Shuttle production model build notes

Hey amigos, I know it's been a while since I've rapped at ya.  I've been working on starting up a thing, which you probably already know, because if you're reading this, you're friends with me.  And if you're not friends with me, and you're reading this: welcome!  I am a handsome and accomplished man!

But, in between hacking together React widgets and swearing at JavaScript for having ever been invented, I put together a new prototype, which I am not thinking of as a prototype, it's really a test-build for a production model.  Here's the goods:

The entire thing is 8 feet long, made of two 4 foot halves.  The framed ends are 6" by 6" 0.120.  1/2" wide on the ends, and 1/4" wide on the parts in the middle.  These are held together with 1/2" square tube, welded onto the frame ends.  The rails are made of 8 foot long segments of 1/2" EMT electrical conduit.

The shuttle is similar in design to the last one, but the rail holders are solid tubes, and much larger diameter.  The 1/2" tube rails are much stiffer, and the rail holders are just welded onto the pipe holder in a single line.

The rails are held to the frame ends by 1/2" metal rod which is welded onto 1/2" wide segments of steel right angle.  These are screwed into the frame ends which are 6-32 tapped.  I broke my tap off in one of the frame ends at one point, and just used a cold chisel to break it off, and moved the hole.  It turns out that these tap extractors don't really work, at least not for a tap that small.

When the motor and chain drive are installed, I'll wrap the whole thing in 22 gauge steel (which is the thinnest I could get from Bay Metals that wasn't galvanized.)

Need to attach a hose and check how the running actually works, then buy and install a chain drive.  But, it's coming along.  The chain drive will be fun.