B737 Throttle Quadrant conversion

[FredK]

My project over the winter was conversion of a 737 throttle quadrant that I acquired last fall.  I first must thank both Rob and Scott here for the invaluable information that they had posted previously on this subject.  I incorporated most of that guidance in my conversion project but also did some things differently which I would in turn like to share here.

This was my starting point. A TQ removed from N379UA, a United Airlines 737-322 vintage 1991:



Note that the undercarriage support assembly was left intact when the TQ was removed. This was an advantage since by trimming off the bottom part with a Sawz-All I had a sturdy platform to mount my throttle motor drive assembly:



Some more pictures of the finished product:





This is a photo of the overall throttle drive assembly:



I used two inexpensive high torque/low rpm(15) motors from RobotZone coupled to slip clutches (#S98CA6MMOC320838 from SDP/SI). These slip clutches are identical to the ones from Polyclutch reported here previously (I believe they are sourced from the same manufacturer). The string pots are as suggested previously (Unimeasure PA-LX-10).

Note that I used a 6mm-to-8mm coupling to connect the 6mm motor shaft to the 8mm slip clutch shaft. I supported the drive shaft on a pillow block to avoid any shaft deflection or bending.  The result was a very solid support for the drive:



I used a bearing pulley system as a guide for the string pot mount to minimize angular distortion:



The following shows the pulley mechanism I fabricated for the throttle levers:



I used slide pots for my flaps and spoiler (Bourns 10K Thin B Taper).  In each case they are connected to push rods that are screw mounted into the sides of the respective wheels. The following shows the external slide pot mounting for the flaps and the servo mounting for the spoiler:





The following shows the spoiler slide pot and servo assemblies. There was a lot of trial and error involved here to get the two assemblies to function together without binding.  The result turned out very well though:



The following is the trim wheel motor mounting:



The following is the servo mounting for the trim gauges:



I used a magnetic catch approach for fashioning my parking brake switch using the existing connecting rod. Such required epoxying a metal plate onto the rod between two screw slip bushings:



I plan to use the Open Cockpits USB DC Motors Plus board as an interface and have completed the wiring:



My next task is to do the SIOC programming.  I have some starting points but this is my first crack at doing such.....any help and guidance applicable to a motorized TQ would be much appreciated.

Overall I am very pleased with my project.  I took the time to disassemble and strip off all the old layers of paint and to spray paint component parts anew. So everything looks very clean.  I am particularly pleased with the feel of the throttle movement....there is virtually no play or looseness in the movement.  It all has a high quality feel.  I also soldered in replacement bulbs for the light plates so all that is in working order.  Those miniature bulbs cost an incredible $10 each from a certified Boeing supplier...there are 4-8 required for each light plate and about half were burnt out!

Fred K

[blueskydriver]

Hi Fred,

Nice Work!

Will you please post a complete part list with part numbers, where you purchase them and the price for each item? That way others; including myself, can follow your plan much like Scott and Rob's. Currently, my TQ is not motorized, but it's on "the to do list" and moving up the list rather quickly. With your help, it'll be my next project from that list...

John

[Jetcos]

Nice work Fred, worth the wait after the previous post about how to post pictures.   

Thanks for posting.

[N737AG]

Fred :

Very nicely done. Some nice solutions that got me thinking about the positioning of my motors.

Axel

[Nat Crea]

Great work Fred!

I love how there are so many ways to skin a cat, and the use of the original pulleys.

Nat

[XOrionFE]

Looks great Fred!   There ain't nothing like having the real thing and knowing how it works along with your own engineering so that you can maintain it.  Fantastic job.  I hope someday to be able to visit and fly it!

Scott

[Sam Llorca]

Great work Fred, AWESOME!!!

[sagrada737]

Hello Fred,

Outstanding job on completing the hardware modifications for your motorized TQ - nice work!  I appreciate the host of photos showing much of the detail for your mods.  Especially nice is the job you have done in organizing your various assemblies and wiring details to the OpenCockpits DCMotorsPlus card.

I wish I could help you with the SIOC challenge, but I am new to this language myself.  Hopefully folks with more hands-on experience with SIOC will chime in.  I assume that in your initial testing of the DC and servo motors, that you were able to test these functions.  How did you go about accomplishing that task, as well at testing the Inputs and Outputs?  Comments on this would be interesting as the DCMotorsPlus documentation is difficult to understand.

