MT electric governor?

[rdamazio]

Originally Posted by rocketman1988

Well, the biggest loss is cash...the MTV9 is a little more expensive.

The gain is in weight, about 11 lbs heavier and, according to the techs, reliability of the prop...I am just relaying the message I received, YMMV

Thanks. Yeah, 11lb seems significant.
Any sources you can point me to so I can understand a bit more?

I'm mostly thinking that a heavier prop probably takes more power from the engine just to overcome its inertia, so I'm curious to know more about performance.

[paul330]

Originally Posted by rdamazio

I'm mostly thinking that a heavier prop probably takes more power from the engine just to overcome its inertia, so I'm curious to know more about performance.

Er, no.......

It may take marginally longer to spin up but "take power from the engine" - no.

Electric CS is meant for use where no hydraulics are available (such as an auto conversion). The first choice is hydraulic. Sure, it will work. So, if you are trying to go single lever and the EFII needs an electric drive to interface with (I'm not familiar with the application), then there should be no issue other than extra cost.

[rdamazio]

Originally Posted by paul330

Er, no.......

It may take marginally longer to spin up but "take power from the engine" - no.

(just in case it wasn't clear, that last question was about the heavier, stronger prop, not about electric governors anymore)

Well, it's additional mass that's being moved (rapidly, in fact), so the force/torque to move it needs to come from somewhere?

[scsmith]

Originally Posted by rdamazio

(just in case it wasn't clear, that last question was about the heavier, stronger prop, not about electric governors anymore)

Well, it's additional mass that's being moved (rapidly, in fact), so the force/torque to move it needs to come from somewhere?

F=MA.

It takes more torque to accelerate it, but it does not take any more force or torque to keep it moving at a fixed RPM.

It does take a little more lift from the wings to support the added weight, so there is a little bit more drag. But no - a heavier prop does not reduce cruise speed significantly just because the engine has to turn a heavier prop at a constant RPM

[RicoB]

I am running MT electric on RV9a and a O320, It works fine, haven't noticed any hunting. If you are not doing Acro it shouldn't be a problem.

[svyolo]

I am a little surprised no one has used a linear servo to control the CS prop control, connected to some type of controller. You could use a fairly simple map of MAP vs rpm to control the prop. You could also over-ride the servo manually.

That and EFI of some flavor, and you have most of a FADEC. Real FADECs also have some built in limiting functions, like rpm and overtemp limits. But it would give you single lever control.

[rdamazio]

Originally Posted by svyolo

I am a little surprised no one has used a linear servo to control the CS prop control, connected to some type of controller. You could use a fairly simple map of MAP vs rpm to control the prop. You could also over-ride the servo manually.

That and EFI of some flavor, and you have most of a FADEC. Real FADECs also have some built in limiting functions, like rpm and overtemp limits. But it would give you single lever control.

That's an idea to keep in mind - sounds like something I can experiment with after it's already flying, since it'll need the same cable installation and just adding the servo and controller (I'd probably think of a PID controller to maintain RPM rather than a fixed mapping).

[rocketman1988]

Here is an article discussing the Cirrus single lever system. It is mechanical but would lend itself, in concept, to automating the prop function.

The mod you are describing could certainly be accomplished but the question is why?...

[svyolo]

I don't know anything about Cirrus's system. I think you would need a fairly fast servo, and it needs to be able to be overridden manually, and very easily overridden.

Other than than, I really don't see any problem. A true FADEC isn't mechanical, but basically FBW for the engine. Lots of new cars have been that way for a 10 years or so. You need an electronic throttle as well.

Lots more complicated, lots more testing. And you would still need a mechanical backup on a plane. The benefits would need to pay for the cost. I think the big Continental Lancair uses in the new Evolution automatically chooses to go LOP when it is OK to do so. You can accomplish that with EFI.

A single lever control should be comparatively easy.

[rocketman1988]

https://www.flyingmag.com/how-cirrus...-control-works