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Old 04-09-2014, 02:28 PM
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Graham08 Graham08 is offline
Master Fabricator
Join Date: May 2006
Location: Denver, NC
Posts: 1,737
Originally Posted by TheBandit View Post

I haven't had much time to think through this, but what is the effect of having the Watts pivot mounted off center? Are the axle pivots also going to be off center with equal length connecting rods?
Thanks! It's only badass if it actually works on the track.

The offset Watt's linkage mounting not a big deal. For the most part, the vertical loads from the links being non-level during travel cancel each other out. It's not like a Panhard rod where you start to get significant jacking forces when it's not level. This is the biggest effect that an asymmetric mounting would cause: asymmetric wheel loads due to the jacking force being applied somewhere other than the center of the axle. This can be a tuning tool with a Panhard rod on ovals, which makes the Watt's linkage a compromise because you lose the ability to manipulate the jacking force. The other side of the coin is because the Watt's linkage provides linear motion over a large range, it doesn't bind the torque tube, which should be better for grip.

The reason for it being offset in the first place is because sprint cars use an open tube axle. The axle itself is exposed and must be supported on the ends with bearing carriers ("birdcages"). This limits possible mounting locations on the rear end to either the quick change center section or the birdcages. The links will be equal length, with the lower one mounted to the left side of the center section (it will go underneath to get to the left side), and the upper link mounted to the right birdcage.

I have a fair amount of work ahead of me to get to that point. I have to make the birdcages, the mounting bracket on the center section, and the links themselves.

As they say, when one plans to think outside the box, one should also plan on being lonely!
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