Day 84 and 85 - More fender motorization

I spent a good chunk of time drilling various bits of metal and wood, and making sure everything was all lined up.  Finally, the wheel assemblies were ready to be bolted to the rest of the frame.

The problem with that much frame, however, is that there are not a lot of places to mount casters.  I got a set of small 2" casters at Lowe's and placed them temporarily onto the topmost and bottommost wooden struts using self-tapping screws.  I then eagerly took the fender outside for a spin.

After a few minutes of loud, rough trundling, one of the back casters snapped off.  As you can see from the photos, the screws were pretty close to the edges of the wood, so there wasn't a lot holding them into place.  A rough, pebbled cement driveway extends from my townhouse front door at an angle, and that also contributed.

The next day, I described some of my progress to some of my chums at work, and one of them (who builds robots) put in his thoughts on what I could also do.  He suggested reinforcing the third mounting point on the motor casings, which I hadn't yet done.  Since the wheels are mounted on parallel metal beams running the length of the fender frame, sufficient weight placed on them could splay them apart.

So I pondered a bit on how I could solidify this, and came up with adding a length of 5/8" solid threaded rod, bolted on either side with nuts and locking washers.  It's pretty rock solid.  In fact, I had to detach the wheels to even get the rod in place.  Once re-assembled, it wasn't going to splay at all.

Another chap had inadvertently eavesdropped on the conversation at the point when I was talking about the crappy urethane casters, and not knowing where to get ones that would really be able to handle a nice solid load.  He mentioned a store I hadn't even heard of that's still here in Seattle, called RH Brown.  I'm glad he told me about them!  I went there right after work and bought 3.5" and 4" rubber casters and took them home.  I didn't yet know what size I was going to use, and they said I could take back the set I didn't use for a refund.

There was no place on the frame to put them, initially, so I decided that I was going to trim some of the workings off of my monster assemblage.  I took my metal-cutting blade off of the miter saw, threw it onto my circular saw (same size blade), and cut off the upper and lower parts of the square steel tube on which the wheel motors are mounted.  I then unbolted that and the uppermost and lowermost wooden beams.

This cleared a large area for me to add the new casters.  In order for them to be just about level with the main tires, I needed to mount them on top of two 1/2" pieces of plywood.  I chopped up some offcuts, and secured everything into place, this time with 5/16" hex-bolts (and not self-tapping screws).

It looks a lot less complicated down there, now.  Still weighs in at a hefty amount, though.  We took some video of me test-driving it, but because it was so dark, it didn't turn out very well.  Also, I need to sand off a bit from the front plywood caster mounts, because at times the middle tires weren't in contact with the ground.  On a flat surface, this might not matter, but I know I'll hit angles from time to time.

Video of me trundling around likely to be posted soon!