Mixture assignment on X52 joystick

[Kneed]

I just started using the XP12 version of this aircraft. Originally for other aircraft my X52 joystick 'small knob' was set to 'mixture'. When I reassigned joystick settings for the MU-2 it remained set. 

I have found that the engines will not start unless I turn that knob back slightly and back to the full mixture. The 'main fuel valves ' are open . After one engine is started. The second needs that same procedure of turning back the knob slightly and to full. That causes the first engine to start to wind down but as soon as it is back to full, it revs up again. It is like that knob is controlling the fuel input. I tried setting it to none but the engines will not start at all then. I cannot find any reference to mixture in the manual.

Any suggestions?

[tkyler]

The quick answer, don't set any hardware to mixture, only NONE (more below)....and save the Moo joystick config so you don't have to reassign every time.  

You of course mentioned you set it to NONE, but the engines did not start....in this case, I suspect some other input is not set (fuel valve or condition lever position, RCS switches to RUN, etc.) or perhaps some funky initialization situation if you were trying all these changes in a narrow span of time during the same "flight session".   I would ensure no hardware is set to Mixture,  and then double-check any other lever assignments against the setup docs, and just for good measure, reload the aircraft (best using the 'developer' menu)... and retry the engine start per the checklist.

1 hour ago, Kneed said:

I cannot find any reference to mixture in the manual.

The term "mixture" is generally associated with piston engines and not typically used with regards to turbines, which are controlled through FADECs or other fuel controllers for which the pilot has no input to control "the mixture"; however,  in X-Plane, the "Mixture" dataref does indeed control the fuel to the engine......any engine.... piston, turbine, jet.  Its one of the oldest and earliest X-Plane dataref variables and when that sucker is 0, engines are not going to start/run.

As such, I manipulate this variable several differing ways to simulate no fuel to the engine, i.e via the fuel valve, the condition lever position, or whatever else can keep fuel from reaching the engine.  So any hardware that is assigned to the mixture will be "fighting" with my own code and cause issues.

-tkyler

Edited May 28, 2023 by tkyler

[Kneed]

 

Thanks for the quick response.

I have an MU2 joystick profile saved. I didn't know I had to clear mixture before starting the setup for the MU2. And I'm not sure it would have helped anyway

When it would not start with the mixture set to 'none' , all I did, without changing anything, was set it back to mixture move it to full and it immediately started. So, I think everything was set correctly.

Also, it will not shut down unless I turn the 'mixture' all the way down.

The condition levers are set to TAXI , power levers  are at slightly above Ground Idle. SRLs are on and Run Crank to 'RUN'. Fuel valves are open. I would have thought that if the fuel valves were open it would override any mixture setting or a none.

I know mixture is for piston engines but it sure is affecting this aircraft.

If I start using the ' engines running when loaded feature all is good . however I had to use the mixture to low to get the engines to stop.

 

I'm also having a terrible time to get it to move forward to Taxi. I have played around with the on the locks thing but so far no success . Still have a few more thing to try. Would like to get the mixture thing resolved first.

Any other suggestions?

[tkyler]

1 hour ago, Kneed said:

Would like to get the mixture thing resolved first.

I'm not sure what is going on...there should be no mixture assignments anywhere in your setup and it should work fine.   Note that some cockpit switches set the mixture "per event" in some cases, that is when the switch is actuated, rather than 'polling' the switch position every flight loop.  This is a coding choice on my part.  So if you set your mixture assignment to NONE, but your joystick had set it to zero before hand...and you did not actuate any other switches or reload the aircraft, and simply tried to start it, it wouldn't start in these cases.  I make the assumption that any hardware axis is never assigned to mixture, which is the logic behind my suggestion to ensure no axis is assigned to mixture, then reload the aircraft and try again.

-tk

Edited May 28, 2023 by tkyler

[Kneed]

Ok thanks

I'll set it to full on mixture then set it to none. save and restart XP.

I don't think removing the preferences folder would help but I will try that after your suggestion if it doesn't work. Looks like I'm the only one with this problem. weird because i'm sure there are a lot of X52 joysticks out there.

