How to build a yoke ?

On this page I will show you in detail how I build my yoke. Click on the pictures for a detailed picture.

This is the real B777 yoke

I bought this on Ebay. This is a good site to look for used aviation stuff and very cheap. This yoke is from an aero commander. The good thing of this yoke is that it contains 2 switches, the bad thing that it needs some repair.

I removed the plastic coverage, sanded and cleaned it and put a alu plate for the openening. At the rear side you see a 5 cm alu tube that fitted exactly. That tube is needed to connect the yoke with the colum.

Four pieces of plywood wil be connected to form the colum.

I put a part of a garden hose with a connector around the alu tube after it enters the colum. It keeps the 2 parts connected very good and it is a very simple construction. You also see the horizontal bar. This will block the aileron movement after about 45 degrees in both directions.

In the alu tube is a wooden rod with a hole in the end to accept the aileronpot. The pot is on a alubar connected to the yoke. It is completely on the left. The body of the pot is in a opening I made in the wooden backside of the yoke to build it more compact. The opening will be covered with a metal cap.

First I experimented with gassprings. The disadvantage was when you would get your hands of the yoke it would stay wherever it was when you let it loose. With normal springs I feel resistance and it turns back to the middle position when loosened. Ofcourse in real the position of the yoke is always where the elevator is. In fact you even see the yoke move when the aircraft starts climbing via input to the FMC or MCP.

With gassprings the yoke would still be in takeof position at decision height where I would switch of the AP. Now it is in the centered position, not real but more real then gassprings. Building an autoyoke is unfortunately beyond my capabilities. On this picture you see the connection between the yoke and the elevator pot. It is the same technique as used in the throttle.

I was not satisfied with the first color. Now I use E4.15.25 (Flexa Ambiance).

Next part will be the FMC.

The beginning of the dual linked yoke. I used my CNC machine to make 3 layers (12-10-12mm). In the middle layer there is room for the wires. The wires will leave the yoke through the little hole below the axis.

For the aileron axis, I use a 8 mm iron rod. On both sides screwthread is made.

The axis is fitted tight to the yoke. I made 5 3mm thick plexi rings with an outer diameter of 75 mm. That is enough to keep it at place in the pvc pipe, no additional fastening is necessary.

The gear is fitted tight with 2 nuts to the axis and the yoke. The plexi ring can turn freely. When everything is in place, the plexi rings will not be able to turn because they are fitted in the pvc tube , and the yoke will turn freely.

The remaining part between the gear and the clear plexi is filled with small white plexi spacers (glued to eachother and to the clear plexi). If you fill it up nicely, there is no slack, and the yoke can turn freely.

If you take a good look at the clear plexi, you wil notice a semicircular opening.

The opening under the yoke axis, described earlier, will contain a hollow aluminium 8mm rod where the wires go through. The opening in the clear plexi will guide and block that aluminium rod. In that way the turning of the aileron is only 60 degrees left and 60 degrees right.

CAD drawing of the aileron mechanism. Red is the PVC piece with the round plexi rings. The blue axis has only screwthread on its end (dotted line). So the yoke itself is clamped between 2 nuts, and the gear the same. Between the 2 inner nuts is no screwthread, and so the complete mechanism can rotate freely.

Front side of layer 1 and 2 of the FO yoke (below) and layer 3 (above).

The picture to the right shows the same layers, but now from the backside.

To get the circular shape, I first made lines 9 mm from the edges (4), remove everything under an angle of 45 degrees with a file, then make again lines 4 mm from every edge (8) and remove that under an 22,5 angle. At last use a fine file and sanding paper to get it perfectly round.

Sanded, painted and switches are in place.

You can see the wires comming out of the aluminium tube. That tube will block the movemen of the aileron because it will slide in the smiley-like opening in the plexi art of the yoke column (see picture in the row above)

A horizontal bar (40x20mm) will be the connection between te left and right yoke column. I connected 30 cm vertical aluminium to the horizontal one. The PVC tube is then connected to the vertical one.

The horizontal axis around which everything will turn is in place here. Also the pulleys for the cabe of teh ailerons are in place.

Connected!!

I redid this part and included 2 ball bearings. These are in the entrance and exit of the plexi part (see cad drawing for details). There was a little slack in the aileronaxis. When tension on the gear was applied, the yoke tilted a few degrees and that induced friction at the yoke's 12 o'clock position.

In the front is the dc motor (conrad 227552-89, driving the elevator trim motor. When it turns, the springs will move for- or afterwards, and change the equilibrium of the springs. I use 4 springs of 80N.

Do not forget to have some microswitches at both ends to stop the motor.

This is a special relais for dc motors. (conrad number 505013 - 89). In fact it contains a H bridge. In this way I am able to operate the dc motor from a (on)-of (on) toggleswitch (the trimswitches in both yokes).

One part of the floor is ready. The forward part with the pedals and the afterward part with the seats will be next.

An original mapholder installed.