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CockpitBuilders.com - Main => Builders Discussions => Topic started by: jackpilot on May 03, 2017, 10:50:50 AM

Title: 757 TQ wiring
Post by: jackpilot on May 03, 2017, 10:50:50 AM
Just got my 757 TQ Levers
Figuring out the wiring with a multimeter
(http://imagizer.imageshack.us/v2/xq90/923/ibpcrh.jpg)

Appears that Microswitches for the TOGA are always on, and off when button is pushed. ???
Switches wires for reverse and A/T do not respond to contact test.

I just tried on one lever, maybe some wires are interconnected ?


Jack
Title: Re: TQ wiring (Bernard?)
Post by: bernard S on May 03, 2017, 01:52:32 PM
hi JP   i am not really your huckleberry for this one... Matt is your man as he has that TQ 
Title: Re: TQ wiring (Bernard?)
Post by: jackpilot on May 03, 2017, 02:47:20 PM
Do you mean Matta757 or Matt Ford


Jack
Title: Re: TQ wiring (Bernard?)
Post by: bernard S on May 03, 2017, 06:14:37 PM
matt wull reach out to you  :)
Title: Re: TQ wiring (Bernard?)
Post by: Nat Crea on May 04, 2017, 12:01:14 AM
Quote
Appears that Microswitches for the TOGA are always on, and off when button is pushed.

Nothing wrong with that Jack. Just assign "off event" as your "on"

A/T Disco is a bit worrying, But your Reverse levers should be connected to a Pot not switch as in the NG?

Nat
Title: Re: TQ wiring (Bernard?)
Post by: tomenglish2000 on May 05, 2017, 04:30:52 AM
Hi Jack.

The AT Disco switches are not independent. The A/T Disengage CMD signal goes from the depressed Disco switch through the unpressed Disco switch.

When the switches are both not depressed, an A/T Disengage reset signal is passed through the switches to the TMC (Thrust Management Computer).

These signals are grounds.

Nat, on the 757/767 the reverse levers drive the normal throttle linkage back below the forward idle position. There is no separate reverse linkage. The forward lock is integrated into the levers themselves.

Hope that helps Jack.

Tom.
757/767 Sim Builder.
Title: Re: TQ wiring (Bernard?)
Post by: jackpilot on May 05, 2017, 10:14:31 AM
It does indeed..
I have it figured out but the reverse microswitch
I located the switch (sandwiched in between the casing but it is not physically activated by the reverse lever, like something was missing.
Besides Could you tell me what these two guys are for, they do not move when the reverse lever is cycled, should they ?

 (http://imagizer.imageshack.us/v2/xq90/923/9lyopY.jpg)
Jack
Title: Re: TQ wiring (Bernard?)
Post by: tomenglish2000 on May 05, 2017, 10:31:31 AM
Hi Jack,

Happy to help.

Those two little things are the lever reverser locks. When you pull the reverser lever up those pop out and hit against a piece of guard metal.

These serve two functions,

When the regular levers are forward of idle, they hit against the guard metal and prevent you from pulling the reverse levers. Otherwise the throttle linkage would reduce throttle away from the main lever position.

When the forward levers are in idle, they extend behind the rear of the guard metal when pulling the reverser levers and that prevents you from pushing the main levers forwards while the reverser is deployed. The forward levers are locked in the idle position by this until the reverser levers are stowed.


I am not familiar with the reverser switches. Can you post a picture? The only ones I know of are in the AT microswitch pack but I think that is on part of the throttle linkage below the floor near the clutches.


Tom.
757/767 Sim Builder.
Title: Re: 757 TQ wiring
Post by: jackpilot on May 05, 2017, 12:57:45 PM
REV switches are inside the lever (arrow)
Do you know the use of the "skate" circled in red on the left (friction device)?
Thanks for your input
(http://imagizer.imageshack.us/v2/xq90/924/g3zone.jpg)
Jack
Title: Re: 757 TQ wiring
Post by: tomenglish2000 on May 05, 2017, 01:24:43 PM
Hi Jack,

I completely forgot those switches were there! I believe they are independent. Not sure why they arent working. Maybe the metal arm has come off them or the switch has failed or something. They should just work. I will have a look at my set over the weekend to see what mine do.

