Yoke and Column Build Part 1 - Warning...lots of pictures

[XOrionFE]

Well, after a lot of trial and error and thought and thanks to many of the ideas from Ian's yoke build I finally feel like I got my yoke and column project underway.   A picture is worth a thousand words so here goes.  Note that the yoke is real and the hardest part for me was cutting it as you will see but I just could not figure out any other way to do it and still have it work the way I envisioned.  If you are squeemish about doing this then I suggest getting one of Dodiano's yokes from Throttletek instead of a real one.   This design should work fine with his molded yokes from what I can tell.
Also, although not perfectly scale on the column top, this design can allow for a different type top to be molded later if desired.  I am happy with this semi-scale look and after I put the decal for the roll degrees on the top and paint this Boeing Gray I am sure I will never notice while flying.    Note also that there is a gear for driving a pot with a small belt which I have not added yet (Grainger item 2L519 http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=2L519&op=search&Ntt=2L519&N=0&sst=All ).  This will connect to a second pulley and pot further down inside column.  You will also see the control horn that will work the cables and a tension/centering spring. This part also acts as a hard stop for rotation of the yoke at aprox 180 degrees each way.  This whole design by the way has no play and is very strong.  The steel bar is 3/16" x1".  The top threaded rods and nuts are 7/16.  The bottom nuts and bolts holding to the column are 5/16.  Pipe is 3" PVC as is top part.

















































You can see larger sizes on my Flicker site at the following link:

http://www.flickr.com/photos/orionsbelt/sets/72157622388681607/


Next will be lower column parts based on my friend Ron Rollo's design which the upper columns will attach to.   The plan is to run a pully system Between the two to enable them to be synchronized.

Regards,
Scott

[mpl330]

Nice work!

I was cr@pping it cutting one of Roberto's yokes never mind the real thing!
Cheers
Mike

[Boeing Skunk Works]

That's nice work Scott. Like I've said before, there's a 100 ways to do the same thing and they all turn out nearly identical. That's nice engineering.

[Trevor Hale]

Nice work Scott..  I was looking at the pictures from top to bottom, and as I got to the picture of the Ram Horn attached, I almost crapped myself, wondering how the heck you were going to make that look so freeking good. 

Man, you succeeded It looks dynamite!  Nice job, and thanks for posting.  I can't imagine how pleased you must be.

Trev

[XOrionFE]

Thanks guys.  Yes Trevor, I am really pleased with it.   Most of the design credit goes to Ian.   I changed his design slightly to allow mounting to the front and back of the PVC pipe for added stiffness and also increased the diameter rod size.   This then necessitated using a different top fitting instead of the 90 degree elbow so basically sacrificed some looks for the added strength.    Now it feels really good and strong and there is virtually no play in it.   Now hopefully I can marry it properly to my friend Ron's column base setup (which you can see in Shane's Lear 45 cockpit build if you look carefully at his floor pictures inside his shell).

Thanks Ian!!!

[XOrionFE]

Yesterday I finished some more work on the yoke and Columns.   I spent time hooking up a pot for on the captains side along with centering spring.   Here are the detail pictures.   I also finished up the F/o side column top which only requires the centering spring and horn for the cables (last picture).

Bracket for holding the potentiometer...


Welded a stud on for attaching the lower pulley and potentiometer bracket...


Put on an attachment point for centering spring....


Everything put together...works perfect....




This is the copilot side column head.  Only requires cable horn and centering spring


Picking up my second real yoke for F/O later this week from APHS.   Hopefully will have columns
attached and lower part done by end of this weekend and pictures will follow.  I also figured out that I do not need to fully split the pvc top section in half.  I can leave the very top uncut and spread the bottom far enough to drop on over the mechanics then hold with only two screws.   Works like a champ.

Cheers,
Scott

[Trevor Hale]

Awesome Scott.

It will be interesting to see how you manage to get the pot centered and the belt lined up to be able to get the full deflection either way.  Does your pot have enough travel in it to accomplish this?

Trev

[XOrionFE]

Well I did get it centered pretty good but because the pulleys are 1-1 you only get 180 degrees travel out of the pot and I think the full travel of the pot is 350 degrees so obviously I am loosing resolution.   That said, Grainger has those pulleys in smaller sizes that will still fit on the 1/4 inch pot shaft so I can easily purchase a smaller lower pulley and change out quickly if I dont like the resolution.  This would allow me to get more of that full 350 degrees of the pot with only 180 on the yoke.

What I am a little worried about is how well the cables will work going to the full vertical throws of the yokes in each direction since they will rub on the sides of the pot bracket when at full deflection.

We'll see.   :-)  I will be sure to report.  Maybe even make a small video with tops off showing the mechanisms in action.

[XOrionFE]

I decided based on some recommendations from a member at the Hangar45 forum that instead of using a horn method of connecting cables between the two yokes that I should be using pulleys instead.    I needed pulleys to hold very small 1/8" plastic coated cable I plan on using and it had to be just under 2" in diameter.   I also needed them to be relative slender because I can only fit so much on the top of the column in the space I have.    Well after hunting around I couldnt find anything that fit the bill.   Then while at the hardware store in the nuts and bolts aisle a solution sprung into my brain.    I got what I needed and ran home to my acetelene welder and viola....what you see below is what I came up with.   I think this will work perfect.    Thought I would post in case anyone else has run into this need before.   All you need is some washers and a little brazing....









Now I have to figure out how to hold the cable from slipping.   I think one way is to cut a slot on one side of the pulley (notch it out) and then put a large lead fishing shot crimped on the cable that would ride in the notch at the 12 oclock position.   

Regards,
Scott

[Trevor Hale]

Scott,

I have just the thing to suggest.  In the Electrical section of the hardware store you will find these..  Marrettes (With the wire nut) and the cap.



Discard the plastic cap, and weld/braise the other peice to the top of your "Pulley"

This way once you have the cable ran (Be sure to use one piece looped through all pulley's) and secure them on the top of each yoke.

The screw will allow you to adjust the position of each yoke as you see fit.

Trev

[XOrionFE]

Great idea Trevor!  I like the idea of being able to adjust and this would work perfectly.I will still have to notch it in because there will be very little room between the top of the pulley and my bracket but the set screw will be wonderfull to have.   Nice....

Back to the hardware store....

[Trevor Hale]

Yes, it worked great on my setup, and I assure you there was no slip.  and I notched my pulley's. but what I used for pulley's was these.. and I pulled the pulley's out of them..



Anyway, the string you have will stretch and change with temperature and humidity. make sure you get thin cable (For hanging pictures) and run one constant cable around all your pulley's and join it in the middle under the floor.

Good luck,

Trev