[For Sale] 747-400 Throttle Quadrant with Pedestal OEM

[Raf]

Up for sale - very rare and and in good condition, original 747-400 TQ. Complete with the Fuel Control Panel and all the switches. Very clean. Everything works as intended, levers move smoothly, A/T disconnect and TO/GA levers and microswitch pack assembly. Pulling TR levers locks the main thrust levers at idle, and elevates the speed brake lever. Flap lever is hooked up to the RVDT assembly. Pedestal has original DZUS rails.

[ Update 8/23 - the throttle is now SOLD ]

[Avi]

Does pic 29 show the flaps lever RVDT?

Thanks,

[Raf]

Does pic 29 show the flaps lever RVDT?

Yes, that's the one.

[Jack love 744ERF]

So good! She looks much newer then mine. My TQ is from G-BNLT. It looks old. I found that all the British airways cockpit looks old. The edge of the TQ looks green already. But they just don’t like repaint.

[Chris Kilroy]

Wow, that looks incredible. Practically brand new. Question: How difficult would it be to interface something like this (including the throttle/speedbrake motors) with PSX? My motorized FDS TQ with trim indicators does a fine job but having something like this would be much cooler. Thanks!

[Roddez]

Question: How difficult would it be to interface something like this (including the throttle/speedbrake motors) with PSX?

Hi Chris,

It is possible, but there would be a bit of work involved in this.

The throttle motor gearbox is missing from the quadrant so you would need to either find a new gearbox or engineer a direct drive alternative.  The original gearbox is a worm gear arrangement and the original motor also uses a planetary arrangement to provide gearing to move the throttles.

All of the spoiler handle magic (Deploy, stow, flight detent lockout & measurement) happens under the floor of the cockpit so you would need to design and build suitable replacements.  The handle in the cockpit is linked via a pushrod to the underfloor system.

You would also need to build throttle position sensors.

Have a look a the work that Hans in Austria has done with his centre pedestal for an idea of the work involved.
http://www.b747-400.net/php/slider_tq_thrust.htm
http://www.b747-400.net/php/slider_tq_flaps.htm

[Raf]

Look at pic #27. That's the throttle brake assembly. There are total of 5 brake units on that shaft. One for each lever plus at the end there's one for AT motor/gearbox. They work pretty much like the brakes in your car. You see those big castle nuts... you can adjust the friction of each lever by turning those. Maintenance manual specifies exact figure for "knob force". There's nothing special in the gearbox, it's just turning the shaft at about 1.5-1.8 RPM and moving all 4 levers the the same time (levers are attached to the shaft by those friction brake packs), so even if you grab a throttle lever while it's moving you won't get injured - it will just stop. You will overcome the friction and stop the lever, but any other lever (that you aren't holding) will keep moving. Furthermore if you leave the motor running and the shaft keeps spinning even when the lever reached their max - nothing will happen. The motor will overcome the friction and will just keep spinning the shaft. I think Boeing did a pretty good job with that.

You'd attach some sliding pots to each lever brake pack to get the position info and figure out how to spin that shaft at low RPM. Aliexpress has some hi-torque low RPM gearboxes 12 and 24V DC really cheap. CNC a spline adapter for the shaft and hook it up to a card that can drive a DC motor.

[Chris Kilroy]

Thanks guys. That sounds like a major exceedance of my skill set. The FDS kit will just have to do!

[Jack love 744ERF]

I am sorry I may be  A little bit out of topic. My TQ  does not include the gearbox neither.  I think most of the airline would take that off for spare used.  I am very lucky.  I found my gear box at a very low price. Some questions:
1.May I use the original motor to interface?
2.Many friends are not using the original one but a DC motor. Why?
3.Any suggestions to interface it? I already interface the input, including all four levers, SPD BRK, Flap lever, and all the switches with a Leo bornard card. I don’t know how to motorized any levers...
4.Can I interface the “motorized” function with SimStack? Or any other suggestions?

Jack

[Raf]

The main reason against using the original motor are the power requirements. It runs on 115V AC 400Hz. You can't use your home grid 50/60Hz and power supplies capable of delivering that are really expensive. With the OEM Gearbox you can easily run it on 12V DC motor at around 600rpm.

