Ground Effect - FBL vs FB - HeliFreak
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Old 04-11-2016, 07:40 PM   #1
Roger Fowler
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Default Ground Effect - FBL vs FB

Here's a question - why can I hover my FB 450 right to the ground and land, but when I try the same thing with my FBL 450 it starts to drift off at about 2' above the ground. I just can't land without drift in some direction. Not a big deal - I just do an auto from 3' or so. But it does seem peculiar that the FB machine does not show any reaction to ground effect while my FBL machine does. I've been watching this for over a year and curiosity is finally getting the best of me.

Thanks in advance for any thoughts.

Roger
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Old 04-12-2016, 03:56 PM   #2
curmudgeon
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I would be interested in seeing a video of this phenomenon.
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Old 07-10-2016, 08:12 AM   #3
Felix the cat
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Quote:
Originally Posted by Roger Fowler View Post
Here's a question - why can I hover my FB 450 right to the ground and land, but when I try the same thing with my FBL 450 it starts to drift off at about 2' above the ground. I just can't land without drift in some direction. Not a big deal - I just do an auto from 3' or so. But it does seem peculiar that the FB machine does not show any reaction to ground effect while my FBL machine does. I've been watching this for over a year and curiosity is finally getting the best of me.

Thanks in advance for any thoughts.

Roger
FBL gyros auto-correct while flybars (obviously) do not - other than the flybar's effect on disc changes. FB's do not apply direct input to the servos.

When you're close to the ground, the rotorwash bounces against the disc somewhat affecting your pitch and/or roll ever so slightly, so the gyro tries to compensate and thus the "drifting / instability".

On FB there's only one "brain" working the inputs and responses. On FBL there's two.
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