3GX and DSX9 swash EXP

[MattHarper]

Okay, hands up, I'm struggling to find an answer to this on HeliFreak, RunRyder or even Google.
Do I enable or disable EXP in the swash menu when running a 120 degree CCPM setup required by the 3GX.
Any ideas ?

[dunny]

You can have expo enabled or disabled it depends what you looking for, obviously expo will make it a bit smoother around centre stick.When setting up the 3gx in dir mode you must decided before hand which you want to run ie enabled or inhibited, if you change later you will have to run dir set up again as your max pitch range will change.

[MattHarper]

What's the difference between EXP in the swash menu and expo in the pitch curve. I recall that EXP should always be enabled on a CCPM machine to linearise control movement.

[coolice]

Hey.

I must admit to leaving it off in the swashplate menu, prefering to set expo on the individual controls and if I need to soften the collective pitch response, do so by programming an almost "S" shape pitch curve.
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[Steve]

Expo 'on' in the swash mix menu is a built in feature of the DSX9 radio (and many others) that attempts to turn the rotational output of the servos into a linear control output, thereby making your heli respond more linearly with your stick inputs. This should take affect regardless of whether the heli is flybarred or flybarless.

Expo 'on' in the pitch and throttle curves, and the programmable mixes simply smooths out the corners of the curves, making the response across the stick range more smooth.

However, there are many other factors at play in helis such as swash mix values, servo endpoints, throttle curves, pitch curves, control axis exponential, dual rates, deadband regions etc etc etc etc, so the effect of having the expo 'on' usually gets nullified by something else in the radio setup.

For me, I always have it on in all functions on all controls.

If you are about to change the setting from on to off, or vica versa, be sure to check the overall settings against the heli mechanics. For example, if you currently have +/- eleven degrees collective pitch on the heli and you just switch it on in the swash mix menu for collective without changing anything else, you'll probably find that you've now only got +/1 nine degrees pitch or maybe even less. You'll need to re-measure and re-tweak other things to get your basic flight envelope back.

[MattHarper]

If you are about to change the setting from on to off, or vica versa, be sure to check the overall settings against the heli mechanics. For example, if you currently have +/- eleven degrees collective pitch on the heli and you just switch it on in the swash mix menu for collective without changing anything else, you'll probably find that you've now only got +/1 nine degrees pitch or maybe even less. You'll need to re-measure and re-tweak other things to get your basic flight envelope back.

Yeah, I've fallen foul of this before. The bottom line is what is best for a 3GX setup, swash EXP enabled or disabled ? With my v-bars, being a single servo mix, EXP doesn't enter in to the equation, so the v-bar sees a linear output from the receiver. Any ideas ?

[coolice]

Hey.

I'd leave it turned off I think to be safe.
The new V2 3GX firmware introduces some new cyclic and collective tweeks which can smooth or increase cyclic/collective response, so I would just use these parameters to make expo type changes which this one can add in the swashplate menu.
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[MattHarper]

Thanks Guys.
I'm going to assume that the 3GX will correct for servo/swash geometry in a similar way to the EXP function in the DSX9. Having played with the software, I can't help thinking that I should have bought another v-bar, time will tell I guess.