My quad is equipped with T-Motor MN5008 KV400 motors mated to 17" Tarot propellers. Total weight of the aircraft including battery is 8.4 lb => 3810.2 gm. The T-Motor specs say that I Can expect 3982 gm thrust at 100% power using 17" propellers. This gives me a 4:2 thrust/weight ratio. Is this too excessive? I have found that I Cannot seem to hover as the throttle stick is below midpoint - the aircraft either climbs or descends. Any suggestions?
No such thing as excessive.
Not really, nothing unusual to see here. Post a link to a .bin log at hover.
If your weight is 3.8 kg, and max thrust is 4 kg, so you would have a ratio of 1:4, not 1:2, it is not excessive. In fact, it would be borderline on the downside, once you add to the equation discarged battery, wishful thinking of the manufacturer (although T - motors are ones of the best), not ideal props, and air density (unless you plan to hover at sea level), and most importantly extra power needed to fly around.
For my purposes, I aim for 20 % hover power at sea level and fully charged battery.
Okay, will do. Currently the weather is not conducive for test flights - winds are excessive. Perhaps I’ll get a chance in a day or two.
I am happy to report successful test flights. The winds abated which afforded an opportunity to take the quad out for a test. There were still some breezes from the south but I Set up anyway and waited for a calm spell. Takeoff was smooth with no wobble, and I immediately landed. I took off again, climbed a bit higher and was able to hover - no excessive vibrations and the motors seemed to be working in synch. Pitch, roll, yaw controls were fine and I landed manually without incident. A third flight afforded me the opportunity to test RTL which worked as well. Gusts from the south cause the aircraft to drift towards me but I Was able to counter via pitch control (aircraft was pointed in the wind). I flew with default param settings save for those regarding the arm switch and landing gear.
Above 8 will be a bit PITA as hover thrust learn won’t work.
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True, but I have a few craft below the learn threshold (.125) and it’s not a big problem to set it from a log and disable learning.