The "skid plate" is actually designed as cam that pushes a follower when either reverse lever is moved up to reverse idle and onwards to full reverse. The follower actuates a lever that raises the spoiler handle out of its down detent so that the spoiler motor can deploy them. This ensures spoiler deployment even if they were not armed.

Phil has some shots from his throttle that show this:
https://www.flickr.com/photos/project75/5647285859/in/album-72157627311717046/ (https://www.flickr.com/photos/project75/5647285859/in/album-72157627311717046/)
https://www.flickr.com/photos/project75/5647841532/in/album-72157627311717046/ (https://www.flickr.com/photos/project75/5647841532/in/album-72157627311717046/)
https://www.flickr.com/photos/project75/5647278813/in/album-72157627311717046/ (https://www.flickr.com/photos/project75/5647278813/in/album-72157627311717046/)

Tom.
767 Sim Builder.
Title: Re: 757 TQ wiring
Post by: jackpilot on May 06, 2017, 01:47:43 PM
I sorted the Reverser switch issue. Careful de-assembly and cleaning.

Do you Guys know where i can get a proper tool with prongs to loosen that bolt, I do not have that in my workshop and does not even know its proper name...
Title: Re: 757 TQ wiring
Post by: Garys on May 06, 2017, 02:18:40 PM
Look for Castle nut socket. You can by them online. I saw  a guy in the process of hacking a impact socket to fit these type of nuts but I didn't didn't stick around long enough to see if it worked.

Cheers
Gary
Title: Re: 757 TQ wiring
Post by: jackpilot on May 06, 2017, 02:41:51 PM
 ;)
Thank you
That bolt locks the axis of the TQ levers and there is one smaller on the other side.
I suppose it is not metric
Where should I measure  to buy the proper size.
Title: Re: TQ wiring (Bernard?)
Post by: matta757 on May 06, 2017, 05:18:46 PM


The AT Disco switches are not independent. The A/T Disengage CMD signal goes from the depressed Disco switch through the unpressed Disco switch.



Tom,

Not questioning you on this as it certainly sounds like that should be the case, but the way I've wired my AT disconnect switches they ARE independent of each other, each switch has its own input on my BUO836X board and they are NO configured (meaning you must press them to create the event, opposite of the NC TOGA switches).

I don't know why this is the case with mine, but Jack when I first got my TQ I had ZERO information to go off of for the wiring and just played around with the wires until I found a combination of wires that worked. I got my TQ first of everything I have and was before I had any concept of how to wire using the cannon plugs that they use in real planes, and so I had just cut the plug off and played around with the wires until I found the right combo.

Sorry I can't be of my help. Tom has explained everything else about the inner workings of the TQ in a spot on way, so I have nothing else to add.

Jack- can I ask why you want to take that castle nut off? That holds the whole thing together and makes installation of the levers quite easy, is there are reason you want to separate them?

Matt
Title: Re: 757 TQ wiring
Post by: matta757 on May 06, 2017, 05:23:11 PM
Hi Jack,

I completely forgot those switches were there! I believe they are independent. Not sure why they arent working. Maybe the metal arm has come off them or the switch has failed or something. They should just work. I will have a look at my set over the weekend to see what mine do.


Ok so I feel like I should know this, and feel like an idiot for not, but what exactly are those switches even for? I don't have them wired in my sim at all, what's the function of them in the real plane?

Matt
Title: Re: 757 TQ wiring
Post by: Garys on May 06, 2017, 08:18:34 PM
initiates the thrust reverser control system
Title: Re: TQ wiring (Bernard?)
Post by: jackpilot on May 07, 2017, 05:53:36 PM

Jack- can I ask why you want to take that castle nut off? That holds the whole thing together and makes installation of the levers quite easy, is there are reason you want to separate them?

Matt
Hi Matt
First idea was to separate them to install a new axle allowing a clutch setup for friction, same as my actual TQ which has worked flawlessly so far.
(http://i24.photobucket.com/albums/c29/jackpilot/PhotoNIKONAxlein.jpg)
Just an idea though,
How did you manage that friction factor because right now they revolve loose on the axle?
Jack
Title: Re: 757 TQ wiring
Post by: matta757 on May 07, 2017, 06:41:22 PM
Jack,

Well since I bought my real 757 sim, I now have the clutch pack that gives the levers their tension. https://flic.kr/p/EDtKLg (https://flic.kr/p/EDtKLg)

But before I had that, I built a make shift clutch pack based on Edoardo and Valerio's design. You can check out Valerio's flickr page for pics... https://www.flickr.com/photos/78279080@N04/albums/72157650785641286 (https://www.flickr.com/photos/78279080@N04/albums/72157650785641286)

The slip clutches are attached to the arms, which are attached to the throttle rods that attach to the lever arm. Whatever you do, I would strongly advise against taking the levers apart. The way they are built and put together means a rock solid feel, there is ZERO play between them. If you separate them, all bets are off and you could end up with lateral play in the levers.

