Align 3G Setup Tips
This is a copy and paste orginally written by Dennis at archeli. But after reading this I realized the way I have my 3G setup, it's probably working against me. With more of us at the field making the move to the 3G system I thought I would share it.
DIR mode cyclic values are to teach the 3G system it's limitations, not to set your desired cyclic pitch.
This is why part of the 3G setup is the aileron & elevator LIMIT. The 3G needs to know where to stop tilting the swash.
DIR mode disconnects the cyclic gyros so you can measure your cyclic pitch accurately.
Then there's the Limits: A.Lim & E.Lim to teach the 3G where to stop.
It's similar to a tail gyro limit setting. A tail gyro needs to know where to stop.
The 3G also needs to know where to stop, & it needs some room to play with.
When we setup a tail gyro, we allow full travel of the tail pitch slider with no binding.
We need to do the same with the swashplate for the 3G, up to a maximum of 14°. (I have found 12° is a nice value that won't bind the swash in the "corners" while allowing more than adequate swash travel)
I have my 3G set for 12° cyclic pitch in DIR mode (which is 75% swash mix with swash mix EXP enabled)
After I complete the 3G configuration & exit setup mode, I roll back my cyclic swash mixes to 60% for my desired roll rate. (I came up with this value by feel in flight, not by a measured pitch value, just like we do with tail gyro pirouette rates)
Ideally, after you exit DIR mode, you want to roll back your swash mix cyclics for a slower roll/flip rate.
What this does is leave the 3G some room to play.
If you like the roll rate of 12°, set the DIR values higher up to a max of 14°, once again, so the 3G has room to play.
eg: 12° in DIR mode, will give a very fast max roll rate, but the 3G knows it's limit is 12°, so if you are already at max roll rate, the 3G simply CANNOT command a higher roll rate if it needs to due to a gust of wind etc, so under this circumstance the 3G WILL NOT perform as intended.
Imagine if you only set your usual 7~9° on a windy day.
After exiting DIR mode, reducing the swash mix values reduces the roll rate to a more acceptable level, but the 3G knows it can tilt the swash more if it needs to, to keep the commanded roll rate consistent.
What you need to do is set 12° of cyclic pitch in DIR mode on the aileron, set elevator to the same value. (The 3G automatically calculates a cyclic ring so there's no need to measure the elevator cyclic pitch, just set it the same as the aileron)
Go through the A.Lim & E.Lim & correction directions with these values.
Do this regardless of how much cyclic pitch you usually run, you are teaching the 3G the MECHANICAL LIMIT, just like you do when setting up a tail gyro.
Then roll back your swash mixes to suit your flying style (keep ELEV the same as AIL) after you fully complete 3G setup mode & test fly the model.
I believe that the majority of 3G problems that I have read are caused by incorrect setup, &/or misunderstanding of the 3G's configuration parameters.
This is most likely the reason Align only released a simplified Plug & Play version for now so we can familiarise ourselves with FBL principles before giving us access to the advanced parameters.
If you are running V2.1 & have the USB interface, I recommend leaving the cyclic swash mix at the same values in the Tx as you did in DIR mode, & adjusting the roll & flip rates via the software.