Is is possible to ask for a few more photos showing close-ups of the wiring to the DCMotorsPlus card?  Thanks.

Anyway, congratulations on a fine job of modifying your TQ.  I am sure it will be a great addition to your Sim Project.

Mike

[fsaviator]

Very nice!  Great rundown!

[Jon Boe]

Hi Fred,

Very nice!

Post a video of it in operation when you get the software portion completed.

Cheers,

Jon

[fordgt40]

Fred

Here is a copy of my throttle assembly sioc file with offsets for Sim A and using an OC DCmotors card and servos card. It should give you a head start, but you will need to modify it to suit your hardware. The file is in .doc format to allow coloured comments, so you will need to change it to .txt via notepad.

Regards

David

[FredK]

Fred

Here is a copy of my throttle assembly sioc file with offsets for Sim A and using an OC DCmotors card and servos card. It should give you a head start, but you will need to modify it to suit your hardware. The file is in .doc format to allow coloured comments, so you will need to change it to .txt via notepad.

Regards

David

David -

Much appreciated!

Warren also passed on his script.  I do have a general knowledge of software programming but this is my first crack at SIOC so this will give me a headstart on things.  I figure it is about time I learned about SIOC anyhow.  I'm even sort of looking forward to it as a challenge.  Hopefully that will not transition into frustration once I get into it.

Fred

[jetpilot]

Fred,
Thank you for this post.
Currently my TQ is completely apart, so your post give me some additional ideas, besides the ones that I have learned from Scott.
I have a question (And may be I am missing something here):
You installed a motor to move the trim wheels, but how does flight simulator knows the position of them? don't you need a potentiometer or something to feed back this info into the sim?
Thank you

Roberto C

[FredK]

Fred,
Thank you for this post.
Currently my TQ is completely apart, so your post give me some additional ideas, besides the ones that I have learned from Scott.
I have a question (And may be I am missing something here):
You installed a motor to move the trim wheels, but how does flight simulator knows the position of them? don't you need a potentiometer or something to feed back this info into the sim?
Thank you

Roberto C

Roberto -

The simple answer is that FS never really knows the position of the trim wheels.   The programming is simply set up to move the wheels in the appropriate direction and speed when FS is calling for elevator trim movement and when applying electric trim adjustment.  Since no one actually uses the wheels for adjusting trim this is for visual eye candy effect only.  Not worth the effort to figure out a way to have it operational as an input or to correlate such exactly. Would be difficult to do.

Fred

[sagrada737]

Hello Fred,

You mentioned that you were just beginning to explore using SIOC for control of your newly configured motorized TQ.  Your choice of using the OpenCockpits (OC) USB DC Motors Plus card seems appropriate, but unfortunately, the documentation is a bit sketchy. 

Below are a couple of links that you might find helpful for applying SIOC programming to this type of OC USB DC Motor Card. 

This information does not exactly reference the USB DC Motors Plus card that you are using, but it does apply to OpenCockpits DC Motors cards in general.   The associated SIOC references within this information may be helpful to you.  Of course, the SIOC TQ code that David posted is another very useful reference - especially to help one understand the logic he used to apply the SIOC coding - no sense in reinventing the wheel.  The Mutley's Hangar link is interesting and a practical review of the DC Motors card that is easy to understand.

Hessel Oosten's excellent USBDC motors guide (.txt file):
http://www.mediafire.com/?4b0vtg59w7b24bz

Mutley's Hangar review of OC's DC Motor Card   
http://www.mutleyshangar.com/reviews/jack/dcm/dcm.htm

Hope this helps to move progress forward on your motorized TQ project.  By the way...   As you most likely already appreciate, it is always important to add comments to each section/line of your SIOC code describing exactly what is being done within a function/operation.  This makes it easier to understand your code at a later point in time, and easier to communicate your code to someone else.

Mike

[FredK]

Thanks Mike!

I had not seen those references.

Much appreciated!

