DH 91 Albatross

Quorneng said "I think it may be wise to reorganise the motor wiring onto two channels so I can switch off the outer pair at will. It can then be launched as an 'inboard' twin until at sufficient height to safely run on all four.
I am not using dual ailerons so the flap channel is free. It should all work providing such a mix does not upset the gyro and I can remember how I did it on the now defunct Skymaster. "
When you figure it out, would you be kind enough to post the wiring diagram.

crash
Crash it appears I cannot do as I intended as the gyro uses the 'Gear' channel to switch it on/off so I was already using the 'Aux1' channel to work the retracts.
However I will have to check but I believe you can set the gyro to be 'on' all the time so releasing the 'Gear' to be used for the retracts. This would make the 'Aux1' channel free to be used as the throttle the outboard motors.

The wiring on the plane is fairly straightforward. Simply connect the outboard motor ESCs servo plugs to the Aux1 channel like this.

The thin ESC to Rx lines are of course 2 wires if an OPTO ESC (the Rx then has its own supply via 'Bind') or 3 wires if a BEC ESC (but leave only 1 red wire actually connected).

By far the biggest issue (at least it is on a DX6i!) is programming the Rx so the throttle movement is duplicated on the Aux1 channel and is also switchable on/off. Although there are lots of videos on YouTube how to programme the DX6i I have not found anyone who has actually done what I am after.
I suppose not that surprising as when do want to switch of a second motor in flight? Unless you a flying a tandem engine job like the Skymaster. By the time people want to fly a four engine thing they are likely to have moved onto a much more capable Tx.

Although In its day the DX6i was very popular it became famous for having is internal programming created by some computer geek who had never flown RC. In addition the manual was equally notorious for describing what the DX6i could do but not describing how to achieve it. :woohoo:

notorious for describing what the DX6i could do but not describing how to achieve it.

Like the Taranis! It takes a lot longer figuring out HOW, than it does to DO! (once you know how!)
I ended up writing down everything I did, a button at a time, so I could see what did or did not work, and effectively wrote my own manual for the darn thing - then they updated the software, and I'm having to do it all again, as the old method was all wrong! The only switch that works the same is the one marked power!
:dry: :silly:

Quorneng. First, thanks for posting the wiring diagram, that is very useful.
You can indeed program an admiral gyro to be on all the time, freeing up the gear & aux1 channels. Instructions are available on you-tube.
I am not sure about the DX6i but I think on my DX6e you should be able to designate a switch to aux1 & then create a mix of throttle - aux1.
I will have a play around with it.

crash
The problem is my Lemon Gyro V3 does not have an 'on all the time' feature although the V1 did. According to the RC Groups official history Lemon were pushed to encompass more channels, DX8 and above, to allow control of the gyro gain to be included.

I have been able to get Aux1 to mimic the Throttle on my DX6i and be controlled on/off by the flap switch to kill the outer motors at will but as far as the Lemon Gyro goes that would mean the retracts would also switch the gyro on and off. At this stage I feel the gyro is more important than being able to cut the outer motors. I do need the retracts operating as the only way to hold the plane for a hand launch is by the wheel wells and it has to be a belly landing.

The last option would be to physically cut out the outer motors (very easy to do) and fly it as a twin until I am happy it flies reliably.

Of course all this is academic whilst the lock down persists and the latest UK mortality figures seem to suggest it might be for a bit longer yet.

Could you use a servo tester to give say half power on the two outboards, for initial flight testing?

This just popped up on Facebook -
Chris Golds' Albatross