Matt

Title: Re: 757 TQ wiring
Post by: jackpilot on May 08, 2017, 09:12:57 AM
Thanks for the info, I will check it out carefully.
I thought of my original design (as per above) because it has no play either and works without rods or offset mounts.
Will take my time anyway..
Jack
Title: Re: 757 TQ wiring
Post by: jackpilot on May 08, 2017, 01:37:34 PM
Matt:
This X shaped bracket:
(http://imagizer.imageshack.us/v2/xq90/923/EBR3ET.jpg)

is used to hold the lever assembly inside the TQ I guess.
I have just one on the FO side
 would you or someone  have one available?
Title: Re: 757 TQ wiring
Post by: matta757 on May 08, 2017, 01:59:56 PM
Jack,

Yes that bracket mounts to the walls of the TQ. But there is one on both sides. I do not have a spare unfortunately. If you have no play on your design then it should be fine, I just know that from my own experience, treading lightly and trying to keep things in the OEM condition as much as possible.

Matt
Title: Re: 757 TQ wiring
Post by: jackpilot on May 08, 2017, 02:24:39 PM
Agreed.
Title: Re: 757 TQ wiring
Post by: mickc on May 08, 2017, 04:51:24 PM
I just know that from my own experience, treading lightly and trying to keep things in the OEM condition as much as possible.



Where were you a week ago ? :laugh: :laugh: :laugh:



Title: Re: 757 TQ wiring
Post by: matta757 on May 08, 2017, 08:47:58 PM
I just know that from my own experience, treading lightly and trying to keep things in the OEM condition as much as possible.



Where were you a week ago ? :laugh: :laugh: :laugh:

I saw this picture in your other thread and was floored. Amazing work. I am assuming you took care to document everything. I didn't go quite as in depth (down to every little part) but I did disassemble and clean everything...

Matt
Title: Re: TQ wiring (Bernard?)
Post by: tomenglish2000 on May 09, 2017, 06:59:13 AM
Not questioning you on this as it certainly sounds like that should be the case, but the way I've wired my AT disconnect switches they ARE independent of each other, each switch has its own input on my BUO836X board and they are NO configured (meaning you must press them to create the event, opposite of the NC TOGA switches).

Hi Matt,

Checked the WDM carefully and found the following:

Both the left and right A/T Disco switches have a path direct to ground for the Disco signal and so will work regardless of the position of the other switch. There is only one input to the TMC for this ground signal though, so if you wish you can put them together on your BUO836X and save an input. Sorry for the confusion.

The Disco reset signal is wired through BOTH switches to make certain that if either switch is pressed, the reset signal cannot be received by the TMC.

The reverser switches are the L / R THRUST REVERSER CONTROL switches (78-34-01). Module 985 (Thrust Lever Assembly). Left one is S5. Right one is S6. As Gary says, they initiate the stow/deploy of the reversers (and deploy/stow happens if a load of other inputs such as air/gnd relays, A/T switch pack inputs, DC bus sense, etc are present). For the simulation world, I don't think they will be used, no current software looks at this stuff. PSX simulates these inputs for the 747 based on lever angle anyway.


Thanks.
Tom.
Title: Re: 757 TQ wiring
Post by: jackpilot on May 09, 2017, 08:10:25 AM
Precious info even if this logic is of limited use in our simulation softs.
Just one (more) question, which will help interfacing:
The reversers levers are
 1) Full forward (no action) switch closed
 2) Pulled backwards to mid position (cam lock) (switch opens)
 3) Can be pulled full backwards (switch still open)

What's happening on the real plane ?
1) Stowed
2) Deployed
3) proportional thrust ?



Title: Re: 757 TQ wiring
Post by: tomenglish2000 on May 09, 2017, 08:59:22 AM
Hi Jack,

Thats right.

The reverse levers fully down and the forward levers fully back is forward idle.