I'll do a search for mixture in joystick and keyboard just in case something else is set.

I appreciate the help. Ill let you know if i succeed

Cheers 

[Kneed]

Your suggestion worked. Set the mixture to max. then changed the joystick setting for mixture to none. restarted XP and this time the engines started.

The blades were 'unfeathered' prior to starting the engines. I'm not sure if that is normal and if the unfeather button should be pushed. I did and you could hear some noise I assume the unfeathering process anyway. Still could not get any Torque or forward motion to Taxi . Tried to shut down the engine and at one point it said put the power levers in reverse. That caused reverse motion. Went back to Ground Idle and was now able to get torque and forward motion.

Is that normal? at least it worked. Still have a bit of getting familiar with this aircraft. Fun to fly though.

Thanks for your help

[tkyler]

3 hours ago, Kneed said:

Is that normal?

it is.  see MU2 docs, section titled  "Prop Locks" 

http://togasim.com/mu2docs/systems_descriptions/engine_prop/engine_prop.html

specifically....

Quote

If you do not take the props off the locks after engine start, you will get no thrust when advancing the power levers and go nowhere.

Definitely takes a bit of getting used to compared to other 'free turbine' engine types, but quite natural once you're comfortable with it.

-tk

Edited May 29, 2023 by tkyler

[MANOLO]

@Kneed

The MU-2 is a fixed-shaft turboprop with a Garrett TPE331 type turbine and is different from most turboprops that are split shaft/free turbine, the typical PT6 turboprops. Perhaps for this reason, you do not get used to the fact that there is no third lever that you call the mixture.
If you want to know the difference between these two types of engines, you can read the attached article from the FAA manual.

On the other hand, I recommend you faithfully follow the checklist published by the author. Doing this means getting rid of most of the problems you encounter when starting to learn to fly a plane, and it helps you understand why things are.
And more especially, I recommend you to use the xchecklist recently published by @goofy in this same forum. You will not regret.

 

TURBOHÉLICE.pdf

[tkyler]

Just a rambling blurb here.....   The MU2 for X-Plane has been out a long time and I've answered a lot of support questions over the years... and without a doubt, many folks aren't aware of Garrett's/Honeywell's TPE (Turbo Prop Engine) fixed-shaft type of turboprop and its operation and are only familiar with the 'PT6 paradigm'.   In many cases, this has resulted in such customers frustration with the product....initially....however, once you get all the controls set up properly, and understand the operation and get a few flights under your belt, that tends to go away and I've seen these same customers really grow to like the MU-2.   One document refers to it as "a pilots turboprop"...that is simpler operation, fewer controls,   instant thrust, etc" and I am in agreement with that assessment.   My earliest memory of a MU-2 was when I was about 8 and one took off from my local airport....and I'd seen a lot of airplanes takeoff, my dad and I were "watchers"...but that MU2 was noticeably faster on climbout....really fast...compared to other turboprops and I've loved it ever since.  Its not the kind of flight sim product that sells like an airliner, but I'll probably never stop tweaking on this one,  it really is my "personal X-Plane project".  

-tk

Edited May 29, 2023 by tkyler

[Kneed]

6 hours ago, MANOLO said:

@Kneed

The MU-2 is a fixed-shaft turboprop with a Garrett TPE331 type turbine and is different from most turboprops that are split shaft/free turbine, the typical PT6 turboprops. Perhaps for this reason, you do not get used to the fact that there is no third lever that you call the mixture.
If you want to know the difference between these two types of engines, you can read the attached article from the FAA manual.

On the other hand, I recommend you faithfully follow the checklist published by the author. Doing this means getting rid of most of the problems you encounter when starting to learn to fly a plane, and it helps you understand why things are.
And more especially, I recommend you to use the xchecklist recently published by @goofy in this same forum. You will not regret.

 

TURBOHÉLICE.pdf 1.1 MB · 0 downloads

Thank you all very much for the advice . I was using version 1.1 of that cklist . I see 1.2 has a procedure to ensure that the propeller is 'on locks'. I haven't tried it yet. I'm sure it will  good.

I have a feeling that this will be my new favourite aircraft.