To assemble the unit, you have to start with screwing the precharge button and the master switch onto the front of the box. They connect to each other with a JST-SM connector, which I use for all my signal connections, and are great except for the fact that they're not waterproof. The LED in the button is connected across the precharge resistor, so that it lights up in proportion to the current going through the power resistor. That is, it would light up when you first press it, and then fade as the controller's capacitor charges, except that I made the assumption that the button had a resistor built in for the LED, which it does not, and so it's burned out now.
Next come the bearings, which are mounted with #4 screws, instead of the #6 they were made for, to allow them to be aligned and make up for my inaccurate machining work.
After that, you install the intake fan, which blocks the switch from being removed. First you install the grill onto the output side of the fan, which keeps wires from getting in the blades, and then bolt the fan into the enclosure, with a filter to keep the dust and mud out.
The shaft goes through one bearing, you slip on the thrust bearings and shaft collars, and then you push it through the other bearing. I plan on adding wave washers to the sandwich to reduce the vibration of the thrust bearings. The shaft blocks some of the nuts on the fan, making that a pain to install or remove without removing the shaft. This is as far as I disassembled tonight, and so I should have pictures from here on down.
Next, the motor. Can we take a moment to enjoy those beautiful copper windings?
The brackets for the controller get attached with 4 #6 screws tapped into the box. Yes, I know the screws don't match, I didn't have enough pan heads.
To protect the electronics from road spray, I used a 4" fence post cap to cover the bottom, with a hole in it for the wires to pass through. I have to drill some more holes in this cap, to act as exhaust for the fan in order to route the air past the motor, and then cover them with a filter to keep the dust out. Unfortunately, there's not enough room between the top of the box and the bike's top tube to put a fence post cap on top, so I'll have to make a flat cover. The bottom cover is connected with 4 #6 screws, tapped into the aluminum. Did I mention I have come to love tapped holes? Not having to deal with nuts is amazing, particularly in situations like this where there is no way to hold them in place.
Although I haven't exactly been keeping to the schedule I set, the bike has been going surprisingly well. I hit a number of stumbling points where my plan didn't quite work out, but it feels almost done. I had a fun moment earlier today of sitting on the bike, gunning the throttle, and hearing the whine of the motor.
As far as what's left, there's just a few things. The big one is that I need to get the pulley machined. I also need that #410 sprocket, and a longer bottom bracket so that the chain doesn't hit the side of the drive unit. I need to secure the battery box to the bike, and then I should be able to ride it.
I'm probably going to have to build a belt tensioner, for which I have the design and the idler pulley, but I'm going to wait and see if it's necessary first. Lithium Ion batteries are probably in this bike's future, although the initial tests of the laptop cells are not looking too good. Freewheels on the crank and jackshaft would be nice, because they would allow me to motor without spinning the pedals, and pedal without spinning the motor, respectively, but like I've said about the batteries and many aspects of this project, I think I'm just going to get it working first.
I also recorded a video of me showing how to turn on the bike, and that the motor does in fact spin when I turn the throttle, but it came out shaky and the audio was poor. I'll try again tomorrow.