DIY Car part 2 - my progress so far

Although I haven't mentioned it since my first post, I have actually been doing a fair amount of work on the Locost, a sports car which I'm building. Although it's still very far from being finished it is now starting to slightly resemble a car, so I thought I would put up a progress update.

Building the Frame

The first major component to be built on the car was the frame. I should say, rather, that it was the first to be started as there are always a few more brackets and things to add to it as the build continues, but the major structure of the frame came together fairly quickly.

Start of frame build

Here is how it all started: four lengths of 1" 16ga rectangular section steel tubing clamped to a build table. Seems very simple, right? It's hard to imagine at this stage that this will eventually be where your butt will sit as you travel down the highway.



Anyway, I had done some welding prior to starting the build but to gain a bit of proficiency I practiced on some offcuts until I was satisfied with the quality and consistency of the welds. Most of the frame was put together using an Oxy-Acetylene welding torch, though later in the build I got a hold of an arc welder and used that for most of the bracktets, suspension arms, etc.

Frame nearing completion

Eventually the frame started to take shape; here is a picture of it on its side while adding some of the side tubes. Going through and finding all the welds that I missed seems to be an ongoing process, and the frame in this picture is missing all of the brackets that have to be added to hold the suspension, engine mounts, and so on.

Taking apart the Donor

Ford Ranger donor being disassembled

While building the frame is a fun experience involving lots of cutting, welding, test fitting, and learning, the second part of the build process involved taking apart the donor vehicle. The donor had to be cheap which means it usually ends up being something fairly old, in my case a 1984 Ford Ranger. For those who have never taken apart a decades old car, it is a process which involves lots of oil and grease, rusted and otherwise stuck bolts, heavy lifting, and generally lots of swearing. In the end though I did end up with an engine, transmission, rear axle, prop shaft, and various other parts for $500.

Making the suspension

Suspension!

Once you have a frame and all the major parts you need sitting in your garage, a logical next step is to create the suspension, so that's where I went next. The front suspension is a double A-arm system, whereas the rear is a live axle with four trailing links and panhard rod.

While I do have the trailing links and control arms mostly finished, I still haven't sorted out the springs and shocks. My current plan is to use a rear shock from a Suzuki GSXR1300 (Hayabusa) on each corner of the car. These have a short travel of about 70mm, but a very stiff spring (730lb/in, or about 130N/mm) which will allow me to run them through a bellcrank with a ~2:1 motion ratio for an overall wheel rate of about 180lb/in. This will give the car a natural frequency just over 2 hertz.


Anyway, that's it for this update. There have been a number of other things done on the car, but I'll save those for the next update. I'm hoping to have a rolling chassis complete with working suspension, brakes, and steering completed before the end of Spring 2013. If you like this build or have any questions about it, feel free to leave me a comment.