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by rye-neat 713 days ago
I'm building a streetable rock crawler out of a 78 F150 with a custom radius-arm suspension in the front. I needed to measure the deflection of the drag-link & track-bar as the front axle cycled up and down while changing a few variables: mounting locations, drag-link/track-bar angles, and drag-link/track-bar lengths. I used plain Javascript to display a graph, lines representing the drag-link and track-bar, enabled them to be clicked+dragged along with their mounting points and sizes.

With this visualization I was able to determine the best way to package this on the vehicle with the minimal amount of deflection to avoid bump-steer and death-wobble.

I suppose it would be useful to other people building radius-arm/link-suspensions that incorporate a track-bar but I haven't got around to hosting it any where.

2 comments

That is really cool. I haven't built a rig like you, but I have it on my bucket list to build a fully dressed rock crawler out of a Mitsubishi Montero 2dr (also sold as a Dodge Raider in the states). It'll be leaf sprung to start, but using your method of going 4 link would be preferable to the "build and pray" method that most people seem to take.
I'm a mechanical engineer, so I'm always intrigued by visual calculations like this that exist outside the standard CAD/excel paradigm. Is there any particular reason you went this route for this application? Do you use a pre-built framework to enable rapid creation and iteration of the setup?
I went this route because I'm a software engineer that mostly works with Javascript and needed it fast. No framework but bounced a lot of the problems off of Chat GPT to help me figure out how to get it done. I also figured it would be more useful than a CAD model to non-technical folks if I made it available online.