Friday, October 31, 2008

First test!

They work!

I plugged the pedals in last night and went through the calibration process. After just one small glitch I was in the Skippy and driving around Infineon. After only a few laps I was within one second of my personal best there.

Then suddenly the brakes "failed!" I went into the upper hairpin (turn 7) at Infineon and pressed the brake and nothing happened. I drove off the end of the dragstrip into the grass and then fell off the end of the iRacing "world."

A quick look under the table revealed that the crossbeam on the computer table had snagged the brake spring and prevented the pressure from the pedal from getting to the brake actuator. The table slides fore and aft, and as I drive, I tend to pull it toward me. I'd raised this crossbeam a few weeks ago, but clearly I hadn't raised it enough.

Other than that, the pedals felt pretty good, but it was clear that I needed to make some adjustments to the pedal angles and heights. For one thing, the brake pedal felt kind of soft, and I was locking up the Skippy's brakes too easily.

Since it was well after 2 AM I decided to knock off and have another go in the morning.

In the morning after some more testing I decided that I needed to raise the front of the pedal unit. I didn't like the angle that the throttle and clutch pedals were at when they were fully depressed, particularly the throttle. When I pressed it all the way down, my foot bent back at an angle and I was only pressing it with my toes and the ball of my foot.

There wasn't enough adjustment left on the pedal pushrods to get the pedals where I wanted, so I unplugged it (just a single USB connection!) and took it back to my bedroom "workshop." There was one adjusting hole in the aluminum straps, and I tried that, but it didn't raise the front enough to get the throttle at the angle I wanted.

I wound up drilling a new hole in each leg, and also doing some adjustment of the pushrods to get all of them into the same range so I could fine tune the angles once I got the height into the ball park.

I also found I had to make some adjustments to the pot actuators. The new pedal positions caused some interferance with the little plastic arms on the pots coming in contact with the large washers that serve as spring perches on the pushrods for the throttle and clutch. A little filing on one of the plastic arms and shortening the little pushrod on the other took care of the problems.

All this was minor stuff, the type of thing I expected to have to do, and fun besides. Less fun was raising the crossmember on the table, but it didn't take long to do this.

All the pedal angle tweaking required recalibration of the throttle and clutch, and while I was doing that I realized that I'd only calibrated the brake to use about 30% of the full range of the load cell. No wonder the brake pedal felt so soft! A quick recalibration got me up to 50%. I didn't want to go too high for fear of overstressing the load cell, but later Todd told me the load cell is good for up to 150% of its rated load, and that I can safely calibrate for 90% of its range.

Anyway, soon I was back in the cockpit of the Skippy. Now the throttle pedal angle was good, but the angle of the clutch and brake were too high. I was snagging my foot on the bottom of the clutch pedal when I tried to use it.

A few minutes with a couple of 7/16" wrenches and I'd cut back on the angle, and raised the brake and clutch pedals relative to their shafts, while lowering the throttle pedal relative to its shaft. All that adjustability we (and Todd) had designed in was paying off!

Now the angles and heights were just about perfect, but the throttle and brake were too far to the right. A few minutes with an allen wrench and I'd slid all the pedals to the left so their lateral positions were pretty much optimal too. Bravo to Todd for his design, and to Amos for his careful machining. It was very satisfying to be able to make all these adjustments so smoothly and easily.

Back in the car. This thing rocks! Within a handful of laps I was under my previous personal best. A few more laps and I'd lowered it by half a tenth, with several more laps within a tenth of the best.

This may not seem like much of an improvement, but I have not been driving much in recent weeks, so I'm rusty. Plus, there are a lot of variables. I'm using the new iRacing build, some different FF and steering linearity settings, and a different setup for the Skippy.

What is clearly different is how much more consistent I was. It's very rare that I am this consistently close to my personal best.

I still have more fine tuning to do, and I also think it will take me a little time to fully adapt to the pedals. But already I think they are better than my modified G25 pedals, which in turn were better than the stock G25 pedals.

So far I feel very gratified with the results of the project, and I'm looking foward to putting some more miles on the pedals. I'll report back soon.

Thank you Amos! I loved working with you on this project, and I really appreciate all the hard work you put into it. I'm really looking forward to building your set.

And thank you Todd! Thanks for all your help, and thanks for creating such a terrific concept and such a well executed design.

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