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Showing posts from February, 2013

More propeller tests

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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 g4x2.5": 1.5 g4x4.5": 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.

The differe…

GEMiNi, frame + canopy

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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...

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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...!