Showing posts from February, 2013

More propeller tests

Recently, I discovered some small counter-rotating propellers that I didn't know before. I ordered some and did some tests. The red 4x4.5" props look really good, nice thin airfoils and a good precision. During the tests, they made the least amount of noise, and are currently my preferred ones. The performance of the 4x2.5" props is even better, but they have a pretty terrible sound and seem to be less balanced. Both propellers outperform the AirAce propellers, but this is not really a surprise because the AirAce have a smaller diameter and more blades. What is also interesting is the weight of the propellers. A propeller with a lower weight potentially has a lower moment of inertia which is beneficial for the control loops: AirAce: 2.1 g 4x2.5": 1.5 g 4x4.5" : 1.3 g So this is an advantage for the 4x4.5" propellers, especially because the weight of this propeller is more concentrated to the center, which should further lower the momentof inertia.

GEMiNi, frame + canopy

Here are two images of the current status. Green is the favorite colour of my girlfriend ;-) . There will soon be an additional one in purple I fear...

GEMïNï progress...

I just realized, that I haven't yet posted an image of the PCB that I am using since half a year in the BOLT S|2 and soon in the GEMiNi. It is really small and weighs around 1 gram. It contains the minimum number of parts possible + 3 LEDs: Thermoforming the canopy also worked pretty well once I found the correct temperature. I tried Vivak (PET-G) and black Polystyrol: The chassis should be finished very soon, I am really looking forward to putting everything together...!