Throttle "Governor"

[hillberg]

The Solar,T62T32 has 3 types of FCUs 1- Fly weight hydro mechanical,2-Electrical Hydro mechanical & 3- Digital control Head.common problems for #2 are spring & torque moter failure along with RF spikes, the Didigital has too much going on and will shut down if rates & limits don't match onboard logrithims ( Ask the guys with the turbine Luscum project)# 1 is great but hard to get #2 is all over. #3 forget it.
An engine slaved to an electrical system is a problem if over rocks & trees, (Battery,Generator short,Broke wire,dead bus,)A pilot needs direct control of power when he needs to get out of trouble.
Had good friends die from FADEC ( Found Another Dead Engine Control.)

[HobbyCAD]

Originally Posted by hillberg

The Solar T62-32 has 3 types of FCU's. 1- Fly weight hydro mechanical, 2- Electrical Hydro mechanical & 3- Digital Control Head.

#1 is great but hard to get. #2 is all over. #3, forget it.

Yup Don, mine was #1, the mechanical unit using the bobweights and fuel pressure to regulate RPM.

[StanFoster]

Todd- .... Your questioning the throttle has me now thinking about it. I love the way mine has been working, but admit you bring up a valid point. Don and Francois, you two know far more about this than I ever will. Let's say I am flying along and my engine goes to idle..........48000 rpm instead of 61500. I need a mechanical link to my fuel control arm and need to operate it fast. It looks to me that it should be on the collective as I need my hand there during this incident. This mechanical overide has to allow the fuel control arm to freely move when its working properly, yet be over riden should the governor fail. I am ignorant how to go about this in a way I could easily modify my own system. The throttle part never concerned me, but I have thought that the governor just has to be trusted completely or an auto will result. I could see having a cable attached to the throttle grip that could move the fuel control arm but would have to have a way to instantly engage it to overide the governor, but be freely floating while the governor is working fine. Any thoughts? Can one even control the power precisely enough as that fuel control lever moves very little. Maybe I have been flying blissfully and ignorantly. I do fly like the governor or anything else could quit anytime, simply because anything mechanical can quit! Stan

[HobbyCAD]

Stan, what you are referring to, is already implemented in modern FADEC helicopter engines. It's called freeze mode. If the FADEC misses a beat, or you have a total power failure, the engine throttle mechanically moves to 75% power. Might not be enough to pull you into a hover, but it is enough to do a running landing.

I would place your little camera (or a GoPro, I use 3 for our test flights) looking at your throttle arm, that one that hardly moves, but when it does, it moves very rapidly. See where it is at normal operations, and figure out a way how to get it to lock there, in case of an emergency.

I'm thinking of a horizontal plate with a V cut into it. The V open end is slightly wider than the full travel of the arm. Position the plate with the middle of the V at the point of 75% power, just next to the arm. Hinge the one side, mount a pull wire on the other. If you pull on the wire, the V moving over into the arm arc will force the throttle arm to move into the centre of the V groove, overriding the drive force keeping it anywhere else. This will place the throttle locked at 75%. Get my idea?

[StanFoster]

Francois- Your explanation is extremely clear, and thanks for that. I see you are just saying over riding it going to idle, and your V notch idea seems brilliantly simple. A simple push pull choke wire could apply power back even more than 75% possibly. I do have two micro switches on my fuel control arm that shows when I am asking almost 100% by turning on a yellow light, and a end micro switch shows when I am at 100 %. Thanks for giving me something to chew on. I like your idea of immediately getting the power applied, but not trying to fine control it. Stan

[HobbyCAD]

Yup, with this method, just as in modern helicopter turbine engines, you can "freeze" your throttle to a predetermined setting.

Now see if you can get Gabor to bite on adding a helicopter to his collection. Now that his daughter is out of the house, he just might have some spare cash to part with. Only problem, will the "Queen" know, or will it be domestic fraud.....

[hillberg]

That's what I designed for the Jet Exec, Governor with a manual override that a pilot can use when the electrical power goes out, overspeed,underspeed, spring or torque motor failure ,The pilot must be the one in control. Not a wild electron.
It was flown all hand & gov with no ill effects.

[PW_Plack]

If all you do is freeze the fuel flow setting at 75% power, isn't there a risk of exceeding redline on the engine when you drop collective? I suspect the Helicycle design leaves lots of RPM headroom, but an unloaded turbine even at low power settings would just spin up till it came apart, right?

[hillberg]

The rotors load the system limiting the rate or acelleration & you can hand adjust with throttle From 95% to 104% took 3 seconds lowering collective . Not a problem.-Even in reversion with the Bell 407s FADEC the pilot is cautioned about abrubt collective moves.
The T62 has a narrow opperating band in reguards to acellerating from low speed drooping to compressor stall.keep power @80% for best results.

[Arnie Madsen]

Todd (baronpilot) ..... I am going to sidestep your Helicycle electronic governor question and focus on helicopter piston engines for a minute.

I have often wondered why these (pictured below) simple bullet proof mechanical governors have never been used instead of the crude throttle correlator on the collective .

Pictured below are two examples of self-contained mechanical governors , one belt driven , one gear driven. They are excellent governors for engine rpm control.

They achieve tight RPM regulation without hunting. They are used on large gas powered welders , most farm equipment , and other engines that require constant RPM under varying loads.

I am sure one of these on a Lycoming would hold a constant rpm and give trouble free operation for thousands of hours.

.