Pedal Problems... What's really going on here?

*** Warning - Technical Info Follows ***

It's Magic!!! No, I'm joking of course... It's not magic. Although, in one forum someone stated they "think it's voodoo magic."* Well, as much as it pains me to say it, I'm not a magician or voodoo practitioner. What I am is someone that doesn't often take no for an answer.

The root of the problem:

Let me start by saying "stop taking your pedals apart!" Doing so is a waste of your time and unnecessarily risks breaking the brittle plastic inside which holds the potentiometers in place as well as the brittle solder joints. There may be a time when you have to take them apart, but it should not be the first step you take. "But they work better after I take them apart!" They sure do, for a few hours, sometimes days... I will get to the why later on.

The root of the problem is very simple, "dirty" potentiometers or "pots." While there are many different types of potentiometers, almost all operate on the same principle: A wiper moves along a resistive element and the resistance varies as this wiper moves along the element. The simple version is that a piece of metal is physically rubbing against another type of metal. In an almost unavoidable fashion, this process eventually begins to create bits of rubbed off metal dust that collects on the wiper as well as the surface of the resistive element. This "dust" is the cause of all our problems. This phenomenon is not unique to the pots used in these pedals... Have you ever turned the volume knob on a stereo and heard that crackling/hissing sound while you move it, especially on an old stereo? That is caused by the same exact thing plaguing these pedals. You are hearing what the wheel is seeing coming from the pedals... To illustrate the point more directly, I have included a plot showing what the signal looks like coming out of my own pedals, without the filter attached.

This graph shows me pressing the accelerator pedal all the way down in a little under 1 second:

Some of those fluctuations are as much as .75 volts! There are other issues here as well, but I'll save you the detail... The short of it is that the wheel really doesn't like this.

Now, I have read many many posts by people stating their pedals work great for a little while after taking them apart and reassembling them. Mine did too... The reason for this is that in order to take the pedals completely apart, you must rotate the pots well out of their normal range. In doing so, you move the wiper across clean portions of the pot, which cleans the wiper a little bit.

Zip ties, epoxy, fairy dust, prayers, none of them will fix the problem. The pots aren't loose, at least not enough to cause this problem. They are dirty.

The Byproduct:

The Fanatec** wheels, and probably many others, use auto-calibration to set the minimum and maximum pedal positions for each pedal. As you can see, the signal from the pedals when the pots are dirty is pretty horrible. When you combine these two facts you get pedals that don't work correctly or at all. When you see that the gas or brake will not reach it's full potential, this is because the wheel has read a spike from the pedals that is higher than what it normally sees, creating a false maximum. The same can happen with the minimum, creating a situation in which one of the pedals is stuck "on" a little bit. There are also certain conditions that need to be met in order for the wheel to recognize that pedals are connected. This often won't happen properly with dirty pots and is the reason why people repeatedly replug their pedals in and restart the wheel.

The Fix:

Like I've already said, the PF1 Pedal Filter is not magic... It's science baby! :) (but not rocket science)

It does exactly as the name implies, it filters the signal from the pedals, removing all those nasty spikes. It's really that simple and here is the proof -

Here I'm just pressing the gas pedal up and down a bit with the filter connected in-line:

Thanks for reading. I hope this has given you some insight into what's really going on here.

* If you're the person that stated this, let me know if you'd like me to mention your name.
** "Fanatec" is a registered trademark of ® Endor AG. As well, Basherboards is in no way affiliated with Fanatec or ® Endor AG.