DX7 throttle faux expo?
12-20-2006, 05:48 PM
#1
DX7 throttle faux expo?
My MW44 Gold has a very non-linear throttle response with alot of RPM in the last 1/4 of the stick. I "use to use" reverse expo the make it feel more linear on my 9C TX. The DX7 does not have expo on the throttle, let alone reverse expo.
Here's my thoughts..
Set low throttle travel to max, say 140% and set high throttle travel to say 50 or 60%. Teach the ECU these settings. Viola!
Comments? Suggestions?
Dave
Here's my thoughts..
Set low throttle travel to max, say 140% and set high throttle travel to say 50 or 60%. Teach the ECU these settings. Viola!
Comments? Suggestions?
Dave
12-20-2006, 06:52 PM
#3
RE: DX7 throttle faux expo?
Bob,
Not that I can see. I've D/L the manual and don't see any curves for the aircraft mode. Maybe having a throttle to throttle mix might do it? Say mix in alot from half to low and then mix out alot from half to high. I wonder if the ECU will have trouble with expanded or compressed endpoints?
Seems like an interesting subject!
Dave
Not that I can see. I've D/L the manual and don't see any curves for the aircraft mode. Maybe having a throttle to throttle mix might do it? Say mix in alot from half to low and then mix out alot from half to high. I wonder if the ECU will have trouble with expanded or compressed endpoints?
Seems like an interesting subject!
Dave
12-21-2006, 06:53 AM
#4
RE: DX7 throttle faux expo?
Just rec'd this from Gaspar. Looks like I'm on the right track!
Hello Dave,
>
> For the ecu you can set the endpoints in any place you
> want, it will work, you only should re-learn the ecu
> after any change to the TX. Depending on what the TX
> do, this can or cannot solve your issue. If the tx
> allow that a servo connected to the throttle channel
> be at center position with the stick at center, and
> from center to up move significantly less angle than
> to center to low, this will be OK.
>
> The ecu sets the RPM of the engine linear to the
> throttle position, from idle to maximum. If you have
> the idle at 55k and max to 195k, setting the throttle
> to 50% the engine will run at 125K ((195-55)x50%)+55)
> that is the 50% RPM between 55 and 195k.
>
> The problem that you feel is that the 44 have a
> unusual wide operating margin from idle RPM to top
> rpm, and from idle to 110K (that is double rotor rpm)
> the engine only increase the thrust on about 2 lb. AT
> 125k (50%) throttle you have around 3.2lb, at 75%
> (160k) you have about 6lb.
>
> Doesn't matter if the maximum is at 70% or 150%, when
> you set the maximum it store the received command as
> 100%. As long as the TX send linear throttle movement,
> the engine RPM will follow linearly the rpm with the
> throttle movement.
I'll give it a try soon.
Dave
Hello Dave,
>
> For the ecu you can set the endpoints in any place you
> want, it will work, you only should re-learn the ecu
> after any change to the TX. Depending on what the TX
> do, this can or cannot solve your issue. If the tx
> allow that a servo connected to the throttle channel
> be at center position with the stick at center, and
> from center to up move significantly less angle than
> to center to low, this will be OK.
>
> The ecu sets the RPM of the engine linear to the
> throttle position, from idle to maximum. If you have
> the idle at 55k and max to 195k, setting the throttle
> to 50% the engine will run at 125K ((195-55)x50%)+55)
> that is the 50% RPM between 55 and 195k.
>
> The problem that you feel is that the 44 have a
> unusual wide operating margin from idle RPM to top
> rpm, and from idle to 110K (that is double rotor rpm)
> the engine only increase the thrust on about 2 lb. AT
> 125k (50%) throttle you have around 3.2lb, at 75%
> (160k) you have about 6lb.
>
> Doesn't matter if the maximum is at 70% or 150%, when
> you set the maximum it store the received command as
> 100%. As long as the TX send linear throttle movement,
> the engine RPM will follow linearly the rpm with the
> throttle movement.
I'll give it a try soon.
Dave
