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Main => General Discussion Board. => Topic started by: kurt-olsson on October 28, 2017, 12:24:41 PM

Title: Help with yoke construction.
Post by: kurt-olsson on October 28, 2017, 12:24:41 PM
Ok, while saving up for the FDS mip i will start to build my yoke construction.
I was lucky to get hold of the steering boxes and also the rod between the yokes.

I thought i had everything figured out and the previous owner had the canles setup aswell.

I thought the "silver-steel-thing-connection" between the yokes and the boxes was turned 90degrees so it could handle movement in the forward and backward motion with the boxes fixated. But when i look they are turned 90degrees the other way. Does this mean that i will have to fixate the boxes to the rod so they will rotate aswell when i move the yokes forward and backwards?

I have seen lots of constructions but none with original steeringboxes.
What would any of you who have knowledge with the yokes do with my hardware.

With "silver-steel-thing-connection" i mean the steelthing i have holding with my finger.

Really fun to start building the yokes, been waiting for space for 2 years. Hehe


Title: Re: Help with yoke construction.
Post by: XOrionFE on October 28, 2017, 03:05:20 PM
You wont want to bother with those lower boxes.   Remove the tabs and fit a piece of pipe to extend the shaft downward and attach pullys to the extension.  Yes, the pulleys will move with the bottom of te yokes.    See pictures i have posted or take a look at my youtube videos.   

Scott
Title: Re: Help with yoke construction.
Post by: kurt-olsson on October 28, 2017, 10:31:26 PM
Thanks Scott, just wanted to be sure that i was doing the right thing removing the boxes. Your videos is alot of help.
Title: Re: Help with yoke construction.
Post by: kurt-olsson on October 28, 2017, 10:38:00 PM
By the way, how did you make/buy your extension pipe?
Almost all builders have this technique.

I am thinking of some hard plastic tube that has the right measures?

Where did you find this part for your build Scott?
Title: Re: Help with yoke construction.
Post by: Gallie on October 29, 2017, 02:16:30 AM
You are very lucky to own original aileron linkage parts.
The only reason NOT to use the original aileron linkage is because of the lack of sim room height. You would probably need a cockpit floor height of 30/40cm maybe even a bit more.

The connection between the control column and aileron linkage is called "clevis & spade joint"

The aileron drums "boxes" are fixed to the aircraft (cockpit floor), only the control columns moves.

Its not just extending the "pipe" and fitting it with a pulley. You must also design bearing brackets, because of the shear force on the pulleys when the cable is put on tension with the turnbuckles. Without any bearings to support on the extended pipe, the tension of the cable will loosen over time.

Before i had my 737 cockpit, i used original 747 aileron linkage. This meant i needed a 30cm high floor, but it saved me a lot of time designing and building custom aileron linkage.

Michael
Title: Re: Help with yoke construction.
Post by: XOrionFE on October 29, 2017, 04:02:43 AM
Quote from: Gallie on October 29, 2017, 02:16:30 AM
You are very lucky to own original aileron linkage parts.
The only reason NOT to use the original aileron linkage is because of the lack of sim room height. You would probably need a cockpit floor height of 30/40cm maybe even a bit more.

The connection between the control column and aileron linkage is called "clevis & spade joint"

The aileron drums "boxes" are fixed to the aircraft (cockpit floor), only the control columns moves.

Its not just extending the "pipe" and fitting it with a pulley. You must also design bearing brackets, because of the shear force on the pulleys when the cable is put on tension with the turnbuckles. Without any bearings to support on the extended pipe, the tension of the cable will loosen over time.

Before i had my 737 cockpit, i used original 747 aileron linkage. This meant i needed a 30cm high floor, but it saved me a lot of time designing and building custom aileron linkage.

