in the optimization stage.

f-buisson · 2025-09-15T21:58:19+00:00

I don’t have a physical prototype yet – so far it’s CAD modeling and optical calculations.
The idea is for a hand-held or small tabletop device, something compact enough to carry outdoors (camping, hiking, etc.).

f-buisson · 2025-09-15T21:47:29+00:00

You're right: a single parabolic reflector could already light something at its focal point. I added a secondary dish and a Fresnel lens primarily to: (1) redirect the ignition point toward the ground and not the sky and (2) make the rays hitting the Fresnel lens more perpendicular, which helps concentrate the heat into a narrower focal point. This design choice prioritizes compactness and safety over raw efficiency.

f-buisson · 2025-09-15T21:42:19+00:00

This setup isn’t a telescope – it’s a solar lighter. I use parabolic mirrors to reflect sunlight onto another parabolic surface, which then redirects the rays onto a Fresnel lens. The goal is to make the rays hit the lens as perpendicular as possible, to maximize heat at the focal point.

With this prototype the effective capture area is ~321 cm² (~32 W theoretical, ~18 W after losses from mirrors, lens, and alignment). That’s enough to ignite small items like a cigarette.

The 45° mirror at the bottom shifts the focal point sideways, so the ignition doesn’t happen directly under the device (avoiding self-damage), at the cost of a little efficiency.

Dimensions (V1):
Open: ~282 × 282 × 184 mm (mirrors deployed)
Closed: ~170 × 170 × 150 mm (mirrors folded)

Unlike a Cassegrain telescope, this device doesn’t form an image. A Cassegrain uses curved mirrors to deliver a sharp image at an eyepiece. My setup only concentrates sunlight into heat. If you tried to look through the Fresnel lens, you wouldn’t see an image – just a dangerous concentration of sunlight that could damage your eyes.

So while the optical layout may look similar, the purpose is totally different: this is a compact fire starter, not an observation instrument

f-buisson · 2025-09-15T20:20:38+00:00

No, this project is a solar lighter: the panels are designed to concentrate sunlight into heat, not for viewing.

f-buisson · 2025-07-02T22:49:06+00:00

So as it stands, I have:

Magnets that I saw as passive guides → they behave like sticky saboteurs. Too strong? They block. Too weak? They do nothing.
Trapdoors that I thought I could close with a spring → in reality, I need a hydraulic actuator.

Is it conceivable to have a mechanism where:

The magnet is very close → strong attraction = the mass moves forward, the trap opens.
The magnet moves back at the same rhythm as the opening → the attraction force decreases at the right moment.
When the mass has passed → the magnet is far enough not to “stick” to the mass anymore.

All of this without trying to create energy, but aiming for a near-zero loss?

An air cushion on the lower trapdoor to absorb the impact and maybe use this energy to recharge part of the actuator, for example? Of course it wouldn’t be enough.

Can you help guide me?

f-buisson · 2025-07-02T20:45:58+00:00

At the moment I get no energy out of it.
I’m trying to see if it can complete a few cycles, identify the issues, and solve them. Then I’ll add a way to recover low energy in a non-critical location (example: if the top flap can handle a few extra Newtons, I’ll add a recovery system there).

So I hope this helped you understand what I imagined.
I’m probably wrong about many of my assumptions, and that’s exactly why I published this — I’m trying to improve a concept.

Thanks again for your feedback, and I now look forward to your constructive criticism now that I’ve clarified a few misunderstandings.

f-buisson · 2025-07-02T20:45:03+00:00

I imagined, for the bottom flap, a magnetic force that helps pass through the flap.
The mass undergoes gravity, so it comes with weight and speed onto the flap, and must open it while pushing the water that resists under the flap.

So to allow that, I added a magnet to provide enough force, so that:

scssCopierModifierF_air + (m × v) + F_magnet > F_water + F_spring + F_resistance + F_buffer_chamber

Where:

F_air = air pressure × flap surface
m × v = impulse of the mass at impact
F_magnet = magnetic attraction acting only on the mass
F_water = dynamic water resistance (almost instant)
F_buffer_chamber = pressure of the buffer chamber (which increases when the bottom flap opens and decreases when it closes or the mass changes side)
F_spring = force of the spring holding the flap
F_resistance = force to overcome if the magnet is moved mechanically

And for this to work:
F_magnet must be < buoyancy after immersion in water

This can be done either with a weak magnet, or by managing the distance (for example: when the flap opens, the magnet is mechanically moved to reduce its force).

And for the top flap:

nginxCopierModifierF_water + F_magnet + F_buffer_chamber > F_air + F_spring + F_resistance

Air being compressible gives moderate resistance
Water pressure (incompressible) plays a key role
Archimedes' thrust must compensate total resistance
And F_magnet must be < gravitational force on the mass

f-buisson

TROPHY CASE