Confused !!! :(

[joe.lel]

Took the Rappy out or its maden flight today!!

Very twitchy, dialed in 30% expo on the control surfaces and all is a lot better (probably do with a bit more).

The problem i am having is with the Gy401 Gyro.

The tail was not particularly solid, drifting left.

So come home to read through the GY manual, which says that when the light is solid on the gyro it is in AVCS mode (Head Holding)??.

The problem with this is that, the AVCS light only comes on when the Gyro setting is LOWER than 48%, and according to another site i have read that anything lower than 50% is rate mode!!!!.

Dont understand at all. Please help.

Cheers

Joe

[Andy from Sandy]

Gain channel reversed.

If you are using a number range of 0 to 100 only then 50% is the cross over so 49% = 2% gain, 48% = 4% gain, etc Going above 50% is similar. 51% = 2% gain, 52%= 4% gain, etc.

Don't worry about which side of 50% is HH just go with what works or try reversing the gain channel and see if that puts it as described on the other site.

Most TXs have a gyro menu and show gain as 0 to 100 for HH and rate mode which then matches the gyro.

[snapshot]

Different radios put out the signals in different ways, it could be the servo reversing has ben changed etc. Futaba's and JR's expo rates work in opposite directions etc. All radios are different, thats the reason the gyro's have indicator lights to let you know which mode they are in. They all vary and hh mode could be 0-50%, 50%-100%, 0--50%, -50%- -100% or even 0-100%. It's just set it so that the light comes on and take it from there.

[joe.lel]

Its a Spektrum DX6i, Its wierd, as the Blade 400 has a GP750 gyro in it and the Gyro is set at 63.5% LOL.

[liambaker996]

hope what we told you works joe

[Steve]

With most gyros, the middle value of the Tx output range is zero percent gain. When you go above the middle value, you increase the gain in say heading hold mode, and when you go below the middle value, you increase the gain in rate mode.

Some Txs use a range of -100 to +100, which means zero is in the middle, one gyro mode is positive values, and the other mode is negative values.

Other Txs (sounds like yours) use a range of zero to 100, so 50 is now the middle value. Now, heading hold mode raises from 50 to 100, and rate mode raises from 50 down to zero.

Which side of the middle point is heading hold and which side is rate mode are not set it stone - they can be either way around, but like you say for the 401, when the light i son solid then you are in HH mode and when it's off you're in rate mode.

The pic should help.

[Steve]

Its a Spektrum DX6i, Its wierd, as the Blade 400 has a GP750 gyro in it and the Gyro is set at 63.5% LOL.

63.5% isn't 63.5%!

It's (63.5 - 50) x 2 = 27%

i.e. it's 27% of the way between 50 and 100

The equivalent rate mode value would be (50 - 36.5) x 2 = 27%

So you'd need a Tx setting of 36.5% to get the same gain in rate mode.

Well that's the theory anyway. In practice, the gyros don't usually follow such a linear relationship, but it's a good starting point.

Another pic showing the 63.5% value...

[joe.lel]

All sorted !!!!

Thanks for the call Liam

[liambaker996]

no problemo joe glad it worked
cheers Liam