-Home page

Runs on free energy from the sun

Météo Samoêns

67m³ solar balloon seen from below


Mail Instagram Facebook YouTube

-Contact me
Rapporteur d'angle solaire Rapporteur d'angle solaire
Englishen Françaisfr

Solar angle protractor

(Metric system)
With its bubble level, note the angle that the sun makes in relation to the horizon.
Hold in your hand!

Mesure α

For a successful flight, it is useful to know the angle α that the sun makes with respect to the horizon, so that another flight can be reproduced under the same conditions, whatever the time of year. The rays of the sun cross the same layer of atmosphere in summer or in winter for the same angle α. This is an approximation, however sufficient for the solar balloon / solar hot air balloon activity.

Example northern hemisphere

Solstice d'hiver Equinoxes Solstice d'été
Image credits:https://energieplus-lesite.be


The basis for this measuring instrument is a schoolboy's protractor. A multitude of models exist, which is why I am not able to produce manufacturing plans. Below is the description for making a solar angle protractor from your own material.

Ensemble Niveau Azimuth Height
Angle protractor Ø120. Aluminum angle 20x20xepr.1. Aluminum plate 15xepr.2. Aluminum tube Ø6xepr.1. Threaded rod M3. M3 screws. M4 screw. Nuts. Washers. Cylindrical bubble level Ø15. Adjust the horizontal using the bubble level. Schematic diagram for height (α angle) and azimuth (β angle) adjustment.
Azimut Hauteur Azimut Hauteur Azimut Hauteur
Set the azimuth (β angle). The shadow of the vertical M3 threaded rod must merge with the longitudinal axis of the assembly. Record the height (α angle). Center the shadow of the horizontal M3 threaded rod on the Ø6 tube. Here, we can take an angle of 55° (July 6 - 10 a.m. UTC - latitude 46.7°N).


3D design Catia V5 Dassault Systèmes

-Read me Lisez-moi

Solar airship

3 solar balloons


1st human flight in history in 1783, by the Montgolfier brothers

© 2024 SBF -Legal notice