Michael

Excellent point on the bearing brackets at the bottom Michael.     Kurt, if you look at my videos you will see that Inhad tomdo exactly what Michael mentions.   You need bearings at the bottom with a plate and tied to the opposite side so the cable tension cannot cause all to bind up.   Plastic extension tubes will not work.   You need very precise fitting down tubes and a way to apply a bearing.    This all requires custom design and machining work.   Find a local machine shop to help you out.   Again, feel free to copy what I did but take your time...there are many angles and relationships to work out with the mountings.  You also need to make some mounts for the crossovertube bearings that all swivels on.

Even without the streering boxes tou will ultimatly need about 12-15 inches of space under your cockpit floor.  Hopefully your room height will support that. 

Scott
Title: Re: Help with yoke construction.
Post by: Caflyt on October 29, 2017, 05:56:00 AM
When I did mine, I had two solid aluminum rods machined to "press" into the original down tubes then the rod was drilled and tapped to accept a 1/2" bolt which has sprockets attached for the connecting chain. I did add a bearing plate to keep the rod from binding from the tension of the chain.
I don't have any pictures of that however.
I had a 1" square tubing frame welded to hold the entire assembly and used 1/2" long bolts at either end which fit into pillow block bearings on each side of the subfloor. Sorry the pictures are bad.

Craig
Title: Re: Help with yoke construction.
Post by: kurt-olsson on October 29, 2017, 06:17:40 AM
I have a picture from the previous owner, serious setup but as you say, require lot of height.

The thing  is that i dont event still with the picture understand how the clevis and spade joint is working. I dont see how it would work when pushing the column forward and backward as the clevis and spade is aligned with the front of the yokes.

Title: Re: Help with yoke construction.
Post by: bernard S on October 29, 2017, 06:20:26 AM
someone on this site   must have chapter 27 for thev73   flight controls that will give you all thevanswers including teentions
Title: Re: Help with yoke construction.
Post by: kurt-olsson on October 29, 2017, 06:31:03 AM
I would like to try with the original linkage because my roomheight is 2,5meters so i think i can do it.
Title: Re: Help with yoke construction.
Post by: bernard S on October 29, 2017, 06:39:29 AM
go with orginal in this case its going to be easier   if anything is actully easy with sim building ..heres why i suggest go orginal   because there are springs on yokes so if one chap pushrs tgr other pulls they pop   leaving onr working   they reset sonits fun   get the bits you miss
Title: Re: Help with yoke construction.
Post by: kurt-olsson on October 29, 2017, 06:51:09 AM
Thanks Bernard, i will try to get some drawing of the yokes so i can see how the actual thing is put together. I think i understand why the clevis and spade joint is rounded, so it can handle elevator movement.
Title: Re: Help with yoke construction.
Post by: Gallie on October 29, 2017, 07:12:06 AM
I also have 2.5 meters and my cockpit floor (original cockpit) sits at 50cm. ive only got 2 cm to spare with the ceiling....

The clevis and spade joint works like a charm... this setup has been working like a charm since the very first 727/737/747's... Just give it a try.

If for some reason you wont be able to use the original linkage parts, you can also try this:
My first linkage project (many years ago) included a aluminum insert into the bottom of the control columns. it supports a shaft through the center connecting both aileron tubes with angled gears. Its very strong, dont have problems with cable tension and so forth. The usage of high quality gears is recommended.
This also meant the total required floor height would be about 15cm..
The insert also made it possible to use a aluminum tube as crosstube, for people who dont have these.
The idea and design of the insert is not my own.

Ive included some pics of this project with measurements of the insert.
Title: Re: Help with yoke construction.
Post by: Gallie on October 29, 2017, 07:18:49 AM
A snippet from the manual.
Title: Re: Help with yoke construction.
Post by: kurt-olsson on October 29, 2017, 10:52:07 AM
I like to simplify stuff and building the "support floor" for the steeringboxes will be as challanging as creating a simple setup like the tube in the column approach.

