Today's goal was to finish the hitch system by fabricating a U-bracket for the trailer, like the one I built yesterday for my bike. The second time always goes more quickly than the first, so I wasn't really surprised that this bracket went together smoothly, even though I used a slightly more complicated design.

When I measured out the pieces, the cross-brace turned out to be twelve inches wide, three inches more than the bike hitch's cross-brace. I had been worried that the force on the center of the crosspiece would be great enough to cause it to bend, but convinced myself that the inner angle-braces would be enough to prevent this. With the extra three inches in the span, however, I was no longer so confident, and decided to double up the crosspiece. I had to do a little careful filing to get the pieces to fit as tightly as I wanted them, but it all worked out and I think it will be as sturdy as it needs to be. It is probably over-engineered, actually, but I really don't want to come back next month and rebuild it all over again. Something else can break next time!

After I had the hitch finished, I did a little more electrical work. I decided to use the last of the four switches on the panel to control the strobe light. The strobe runs on 120VAC power, so it needs to plug into the inverter. I decided to mount a standard AC electrical socket on the upper deck of the machine and run its hot wire through the switch. I had a little trouble finding a suitable socket; I wanted something that I could surface-mount, so I wouldn't have to cut holes in anything, but I didn't want anything as bulky as a standard two-socket outlet with a junction box. I ended up buying a small ceramic light bulb base and screwing in a plug-adapter. It's a little bit of a kludge, but it is the right size and looks pretty, and that of course is what really matters.

The hitch system is one of the components that completely failed at Critical Massive. I originally bolted two parallel rails to the bike and to the front swivel wheel, thinking that the bike would turn and take the trailer with it. This did not work at all: the bike could only turn about ten degrees before it would bind up against the inside of the rails. It is clear that the pivot point needs to be much farther forward, as close to the back of the wheel as possible.

I set out tonight to improve the hitch system, in preparation for the Phoenix Festival this weekend. I decided to cut the hitch rails in half, mount a cross-brace onto each pair, and build a swivel between the braces. While I was at it, I decided that it would be really nice if there was some kind of quick-connect system so I didn't have to mess with a bunch of bolts every time I wanted to attach or detach the trailer. I had to visit Home Depot for another piece of aluminum stock and some hardware, so I only got the bike half of the hitch system finished tonight; I plan to build the trailer half tomorrow.

I started by cutting the rails to the minimum length that would still clear the taillight. (I wanted to be able to fold the hitch up and out of the way when I wasn't using it, or I could have made the rails about three inches shorter.) Then I cut some L-brackets, drilled a bunch of holes, and bolted the rail to the cross-brace in a sort of T-shape. I repeated the process for the other side, then put the 5/8" eye-bolt in the center, and that part was finished. Of course without some vertical support it would drag on the ground, so I put a small eye-bolt in the top, threaded a section of cable, and used a carabiner clip to attach it to the underside of the carrier rack. This also provides the fold-away system: I can swivel the hitch up and clip its cable to the seat instead, holding it out of the way. The hitch is still removable, and it's held on with wingnuts so I don't even need any tools to remove it, but I figure it will be much more convenient if I have the option to leave it on.

The trailer side of the hitch will work pretty much the same way: I'll bolt a cross-brace onto the existing rails, making a U shape, then stick a great big eye-bolt in the cross-brace. I'll use a screw-link to connect the two eye-bolts, so the pivot will be a three-link chain where one link is fixed to the tractor and one to the trailer. The screw-link is really easy to open and close, so connecting and disconnecting the trailer will be no hassle, and won't require any tools.

One frustration I encountered at Critical Massive was an unexpected degree of difficulty convincing the outriggers to slide into their sockets, and then an equivalent degree of trouble coaxing them back out again. The two-by-fours I used were snug but comfortable when I first assembled the system; multiple coats of paint, however, added almost too much to fit. I decided to improve matters by grinding off the paint and a layer of wood along the sections of the outriggers that fit into their sockets. I'm not sure how much thickness the new layers of paint will add back, but the two-by-fours are visibly thinner in the sections I worked on and slide in and out very smoothly, so I think it will be an improvement.

I ordered two more electrical components for the rave-o-matic today: an American DJ Mini Starball and a Chauvet Mini Strobe. I originally wanted a mirrorball, but mirrorballs are not particularly rugged, and they need an external spot light. I could probably rig something up, but keeping the mirrorball aligned in the spotlight's path - not to mention keeping it from swaying around and bashing into the support pole as I towed the machine around bumpy roads - seemed like more work than I really wanted to get into. The starball will definitely be less work and I think it will look pretty cool on its own. I'm going to mount the strobe on the laser platform, pointing down at the ground; it should light the dance area up pretty well without blinding people as much as it would on the body of the machine. I had been thinking of some complex timer arrangement, so the strobe would go off every few minutes and spend a few seconds firing rapidly, but from my experience at Critical Massive I don't think it needs to be so complex. I'm just going to mount a remote power switch on the body of the machine and control the strobe by hand.

Aside from the red laser, there isn't much color on this machine. The blacklights are kind of purplish, but they don't really put out much color of their own. I'd thought of pointing colored spotlights at the mirrorball, but the starball I'm using instead just puts out white light. This might not turn out to be a problem, but if it ends up looking too plain maybe I can install some colored blinkies underneath the body next to the outrigger mounts.