[Roddez]

4.Can I interface the “motorized” function with SimStack? Or any other suggestions?

Hi Jack,

Yes you can use SimStack for this purpose - I will send you an email with details.

Rod.

[BALDO]

Good afternoon Raf

Is this set sold ?
if not can we discuss by mail ?
You can writte me at jclaude.balducchi@gmail.com

Many thanks To you.

Jean Claude

[Jack love 744ERF]

The main reason against using the original motor are the power requirements. It runs on 115V AC 400Hz. You can't use your home grid 50/60Hz and power supplies capable of delivering that are really expensive. With the OEM Gearbox you can easily run it on 12V DC motor at around 600rpm.

Oh understood. Yes I think it is not difficult to make a mount a 12v motor with the gearbox.
One more question. What rpm 12v DC motor I should use with the original gearbox? Thank you.

[Jack love 744ERF]

Good afternoon Raf

Is this set sold ?
if not can we discuss by mail ?
You can writte me at jclaude.balducchi@gmail.com

Many thanks To you.

Jean Claude

Go! Please don’t hesitate. I can tell this is very new and clean. Much better then mine. Ha ha. I feel very fun to work the interfacing job with this fantastic OEM TQ.

[Jack love 744ERF]

4.Can I interface the “motorized” function with SimStack? Or any other suggestions?

Hi Jack,

Yes you can use SimStack for this purpose - I will send you an email with details.

Rod.

Thank you, Rod.

[Raf]

Good afternoon Raf

Is this set sold ?
if not can we discuss by mail ?
You can writte me at jclaude.balducchi@gmail.com

Many thanks To you.

Jean Claude

Check your email Jean...

[Raf]

Oh understood. Yes I think it is not difficult to make a mount a 12v motor with the gearbox.
One more question. What rpm 12v DC motor I should use with the original gearbox? Thank you.

Maintenance manual states (Chapter 76 multiple locations ie. Page 208), that the servomotor moves the levers from idle to full forward in 5 (five) seconds. Levers TLA (thrust lever angle) range is 50 degrees. So it needs to move 50 deg in 5 seconds, so 36 seconds for full revolution or 1.66 RPM. So the brake assembly shaft needs to move around that speed providing the linkage from the assembly to the levers is 1:1 (it's not but it's really close).

Now from my research the OEM gearbox ratio is 360:1 (360 revolutions of the input = 1 revolution of the output), so you are looking at around 600 RPMs on the input of the gearbox to drive the shaft at 1.66 RPM. Get a motor that can do 800 or a 1000 with the speed controller so you can adjust it so it moves the levers in 5  seconds like the manual states for full realism. Hope that helps.

[Jack love 744ERF]

Thank you so much! It helps a lot!!!

[Jeroen Hoppenbrouwers]

I recall that in the early days of Matt's sim in Sydney, they stripped the gears off more than one gearbox due to the unexpectedly high torques required. So be careful!


Hoppie

[Raf]

I recall that in the early days of Matt's sim in Sydney, they stripped the gears off more than one gearbox due to the unexpectedly high torques required. So be careful!

You can always check if your assembly's friction levels are within specs. Get yourself one of those pull style luggage scales with a digital readout (about $5) and test the forces required to move the levers (at the knob).

- Forward thrust levers should be no more than 3.4 lbs (15.1 Newtons) each through their full range of travel.
- Reverse thrust lever load is 4 lbs (17.8 Newtons) except at the detent - 5.5 pounds - no more than 6.5 lbs

Check if the last brake pack (AT) is not seized due to years of inactivity. If it is - cut the safety wire and loosen up that big nut a little. If the throttle levers are too tight you can do the same thing to adjust them. I'd also check if the gearbox is properly greased as well. Moving a single throttle lever should not cause other levers to move (that's assuming the gearbox is not attached to the shaft). The AT pack friction level should be just enough to prevent the slippage but if it's too tight it will impose unnecessary torque forces on the gearing inside your gearbox. If the forces are not consistent (they change as you rotate the levers) - it's probably a dried up near-solid chunk of 30-year old grease inside the pack that's causing it, or bad bearing in the lever linkage or pack assembly.