Your setup looks awesome Gallie!
Title: Re: Help with yoke construction.
Post by: kurt-olsson on October 30, 2017, 12:28:08 PM
Quote from: Caflyt on October 29, 2017, 05:56:00 AM
When I did mine, I had two solid aluminum rods machined to "press" into the original down tubes then the rod was drilled and tapped to accept a 1/2" bolt which has sprockets attached for the connecting chain. I did add a bearing plate to keep the rod from binding from the tension of the chain.
I don't have any pictures of that however.
I had a 1" square tubing frame welded to hold the entire assembly and used 1/2" long bolts at either end which fit into pillow block bearings on each side of the subfloor. Sorry the pictures are bad.

Craig

Hi Craig. How did you press the rods in? Did you donit yourself or did you find a company that could provide this service?
Title: Re: Help with yoke construction.
Post by: Caflyt on October 31, 2017, 02:07:47 PM
Peter,
I actually did it myself.
I slowly tapped it in with a mallet until it hit the riviets  about 1 1/2" in to the down tube. Then I drilled through the existing hole in the tube to insert a bolt to keep it in place. It is a very risky way to do it because there is no way to ensure it is exactly straight, I think I got lucky.
The rod was machined to be VERY tight in the tube.

Craig
Title: Re: Help with yoke construction.
Post by: XOrionFE on October 31, 2017, 05:36:38 PM
Very nice design Craig!
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 01, 2017, 09:20:16 AM
Wow, nice setup.
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 01, 2017, 10:09:32 AM
If i use the oroginal clevis and spade, does anyone know how these parts move when pulling back and forward of the columns?
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 01, 2017, 10:10:24 PM
After some more investigation i think i will try the beveled gears approach. The hardest part will be to find a good spot for the springs for resistance because of my plan is to have the long axel inside the crosstube.
Title: Re: Help with yoke construction.
Post by: XOrionFE on November 02, 2017, 03:53:19 AM
Quote from: kurt-olsson on November 01, 2017, 10:10:24 PM
After some more investigation i think i will try the beveled gears approach. The hardest part will be to find a good spot for the springs for resistance because of my plan is to have the long axel inside the crosstube.

Beveled gears?  Long axel inside crosstube?   Now I think you are going down a rabbit hole.  You should rethink that.   You have two great examples on how to best set this up (mine and Craigs).  That is if you chose not to use your lower boxes.   If I had the lower boxes and the room height I likely would have used them incorporating them into my platform as that is the original design and best design by far.   However, with your room height which is similiar to mine I think it will be tight when you factor in the shell and especially if you were going eventually for projectors.

Scott
Title: Re: Help with yoke construction.
Post by: Caflyt on November 02, 2017, 04:42:02 AM
https://www.dropbox.com/s/imr7zsjhwckda8f/Pitch%20Mechanism.mov?dl=0 (https://www.dropbox.com/s/imr7zsjhwckda8f/Pitch%20Mechanism.mov?dl=0)

By the way, this video shows my "pitch" mechanism also.

Craig
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 02, 2017, 12:41:38 PM
Quote from: XOrionFE on November 02, 2017, 03:53:19 AM
Quote from: kurt-olsson on November 01, 2017, 10:10:24 PM
After some more investigation i think i will try the beveled gears approach. The hardest part will be to find a good spot for the springs for resistance because of my plan is to have the long axel inside the crosstube.

Beveled gears?  Long axel inside crosstube?   Now I think you are going down a rabbit hole.  You should rethink that.   You have two great examples on how to best set this up (mine and Craigs).  That is if you chose not to use your lower boxes.   If I had the lower boxes and the room height I likely would have used them incorporating them into my platform as that is the original design and best design by far.   However, with your room height which is similiar to mine I think it will be tight when you factor in the shell and especially if you were going eventually for projectors.

Scott

Your right, that seems to be very complicated. There must be a reason for 99% of the conversions have the same setup as yours.
I have decided to go with a tube inside the columns and wires between them to connect the movement.

My first Profe-of-concept will not have any bearings, just the rods and the wires.
I have seen another conversion that have this.

