Prop axis and brake axis issues.

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Tutmeister
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Prop axis and brake axis issues.

Post by Tutmeister »

I'm having an issue with prop assignments with my b17.

I have throttles, prop and mixture all assigned on levers via fsuipc.
The issue I have is when I reduce prop pitch I am unable to increase it again even thought the levers move back up. It is almost like the prop pitch has gone too far and gone past a minimum limit.

This video below is on a fresh install of fsx steam with only fsuipc and the b17 with accumsim latest update installed.

To illustrate the issue I have assign prop 1 to fsuipc and prop 2 is set through fsx only. I have checked the calibration is fsx and it is full with zero null zone.
You can see that when I move the levers to minimum the fsuipc one (prop 1) drops to a lower rpm than the fsx assigned one (prop 2) even though both virtual cockpit levers are in the same position.

Then when I move both levers back up the fsx assigned one (prop 2) increases rpm where as the fsuipc assigned one (prop 1) stays where it is even though you can see the virtual cockpit levers both back up at the top.

[youtube]http://www.youtube.com/watch?v=KteSIZdbPNA[/youtube]

The only way to fix this is to completely shut down all the engines and then restart them.

I can't leave it assigned through fsx as I fly lots of different aircraft. It needs to be fsuipc or nothing. The only other thing I can do is not touch the pitch and let the crew deal with it.
I have the same problem on Prepar3d v3 and fsx, both tested on clean builds.


The brake issue is equally perplexing. If I press a toe brake you can see the pedal in the cockpit go all the way down. When I press the other toe brake the pressed one releases. So basically you are unable to have both pedals depressed in the sim. Any time I have both physical pedals pressed they sort of fight against one another in the cockpit. As soon as I let off one of them the pressed one works.
I have tried both through fsx and fsuipc with no change. In all other aircraft everything works just as it should.

Anyone got any thoughts?
Thanks
Chris
Owner of Fulcrum Simulator Controls
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alan CXA651
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Re: Prop axis and brake axis issues.

Post by alan CXA651 »

Hi.
I have two ch quad throttle units , and have my b17 set up in fsuipc , i had trouble mapping prop/mix to the individual engs , till bill gave me the answer , i can control my engs individually with no problems , but if you had one set in fsuipc and the other in fsx to test prop lever moivment , in fsx you will not get as much movement as fsuipc , fsx does not take in to account the feather position , which is full down ,this might account for the lower end of prop movement, cannot explain the brakes , unless there is a control confict somewhere.
did you set up the mix/prop controls on p2 of fsuipc axis to map4 and p4 to no reverse.
regards alan. 8)
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Tutmeister
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Re: Prop axis and brake axis issues.

Post by Tutmeister »

Fantastic! thanks for that alan. That will explain what is happening with the props. The blades look like they are feathered when the engines are stopped. You are right and it shows in the video I posted, fsx doesn't move as much as fsuipc.

So this raises 2 questions. How to unfeather them and how to correctly set up pitch so they don't feather. I'll have a play around.

Thanks for the pointer. :)

Still no clearer about the brakes though. It only affects the b17.

Chris
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alan CXA651
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Re: Prop axis and brake axis issues.

Post by alan CXA651 »

Hi Chris.
I did feather/unfeather when i was getting all the controls set up , but cannot remember the sequence i did , i will have to play around myself , i know its easy to feather , but i think its not easy to unfeather if memory serves me correctly.
regards alan. 8)
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alan CXA651
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Re: Prop axis and brake axis issues.

Post by alan CXA651 »

Hi Chris.
Just tried the feather function on my setup.
Pulling prop lever all way back , does nothing on a stopped eng , engine has to be running for it to go into feather mode,once prop moves to feather , the engine will stop,if you then move lever fwd to fine position , the props unfeather , then you can restart the eng.
regards alan. 8)
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Tutmeister
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Re: Prop axis and brake axis issues.

Post by Tutmeister »

With mine I can pull it all the way back but when I move it forwards again it doesn't increase rpm. It seems stuck in feather. I have to stop the engine and restart to get it out of feather. It would be good if there is a way to stop them from feathering when the lever is pulled back.

Chris
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WB_FlashOver
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Re: Prop axis and brake axis issues.

Post by WB_FlashOver »

I have had issues with my props feathering during flight and it sounds like the same issue here. What causes my issues is pulling power and props back too far while descending for approach. I have made a habit of always keeping RPM's above 900 to 1000. Over 30+ inches I seem to be able to reduce RPM's a little more but still try to keep above 1100 to be safe. I am using only an X52 Pro so props are assigned to a rotary axis in FSUIPC as well as all other axis controls.

For the brakes I would suggest looking in the FSUIPC4.ini file. Under the [General] section find BrakeReleaseThreshold=xx. Change the value to zero (0). My brakes are on the thumb slider and if I leave the default of xx (75 I think it is) my brakes go part way down and then come back up as I brake harder. (0) fixes this issue.

And always make sure that FSX and/or A2A's B-17 Input Configurator do not have axis assigned that will interfere with FSUIPC4 settings. Another issue I've seen on friends system is when they have two or more controllers attached. You have to make sure to switch to each controller at the top of FSX Axis Controls to check each one individually. FSX likes to randomly assign axis once in a while.

Good luck Sir.
Roger

EDIT: My apologies. During my flight this morning I realize the minimum RPM I pull back to is 1400 but prefer 1500+
-- Fly Well, Be Nice, Have Fun ! ! !

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Tutmeister
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Re: Prop axis and brake axis issues.

