Buz DiVosta's Roadstar...food for thought

Joe McGlynn — Sun, 30 Nov 2008 07:03:00 GMT

First, it's Roadstar, not roadster. The star reference is to the Caddy Northstar mid engine that powers this beast.

This car was built by Boyd Coddington's shop for Buz Divosta and won the AMBR award at the Oakland Roadster show. I saw this car in person that year and it was a knockout. I've been curious about the front suspension for a while, and a friend pulled a few pictures out of his archive to get a better idea of the details.

Here is the effect, it looks somewhat like a swoopy dropped axle. There are one or two things missing. First, no (visible) spring, second it doesn't have any locater bars like a radius rod. Conventional wisdom would call for some sort of locator bars, but then Boyd didn't accomplish what he did by being conventional.

If we look at a shot of the car with the front end opened up you can see how the suspension worked. The suspension arm hooks up to reduce camber change and then there is a very large, beefy pivot. This is all there is for lateral support.

Logic tells me that this is weak geometrically, but it looks bitchin.

I can't quite make out the steering system, but it would need to have the tie rod inner pivot points near the inner suspension pivots to avoid bump steer. It looks like it may be a center steer setup.

Here is what I find interesting about this from a conceptual standpoint. This system provides the potential for a very smooth look, and gets all the suspension out of the wind. This one is obviously all carved out of aluminum, which makes it a poor fit aesthetically for a traditionally-styled car. But this could also be developed as a steel fabrication.

I can imagine a lakes modified with something like this, but built in a style appropriate to the period. As a starting point I worked up a quick CAD rendering of how a lower arm could be fabricated from 2" OD 1/4" wall tube. Another thing I like about this is that it is something I can make rather than something I can buy.

Tuck Shrinking

Joe McGlynn — Wed, 26 Nov 2008 07:52:07 GMT

This video was shot at a metalshapers.org meet several years ago. It shows Tom Lipton using a helve hammer to flatten out tucks and shrink the edge of a panel. The tucks are formed by hand using a "tucking tool", which looks something like an industrial tuning fork. The two tines straddle the panel and it's twisted left and right to put a raised ridge at the edge of the part.

Using a hammer (and a plastic or wood mallet works just as well as the helve hammer" yo flatten the tucks out. Start at the back of the tuck, then hit either side of the tuck to keep it "locked in", then at the innermost point again. It takes a bit of practice to know how much of a tuck you can take, how to get the most shrink from each tuck and so forth. Needless to say, the metal should not be allowed to fold back over onto itself.

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Buz DiVosta's Roadstar...food for thought

Tuck Shrinking