But my first problem, if you look at the pictures below, how on earth can i remove the screw thats holding the clever?
i removed the screw on the one side but when screwing the other one the rod just rotates. What tool do i need to hold the rod while loosing the other side. And can this even be done, feels like the rod is designed in some special way. Shoudl i just try to cut it with a saw?

See pictures below...
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 02, 2017, 12:42:46 PM
i will copy this solution.
https://www.youtube.com/watch?v=s29E1CN_k6U (https://www.youtube.com/watch?v=s29E1CN_k6U)
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 02, 2017, 12:46:26 PM
The problem...
Title: Re: Help with yoke construction.
Post by: Caflyt on November 02, 2017, 01:29:57 PM
I don't recall having any problems removing that piece. It was a couple of years ago though.
Have you tried tapping it out with a punch and a hammer?

Craig
Title: Re: Help with yoke construction.
Post by: mickc on November 02, 2017, 02:04:02 PM
Quote from: kurt-olsson on November 02, 2017, 12:42:46 PM
i will copy this solution.
https://www.youtube.com/watch?v=s29E1CN_k6U (https://www.youtube.com/watch?v=s29E1CN_k6U)

In my opinion., you should find a better design to copy.   If you want to make it realistic, that is.
That design only has about 50-60 degrees of movement each way with the for the ailerons, where the real thing has 105 degrees each way.

Another issue would be the way the cables are terminated, that would allow a lot of play between the 2 yokes,

Again, this is just my opinion, there are many different ways to do this.

Also Craig is quite correct, that bolt should just tap out with a punch.  It will be a friction fit into the bearings which is why its just turns.
Title: Re: Help with yoke construction.
Post by: XOrionFE on November 02, 2017, 03:56:45 PM
I just punched mine out as the others have mentioned.

Scott
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 02, 2017, 09:50:38 PM
Thanks all. I will focus also on Scotts design, looks pro and seems to work awesome in his videos.

Scott: Do you have to adjust anything after a couple of years? Like cable tension etc, or is your setup as it was in the videos still?
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 02, 2017, 09:53:24 PM
removed, saw the answer in previous post.
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 02, 2017, 09:54:26 PM
Would also be great to know the diameter of your tubes...
Title: Re: Help with yoke construction.
Post by: bernard S on November 04, 2017, 04:52:25 PM
why an earth are you going down the rabbit hole?.. heck you have the orginal parts . use them save you so much grief   unless you enjoy grief ... get chapter 27 as i said    and your done ...theres the water bowl  for your horse lol
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 04, 2017, 09:31:36 PM
Quote from: bernard S on November 04, 2017, 04:52:25 PM
why an earth are you going down the rabbit hole?.. heck you have the orginal parts . use them save you so much grief   unless you enjoy grief ... get chapter 27 as i said    and your done ...theres the water bowl  for your horse lol

The original setup requires too much height. About 50-60cm, too much for my room. I took the boxes apeart last night, will use the wheels and bearings. Hopefully this setup will be easy. (Almost as easy as the Original setup)
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 04, 2017, 09:33:09 PM
Will use following parts...
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 22, 2017, 11:19:48 AM
Bingo!

Didnt feel right to not use the OEM stuff so i thought about a solution and came up with this!

A smallex box than the original but i can still use the Clevis and Spade joint!
So no rod pressing and custom stuff! This saves me time and money and so cool to have the original stuff. Even the cable is from the real aircraft!

So happy i found this solution. ( even though Bernard kind of told me) but hey, with my miniture stand i pass under 30cm of height!
Title: Re: Help with yoke construction.
Post by: archen on November 22, 2017, 11:43:17 AM
Quote from: kurt-olsson on November 22, 2017, 11:19:48 AM
Bingo!

Didnt feel right to not use the OEM stuff so i thought about a solution and came up with this!

