Three Wheel Cars: Our 3VG DIY Car Leans Toward the Future

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Variable Geometry: The 3VG Feature

And, you may well ask, what's MOM's prototype like to drive? Well, in a word, it's exciting. Corners and curves put this machine in its element ... and there's nothing quite like sweeping around a hairpin bendbanked over and feeling the tires grabbing the pavement for all they're worth-to Out some fun into a driving day. What's more, the vehicle's stable footing and wraparound chassis take the risk out of this carnival ride, and-should the driver want a more sedate cruise-he or she can even "tone down" (or actually eliminate) the lean simply by turning a control knob!

Although we tried a number of different mechanisms in our efforts to find a system to induce camber in the car (because it has more than two wheels, it can't lean natural ly like a motorcycle), only a handful proved successful. The "inclination" is at present controlled through a combination of mechanical, hydraulic, and electronic components ... all of which are available as "off the shelf" equipment, and some of which are so basic that they're commonly used in many toys and pocket calculators.

Of course, since the system must acknowledge varying degrees of lean (it would never do to have it be capable of offering only "on" and "off"), three separate inputs are constantly fed into the car's computer control to alter the steering/ leaning geometry (hence the triple-variable geometry 3VG—label). The first factor is the radius of the curve being negotiated (seen as a function of the position of the steering wheel), the second is the speed of the vehicle (the faster it's traveling, the more radically it leans into a turn of a given radius), and the third is the driver's preferred setting of the system, which we mentioned earlier. The bottom line is that the cambering mechanism transfers the vehicle's center of gravity-through chassis/body inclination to the inside of a turn ... thus not only shifting weight to where it'll do the most good, but also enhancing the driver's and passenger's comfort (and feeling of exhilaration), because the seats bank with the car and thus minimize the sideways thrust forces experienced by its occupants.

In plain language, this means that we've achieved a workable balance of excitement, comfort, and safety ... in a package that, if it were manufactured today, probably wouldn't cost more than a touring motorcycle. Of course, this one's just a prototype ... but who can say just what the future might hold for it? Meanwhile, you can look forward to the next issue of MOTHER ... in which we'll present more details, including some nitty-gritty information on how we actually built our "dream car."

What's Next?

As we've said in the accompanying article, our experimental vehicle is a prototype: a one-of-a-kind car that was built to test a great number of calculations and one "impossible" concept. And it does function impressively... but only because we developed—and scrapped-at least six previous designs before we came up with one that could prove itself under the various conditions that most drivers are likely to encounter. Some of our earlier efforts functioned well but rode harshly . . . others required excessive steering effort... and some just plain didn't work.

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