VPP Steering Wheel rebuild

Ones there was a brave hero - his name was VPP Steering Wheel. He partook in many glorious fights at Watkins Glen, Daytona, Silverstone and Sebring. The years gone by and our hero became old and wane.

So Nima took a cardbox and send me our hero. Following some pics of...the thing I found inside the cardbox:







...erm.... I grabbed some tools, duster and cleaner and took the wheel apart. All wires (except three) inside the steering shaft were broken. You can see the nipped black tube in center. On the left is the broken adapter for motors and cogs. The motors are lowcost 12V DC motors - this type of motors is also used in RC cars.

I dig around and put some goodies together. Alloy pulleys, belts, ball bearings, motors (24V robotics motors), incremental greycode encoder, FFB controller (ATMega48), LCD, some knobs, DC/DC step down converter, power supply (24V/25Amps), Copley motor controllers, h-bridges and some goods to tinker all that stuff together.



To attach the pulley to the steering shaft, I had to drill a 28mm hole. Also tapped two M5 threads to keep the pulley where it belongs to.





Next pic is to compare old and new motor.



Next step was to test arrange all that mechanical stuff to check if the belts having the right size. I think they fit just perfect. The encoder is already on its place (upper motor).







And now I'm hungry, tired and drunken. No more tinkering for Jay today.

More to come...

Looks very promising! One of those motors would be enough, two of them will have more power than anyone can handle.
The belt drive IMO is the best choice, very smooth and responsive if the tension is right.
:clap: :

Interesting.... I have five of these wheels on the shelf.

Very nice work so far Jakob

hi jay,
i love what i see on your pictures very mutch.its very nice work and with the new power your new interface and x-sim we can make a very nice wheel.
thank you very mutch for your work.

The Wheel needs two motors and two h-bridges to drive it with four X-Sim axis. They are powerful but there is no need to drive them with full torque. I use them because each of them has four ball bearings inside and they are very durable. But I could also use a pair of these:


:brows:




@CXCSimulations: You bought five of these wheels? Sorry, but they aren't nearly worth their money. The wires aren't soldered together. They just twisted them and fixed them with shrinking tubes. And they didn't use high flex wires inside the steering shaft. I could pull out almost all wires from the wheel. They were broken inside the shaft. H-brides are home made and the parts may be worth 10€. Same for the joystick controller: Two microcontrollers and some electric dings and dents. The motors are noname RC motors from china without bearings and they cost around 2€.

The case, the wheel, shaft, shaft bearing and the red knob thing. These things are good quality parts and barly worth 500€.

So you will output only 2 X-Sim axis to each motor? Please correct me if I'm wrong. Driving 2 motors with 2 different drive signals you will run into all sorts of problems, the very first one is the belt stretching after a short time.

A pair of those huge motors would be literary a safety hazard. They could produce so much torque at the wheel that they could pull muscles without hesitation, even break an adult's arm. Of course you could run them at half power, but then what is the point of having them?

Go on! :thbup:

The idea is, to let the motors run a bit asynchronous. One motor runs permanently with lower torque (primary motor) than the other (secondary/supporting motor). The primary motor will do the stiffening job and the wheel movements when driving banks, hills and corners. This motor could be assigned to car velocity and some of the car movements in X-Y-Z.
Secondary motor is only for vibration and all the hits you'll get when rocking curbs or racing the track furniture like trees, walls and other cars. Axis like RPM for wheel vibration at lower RPM, car movment in X-Y-Z but with other gain. This motor will also be controlled in its movement be the FFB controller. Not only by X-Sim. ATM I don't know how intense this influence will be.

Primary and secondary motors will need a very fine balancing. Same for the X-Sim axis. Otherwise the belts, bearings and motors will wear out too fast.

I really don't know if it will work out. But its worth a try, I think. I spend many, many nights to build the FFB controller and the software/code for it. Too late to reject this project.

That is a very interesting solution. IMO your mechanical construction is not suited for it. If you want to run the motors asynchronous, they need to be connected to the shaft independently. Now I don't know how you can do that.

There is no way to balance their motion. Each of them will do their own movement and torque their own way. These force vectors will be often opposing, putting extra stress on your parts, stretching the belt. Other electrical issues may arise, overheating, over current and over voltage just to name a few. Wouldn't it be easier to mix the effects into one synchronous motor output?

There is no need to reject the project. You can always write new code, and you will. Prepare for many many more hours and nights playing with the firmware. :yes:
An oscilloscope will be your best friend testing the electrical characteristics.

Driving the wheel with two belts sounds interesting. I have some narrower belts and the wheel pulley is very wide. I'll give it a try, thanks.

So true. I build an AVR based two channel oscilloscope only for this purpose - testing the h-bridge outputs and all the other signals. It can measure only up to 250kHz so its not really an oscilloskope, but it should be enough for checking the PWM. The FFB controller will output max 25kHz.

Using two belts isn't going to help, it will just complicate the mechanics. As long as the motors are tied together at the wheel shaft, they will have an effect on each other.

I guess the only way to find out is to do it and see what happens.

250kHz should be enough for what you need, but it won't be that accurate. If you can find an older Tektronix or similar analog scope I would recommend to get one. They are large and heavy but the accuracy beats any of the digital scopes.

Tektronix oscilloscopes are indeed beasts. I use them (four channel 500MHz) at work. But I don't have 10.000$ :shipwrecked:

But 50 or 100MHz should do the trick, too.

On topic: I compared the torque/rpm of my motors to the china motors from the VPP. There's no need of a multi belt drive like here:



The china motors do need such an transmission to work at the optimum torque/rpm. My motors are slower, they don't need to run very fast to perform good torque. I guess, I'll run some tests with a direct drive: two motors, three pulleys (big one on wheel shaft and two small at the motors) and a single belt.

You are right. But two instead of one single belt should prevent a fast belt wear. The torque will be spilt.

Very nice work.
I think you should use just one motor, and mix the efects in controller board.

here is my wheel, some progress, I did some speed testing, I think it´s okey.
24V, less than 5 amp, I´ll use an L298 chip.

http://www.youtube.com/watch?v=p99Kr9soEP0

regards

I have 7 of these VPP wheels for sale if anyone is interested. I will sell them cheap

Great Job, i'm trying to upgrade my cheap steering wheel because it doesn't have FFB and only spin 270º or 300º. then i have to change algorit.. potenciomenter for a linear, some gears and FFB system.
thanks for your insparation.