Hi everyone, after returning from a major adventure, driving this guy from Baltimore to Minneapolis and back:
![Image](http://www.logical-space.org/img/tr3.jpg)
I decided to stop planning and just dive into a Locost build, and this is the start of the log. There are some important questions about moving forward at the end of this post, but first some pictures.
Here's the donor, a 1994 MX-5 with Torsen LSD that I'll be bringing down from PA this month:
![Image](http://www.logical-space.org/img/miata.jpg)
I bought enough 16-gauge A500 steel tubing for the Vodou plans, and just started chopping and welding. Here's the current state of the frame:
![Image](http://www.logical-space.org/img/full_view.jpg)
Working in a tiny row house basement, and instead of a full assembly table, I tack-welded the lower rails while clamped to 4-foot pieces of I-bar, and use an abrasive chop saw and a digital angle-finder to cut and fit the pieces:
![Image](http://www.logical-space.org/img/on_tablesaw.jpg)
Some weld close-ups, starting with one of the earliest:
![Image](http://www.logical-space.org/img/acute_ang.jpg)
A basic flat join (most of the outer welds are like this):
![Image](http://www.logical-space.org/img/corner_weld.jpg)
The open edges of a tube:
![Image](http://www.logical-space.org/img/tube_end.jpg)
An obtuse angle:
![Image](http://www.logical-space.org/img/obtuse.jpg)
And probably most importantly going forward, my current version of a decent fillet weld versus not-at-all-decent:
![Image](http://www.logical-space.org/img/decent_corner.jpg)
![Image](http://www.logical-space.org/img/bad_corner.jpg)
As you can see, I'm not much of a welder! The flat outer welds are easy enough, but the rest can get pretty messy, and I've been grinding them off, making multiple passes, etc pretty freely.
Before pushing ahead with the diagonal bracing and beyond I wanted to be sure I'm not too far off-track, because I have
no sense of the acceptable tolerances, weld quality, etc. None of the paired angles (RHS to LHS) differ by more than about half a degree (according to my 0.3-degree-accurate angle-finder, so maybe just say "all are within a degree"), generally centered on the "correct" Vodou angle. From a rear corner to the opposite front corner, it twists maybe 3/16" (i.e. if I push down on one corner, that's how much the other corner rises). Finally, as you can see from these pictures, there's a lot of variety in the weld quality (in the first image, I doubt I can weld in that extremely-acute corner at all):
I'm using this project to learn the basics, so perfection's never been on the table, but given these angles/twists/welds, can it become a decent build? My hope is to correct for geometric issues when attaching brackets, positioning the differential mounts, etc. For the welds, I think I'm getting better pretty quickly and can go back over the rougher points, but at what point does heat cycling become the problem? Do these frames have some redundancy such that regularly inspecting for any cracks will catch them before serious failure?
Thanks for any and all feedback! I'll keep updating this thread as things progress, and perhaps create an external (full) gallery at some point.