A smallex box than the original but i can still use the Clevis and Spade joint!
So no rod pressing and custom stuff! This saves me time and money and so cool to have the original stuff. Even the cable is from the real aircraft!

So happy i found this solution. ( even though Bernard kind of told me) but hey, with my miniture stand i pass under 30cm of height!
Noticed the "Rusta" cardboard, you from Sweden?

Skickat från min SM-G955F via Tapatalk

Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 22, 2017, 12:12:40 PM
Quote from: archen on November 22, 2017, 11:43:17 AM
Noticed the "Rusta" cardboard, you from Sweden?

Skickat från min SM-G955F via Tapatalk

Jajemen, från GöööteBörg! :)
Gillar dina konstruktioner skarpt, ska nog slå till på dina startswitches sen när jag har det mesta uppe o snurrar.
Title: Help with yoke construction.
Post by: archen on November 23, 2017, 02:10:02 AM
Cool :-) Det finns ett par till 737 byggare i Göteborg



Skickat från min SM-G955F via Tapatalk

Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 23, 2017, 02:38:12 AM
kanske borde ha en byggareträff snart i sverige o samla denna fanatiska trupp. :) Hade varit skoj.
Title: Re: Help with yoke construction.
Post by: bernard S on November 23, 2017, 06:48:49 AM
now you on rightbroad to hell using oem.parts    once the fitment is how you like .. here is of that wood its the devils work   make it out of metal   why because these items you use most ..so no distortion     .. this one of the few items need be strong and correct .why because later on down line you will add control loading by bff ..yiu know you will lol   
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 23, 2017, 09:10:36 AM
Hahah Maybe i will add control loading, but not in the near future! Haha.
I will create a "prototype" in wood and once i know all the measurements etc i will convert it to some steelframe.

Title: Re: Help with yoke construction.
Post by: Flying_Fox on November 23, 2017, 12:40:48 PM
My design fits into 20 cm floor level  :angel:

http://elephantair737.blogspot.ca/p/control-columns.html (http://elephantair737.blogspot.ca/p/control-columns.html)

:2cw:

Nick
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 23, 2017, 09:11:49 PM
Quote from: Flying_Fox on November 23, 2017, 12:40:48 PM
My design fits into 20 cm floor level  :angel:

http://elephantair737.blogspot.ca/p/control-columns.html (http://elephantair737.blogspot.ca/p/control-columns.html)

:2cw:

Nick

Yeah, thats one nice thing when not using the OEM steeringbox and crosstube. You can go low! (Hip hop song someone?)
Title: Re: Help with yoke construction.
Post by: bernard S on November 24, 2017, 05:03:55 AM
kurt may i make a suggestion with regards to yiyr buikd and where you are at now...  what you are doing is super cool period..oem parts for somethings are the only way to go... what you are doing noe is emuati g a simulator rather than simulating the aircraft  there is a huge difference between the two ...

my suggestion is since you are doing up down and left right with your control uprights... and you have it all open i think.the best bang for yiyr buck is to add control loading now.. just on a single control surface   ... the pretty stuff can come later .. it may not make sence to you now   but with cl.in place yiur "sim" is noe a sim
and it will not fly like a train    .. if you ever do one thing I tell yiu.. this is it ..lol
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 24, 2017, 08:40:08 AM
I will make the box easy to access. I feel that i dont have any knowledge in control loading right now, so i need to do some investigation first. I dont even know what parts to get. :)
Title: Re: Help with yoke construction.
Post by: bernard S on November 24, 2017, 09:56:34 AM
a linkage   bff software and a motor
Title: Re: Help with yoke construction.
Post by: kurt-olsson on November 26, 2017, 11:40:41 AM
Can anyone help me confirm that the spade and clevis joint is properly setup. When the film begins i have the yoke centered. In the drawings and some samples i have seen that the spade and joint is turned 90 degrees.
Just would be glad to get some input of anyone who has used the same setup.

https://youtu.be/YvRzmMrxQUo