A few months ago I bought a second hand sim racing wheel, so I decided to practice drift, but there is not much joy just pressing a button, so checking how they work I tried to build my own.

Actually the operation of these devices is very simple, it is only necessary for the lever to press a button, other more complex models use a potentiometer to achieve greater realism, of course I decided to try the second option.
With this in mind I remembered that I still had a cheap steering wheel from my children, it was broken so I opened it and I found some interesting pieces for this project.

Step 1: The Scrap

My interesting discovery consisted of the USB controller of the entire device and especially the white part of the second image, this was the steering wheel core, a kind of cylinder that contained a fairly strong spring that gave resistance to rotation and a potentiometer to detect the movement.

My plan was to connect the handbrake arm to the axis of the cylinder, achieving the resistance with the spring and the sensitivity with the movement of the potentiometer in one direction (the potentiometer was factory calibrated at half travel to have movement at the left or right)

Step 2: The Idea

Well, the idea was to build a small structure that would hold everything in place.

First a T-shaped base plate with a slanted end to hold the potentiometer frame, then an arch supporting a bearing through which a shaft would connect the arm to the cylinder, and lastly two plates that would screw into the arm to hold it.

(This design is intended to be attached to a complete structure for sim racing in the future)

Step 3: The Arm

This part is very simple, they are some bars joined to get more thickness. At one end it has the necessary holes to join it to the other plates. It is about 40cm long.

Step 4: Join Plate

I built two plates with this shape to join the arm with the bearing axis, in the larger hole one end of the axis will be welded.

Step 5: Base Plate

The T-shape is intended so that it can be attached with screws to a larger structure. It would be easier to use a square or rectangular base but I only had that type of plate. The arc will depend on the bearing.

Step 6: Axis of Rotation

In this part it was necessary to make a modification to be able to correctly transmit force and movement. On one end of the shaft I welded a circular plate with four holes. Inside these holes will fit four screws that I inserted into the potentiometer box.

Step 7: Pull Resistance

When doing some tests only with the resistance provided by the potentiometer spring, I realized that it lacked a bit of hardness. For this reason I added one more spring joining the lower end of the arm and a part of the base plate. With this extra I liked the sensitivity much more.

As an extra, the screw that holds the spring is a little longer so that it also serves as a stop for the arm in its zero position.

Step 8: Electronics

Nothing new in the electronics, I used the board and the cables just like I got them from that old steering wheel.

Step 9: Additional Features

Here just a few details to improve the aesthetics of the handbrake, I made a metal plate to cover the space where the potentiometer was seen; I glued a kind of washer that I found right on the end of the axle to hide the welding and I also placed a bicycle handle on the end of the arm for greater comfort.