The reverse levers up to the first detent is reverse idle. This activates the switch which if all the conditions are met tells the reverse doors to open. The engine remains at idle thrust. The reverse lever is prevented from raising past reverse idle until both reverser halves reach at least 60% of full travel, the interlock then releases the lever. The reverse lever can now be raised up to full reverse, this just controls how much thrust the engine produces.

Then the process is reversed. Moving the levers to reverse idle from full reverse (or an intermediate position) does nothing. Moving the levers to fwd idle commands the reverser halves to stow.

There is no interlock to prevent the fwd levers being applied while the reverser halves are still deployed.

Figures above quoted for CFM engine with EEC.

Thanks.
Tom.
Title: Re: 757 TQ wiring
Post by: bernard S on May 09, 2017, 09:00:46 AM
as in the pm i sent you ????  if you are wanting full interoperability per the aircraft you will require the thrust reverser interlocking actuators and some sort of clutch try to source the P box for such it may make it easier .. I do not know if your software supports such beasts in my 74 I have full TQ function so you may have to write some sort of add on wish i could be of more help but my 73 75 76 knowledge is strictly limited  to basics  those basics being  push fwd  it goes faster pull back it goes slower
Title: Re: 757 TQ wiring
Post by: Garys on May 09, 2017, 07:16:45 PM
"Then the process is reversed. Moving the levers to reverse idle from full reverse (or an intermediate position) does nothing. Moving the levers to fwd idle commands the reverser halves to stow.

There is no interlock to prevent the fwd levers being applied while the reverser halves are still deployed"


Actually there in an interlock that will inhibit the fwd motion of the levers until the reverser sleeves are completely stowed.  That means the reverse thrust levers have to be fully down and the amber REV on the Engine display must be out before the system will allow you to move the throttles fwd. Also the same when applying reverse thrust. When you move the reverse handles to the idle position the reverser sleeves must be in fully deployed position and you must wait until the REV goes from amber to green on the engine display before the interlock will allow you to move the handles up to full reverse position.

Title: Re: 757 TQ wiring
Post by: tomenglish2000 on May 10, 2017, 04:06:37 AM
Hi Gary,

Thanks for that. I was in two minds about posting that about the lack of a forward interlock, I couldn't find it in the books so thought it didn't exist. Maybe I was looking in the wrong section. It didn't make sense to me though.

Do you know how "closed" the reverser sleeves have to be to remove the interlock? On the CFMs with EEC the reverse interlock is removed at 60% of reverser sleeves movement.

Thanks.
Tom.
Title: Re: 757 TQ wiring
Post by: Garys on May 10, 2017, 04:48:00 AM
They need to be fully stowed. If the translating sleeves are in transit the interlocks are engaged.

What model CFM engine do you have the notes on?

 
Title: Re: 757 TQ wiring
Post by: tomenglish2000 on May 10, 2017, 05:02:12 AM
Hi Gary,

It's a CF6-80C Series. The AMM says that once the sleeves are open 60% of full travel the reverse interlock disengages. Thats for EEC controlled engines. The EEC will then (proportionally?) limit the reverse thrust until open. For non-EEC controlled engines (doubt there are many around these days) the interlock disengages proportionally between 76% to 95% of the full travel.

I don't have any information on other engine types.

Tom.
Title: Re: 757 TQ wiring
Post by: Garys on May 11, 2017, 01:11:55 AM
That makes sense for the CF6 as the Central Drive Unit is air driven by aircraft pneumatics. On PMC (Cables) CF6 engines the interlocks are in the pylons. Fadec version of the CF6 has the interlocks in the throttle quadrant. Both types have EEC but on the PMC type the EEC is supervisory only.
Title: Re: 757 TQ wiring
Post by: jackpilot on May 11, 2017, 02:25:48 PM
Are you Guys talking about the 757 or the 737 ?    ???
Title: Re: 757 TQ wiring
Post by: Garys on May 11, 2017, 07:00:19 PM
I was originally talking of the 757. The GE CF6 engine that Tom was talking about is the for the 767.  The throttle quadrant is pretty much identical including the switches that you wanted info on and how it worked on the aircraft. There are slight differences between the aircraft when the interlocks engage/disengage but the thrust reverse sleeves move so fast that you don't really see much of a delay unless your specifically looking for one.

Cheers
Gary