Post by Tutmeister »

Hi Roger,

Perfect solution for the brakes. Now I get full travel without them coming off part way down. Thank you! :)

My only outstanding issue is how to set up the pitch levers without them moving back so far that the props get stuck in feather.

Chris
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alan CXA651
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Re: Prop axis and brake axis issues.

Post by alan CXA651 »

Hi Chris.
I have all my engines levers setup in FSUIPC , the 4 throttles are mapped individually , this is where it gets odd for the b17 , to get the 4 props and 4 mixtures set for indevidual control differs from that of the throttles you set up the 4 props/mix axis assignments indevidually , just like the throttles , but in the calibration pages they are set up oddly , you go to page 2 and on the prop/mix you tick map to 4 prop/mix pages 4 and 5 tick the no rev box .
Now i have done a test , by running all 4 engines and once warm with rpm set to bottom of green band i slowly pulled each prop lever back , number 4 was the only one i let feather , and was able to unfeather , for a restart .
The prop levers can be pulled back till the tops of the prop control lever knob , is level with the control lever knob of the rpm lock , without going to feather , or stalling the engine.
If you go beyond this setting the engine will feather , let it stop , then pushing prop lever back up unfeathers prop , so you can restart engine.
If in flight the engine is shut down , and she will not come out of feather this way , then i suggest once prop lever is fully fine , try start/mesh , to see if it pumps eng oil into prop spinner to unfeather , i am just going to go for a spin in her to test the feather / unfeather in flight , will use twitch to record event.
Regards alan. 8)

UPDATE:- https://www.twitch.tv/cxa651/v/95544202
The engine number 3 was deliberatly shutdown/feathered , but i could not get it unfeathered , not until i had landed and played around , see video above.
I will be doing another emergency inflight shutdown tomorrow , because it looks like you need to hit the feather button to unfeather the engine for restart in flight , so i need to test this again , so i can get the emergency shutdown/restart proceedure correct , you never know when you will need that knowledge.

UPDATE 2 :- https://www.twitch.tv/cxa651/v/95570455
A successfull inflight engine shutdown / feather / restart , also severe crosswind takeoff/landing at KBFI.
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alan CXA651
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Joined: 15 Mar 2016, 08:23

Re: Prop axis and brake axis issues.

Post by alan CXA651 »

Hi.
Today i did a training flight , to assertain the correct restart needed , after an inflight shutdown and feathered engine.
I now have a method for the correct restart/unfeather proceedure , the video is about 2.5hrs , i managed to shutdown , and restart all 4 engines one at a time , first 2 engines i did not know the correct proceedure , but still managed to get them restarted , the 3rd engine i had the correct proceedure , 4th engine confirmed the proceedure.

before engine restart checks

1. check throttle idle
2. check prop lever in feather
3. check fuel mixture lever in cutoff
4. check fuelpump off
5. check featherbutton not pressed
6. check engine fuel valve closed
7. check ignition off

now for unfeather proceedure

1. eng fuel valve open
2. eng feather switch pressed
3. eng fuel pump on
4. eng mixture lever auto lean
5. watch prop to confirm it moves out of feather position slightly
6. move prop lever to fine position check prop moves to fine
7. engine ignition on
8. throttle lever slightly open
9. select engine fire switch
10. select engine primer one squirt
11. press starter
12. count 10 seconds then engauge mesh
13. once engine runs position proplever to match other engines
14. open throttle slowly to man pressure 20 , turn fire and primer to off position
15. watch cyl head temp wait till temp is 50 min
16. move throttle fwd to man press 25
17 watch cyl head temp wait till 100 min
18. move throttle to man press 30
19. wait till cyl head temp gets to green band
20. adjust throttle to match other engines

https://www.twitch.tv/cxa651/v/95667833
regards alan. 8)
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WB_FlashOver
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Re: Prop axis and brake axis issues.

Post by WB_FlashOver »

My last accidental feathering was about 15 miles out on Right base at 2,000 AGL. A very challenging couple of minutes. I developed a run-a-way turbo and instinctively pulled throttles back when I saw extreme MP on one engine. RPMs were aready at 1500 due to descending into a valley. A knee-jerk reaction got me in a predicament. I got them un-feathered by shutting each one down individually and restarting it.

The only way I've been able to get them out of feathered state is through normal start procedures with the exception of pushing the feather button directly after meshing engine starter. You gotta have engine oil pressure to alter prop pitch.

As far as not getting them into the feather state, I still have no answer for you except to watch very carefully your power settings. Very important!

Cheers
Roger
-- Fly Well, Be Nice, Have Fun ! ! !

Z390 FTW | i9 9900K @ 5.2 | 32GB 3333 CL14 | 3080 Ti FE
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alan CXA651
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Joined: 15 Mar 2016, 08:23

Re: Prop axis and brake axis issues.

Post by alan CXA651 »

Hi Roger.
I know how far you can move them down without feathering , see my videos as i do a pre departure check of mags/props , as per a video i saw of a real b17 doing same checks , prior to entering runway , i have my controls setup in FSUIPC in the main , some are setup in a2a configurator.
I have CH yoke/rudder peddles and 2 CH quad throttles , i will have to remember to post my control setup , so others can try if they like.
Also i have only shut down an engine , that i was concerned about , i have never needed to restart it , the eng in question was giving a lot of oily smoke , yet all inst showed nothing untoward , so i shut it down , and landed with it feathered,the hangar after the flight showed a cylinder gone and 2 or 3 badly damaged , so the shut down was the right thing to do as it saved a bigger repair bill.
regards alan. 8)
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