Transmitter settings help

[Mordecai]

I've got a DX6i, and been using it with a Nano and 130x. Other than the sticks, I just use the idle-up switch and throttle hold.

Whilst programming my new Blade 300 CFX, I noticed the aileron, elevator and rudder have a setting of 100% at position 0 and 85% at position 1.

Can anyone explain in what circumstances I'd use these? I've never felt the need in the past but wondering if I may need to on a larger heli (and also curious!).

[Angelo A]

These are your dual rates. You can assign the switches on the tx to have different rates at different positions (100% at Pos0, 85% at pos1, etc). For the dx8 it has a switch for each parameter or you can assign all three elevator, aileron and rudder to one switch for ease. You can also add expo to each position as you like. It tames the bird down on different switch positions. Experiment with it.

[ArchmageAU]

Originally Posted by Mordecai

I've got a DX6i, and been using it with a Nano and 130x. Other than the sticks, I just use the idle-up switch and throttle hold.

Whilst programming my new Blade 300 CFX, I noticed the aileron, elevator and rudder have a setting of 100% at position 0 and 85% at position 1.

Can anyone explain in what circumstances I'd use these? I've never felt the need in the past but wondering if I may need to on a larger heli (and also curious!).

Multiple DR's are used to allow different sensitivities for things like landing (precision) and flying (less precision).

From: Newbies guide to the DX6i for RC helicopters

Originally Posted by ArchmageAU

....

DR, Expo and Travel Adjust, how it works and what you need to know

If you are new to RC flight, you will be new to the terms of DR and expo.

DR is short for Dual Rate. What this means is that the rate the stick moves from end to end does not match the speed the servo moves from end to end. In short it is a limit on how far the servo is supposed to move at maximum stick defelction. A DR of 50 means at full stick deflection, the servo moves half the distance from middle to end.

Expo is short for exponential. Exponential describes the type of deflection from a linear curve you want the movement of the servo to have.

All you really need to know is that for Spektrum transmitters (like the DX6i), positive expo makes the servo have smaller defections round centre stick but accelerates till it meets full throw at maximum stick deflection. Negative expo has the reverse affect (more sensitive round centre stick and still slows near maximum stick deflection).

...

To make a heli easier to fly, first reduce DR on the cyclics. This reduces the maximum speed at which the helicopter will flip and roll. Once this is done, then increase expo to taste. The goal is to make the controls natural enough that the helicopter moves as much as you expect based on the stick inputs you give. This will change for each different sized helicopter.

Too much expo, a heli feels mushy. You have to chase the corrections around with the stick, then all of a sudden they rush in. Too little expo and the heli feels twitchy, it's hard to get it to stabilize properly.

Too many new people equate expo with experience. It is just not so. Bert Kammerer uses 20% expo on most helis. Few have more experience with RC helicopters than Bert. Expo is a personal preference thing, nothing more.

For the mCPX, some may like to start with 100% DR and 0 expo, others may start with 70% DR and 30% expo, others may start with 40% DR and 20% expo. Until you get a good feel for flying helis start with a low DR and work up.

For a beginner thumb flyer start with 40% expo and DR to suit level (40 - 70).
For a beginner pinch flyer start with 20% expo and DR to suit level (40 - 70).

As you get more comfortable, increase the DR.

Some higher end transmitters (like the DX8) allow DR values as large as 150. Until you are trying advanced 3D smack moves, a DR of 100 should be fine.
...

You can make DR&expo switch on a single stick. (ie. Set D/R COMBI switch to "RUDD" will switch DR&expo for Aileron, elevator and Rudder just on the Rudder DR switch).

btw, I effectively fly my 450X on DR 130 (precision hover with DR 104, test/landing DR 65), to others it flies "twitchy", but it's the way I like it.

[Mordecai]

Thanks for the replies guys. I've been experimenting with DR and expo in the transmitter settings, and like you say having one button on the transmitter to affect them all at once makes sense, but I never see myself switching each of them independently. Interesting concept - I guess a good way to try out new settings without losing old ones initially.