Fred

[Flight_Master]

Hi Fred,

Great job on interfacing the TQ. I'm working on mine as well, but I kept the white base that can be seen on your first picture and that is where I placed all the guts. Please correct me if I'm wrong but the way you placed your DC card, motors etc., you will not be able to install orginal pedestal/radio box unless you have an alternative? If you would like I can send you few pictures showing my solution. It was a quite tight fit but doable.

I'm also looking for help with SIOC script as I bought DC motor plus card specifically for the throttle but I'm struggling with the code. I hope your thread will give the community lots of information on how to do it. Big thanks to other that are always willing to help.

BTW if you need bulbs for the light plate, you can get them at many location for less than a buck. Let me know if you need more info.

Best,

Piotr Niedzwiedz

[N737AG]

Piotr

I think we all would love to see your pictures. Also the reference for the bulbs would be very useful for many of us.

Thank you

Axel

[FredK]

Hi Fred,

Great job on interfacing the TQ. I'm working on mine as well, but I kept the white base that can be seen on your first picture and that is where I placed all the guts. Please correct me if I'm wrong but the way you placed your DC card, motors etc., you will not be able to install orginal pedestal/radio box unless you have an alternative? If you would like I can send you few pictures showing my solution. It was a quite tight fit but doable.

I'm also looking for help with SIOC script as I bought DC motor plus card specifically for the throttle but I'm struggling with the code. I hope your thread will give the community lots of information on how to do it. Big thanks to other that are always willing to help.

BTW if you need bulbs for the light plate, you can get them at many location for less than a buck. Let me know if you need more info.

Best,

Piotr Niedzwiedz

I will be using the "home built" pedestal panel that exists in my current setup.  I will simply install a removable shelf over the throttle lever drive mechanism of the TQ to protect it from any hanging wires from the NAV radios etc.  By having the shelf removable will provide easy access to anything that needs servicing.  The position of the OC interface board is low enough that it clears the Fire Handle panel in the pedestal.

I do have the original pedestal panel for this TQ as shown in the first picture.  It could be made to work in my case but would require significant cutting out to achieve the fit.  The net is that I am happy with my current pedestal panel that is a pretty good replica and that is customized in some other ways for my setup.  So it is the easiest way to go.

I'm sure others would be interested in seeing your solution though.

BTW....I do have the original pedestal base and am willing to sell if anyone is interested.  It is a "three bay" which is rare to find.

Fred

[blueskydriver]

Fred sent you PM.

John

[727737Nut]

Nice work Fred!! Nothing beats the real parts!

Rob

[Flight_Master]

Piotr

I think we all would love to see your pictures. Also the reference for the bulbs would be very useful for many of us.

Thank you

Axel

Axel,

These bulbs are made by JKL Components. Part # 6832. I bought these bulbs to fix light plate on my TQ as well as to backlight other panels. You can find them on Mouser.com part # 560-6832


Piotr

[Flight_Master]

Fred,

Here are few photos of how I interfaced my TQ using original base. I tried my best to use original cables and pulleys, so there is a smooth operation without any interference as we all know it is a quite tight fit. The only thing I haven't finish yet is the trim wheel and speedbrake motor . Also I spent considerable amount of time trying to figure it out pin outs on the bottom of the throttle so I didn't have to run new wires to switches and backlighting. I have a list that I can make available to anyone. Anyway here is my setup. 


On the bottom I built extension platform to accommodate motors.


Here is general view how I routed cables for the throttle levers. In blue, location of original pulleys.


Close up of pulleys at the bottom base. You can also see and actuator (black) used for parking brake.


DC motor and string potentiometer


Flap lever cable. Original pulley bracket. I removed the pulley and I used sprocket instead. Potentiometer connected directly to sprocket.


Regular servo connected to trim indicator arm. Works very smooth with Prosim.



Here is the DC motor card with few other things. Installed at top of bottom base. Very tight fit in a two bay pedestal but it works.


I hope this helps little bit.

Piotr

[FredK]

Piotr -

Nice Work!

It is clear that there are many ways to skin this cat!

Fred

[N737AG]

Piotr

Thanks for the bulb info and of course for the pictures.

I am trying to make something similar as you did. However, since my platform is from a real plane, I can not have the DC motors standing out. So there I have a real challenge.

Thanks again

Axel