Well, yesterday's work on the cycle was interesting......
To start with, I thought I would tackle the charging port in the tank.
On the Metro, I used a Marinco power inlet from the boat store. It looks nice and fit well where the gas cap was.
The local boat store closed up a while ago, and I seem to remember that plug being about $30, so I thought I would instead repurpose some existing material. But what would just be kicking around that happens to have a recessed male power connector on it? How about a junk computer power supply?
By removing a couple of screws and snipping the wires, I now have a FREE power connector.
There isn't a whole lot of space between the motocycle's gas cap and the main support pipe under the gas tank. The gas cap locking cover is actually pretty thick. To make everything fit, I needed to make the gas cap cover thinner. To do that, I removed the tiny screws from the under side to remove the lock tumbler, latch, spring, assorted washers, et. al.
I used a hole saw to cut out a section of plastic sheet the same size as the gas cap port. I then traced the power connector and Dremelled out a hole for it to fit through, and then hit it with some black spray paint.
After mounting the plug in the plastic disc, it looks like this.
And here's what it looks like in the tank.
I'm not quite sure how to mount it in there. The inside lip of the fuel port is sort of a weird shape and on an angle. I'm not going to actually mount the electrical jack until after the tank is painted. I may just have to use hot glue to mount the jack, or maybe 2-part epoxy.
The back side of the jack is just wires for now. I may wire on a standard female electrical connector on the other end of a short pig-tail, just to make it easy to plug in the charger. Hardwiring would make changing out chargers later just that much more complicated.
The other fun was that I took the brush-holder off the Etek motor.
I was talking on the phone the other day with a guy I know who works in R&D at a motor brush manufacturer. He said he might have some free Etek brushes kicking around from a testing project. I decided to pull the brush-holder off to take a look at the brushes and photograph them to send to that guy.
I now think of opening that as a Pandora's Box.
It only took three bolts being removed to take the entire brush-holding-unit off the motor, but did I know that? NOOOOoooooo.
It took 20 minutes of poking around in there with spring-loaded brushes shooting out and stabbing me in the eye before I figured that much out.
Unlike a typical series-wound motor, a pancake motor has brushes parallel to the drive-shaft. Imagine the brushes pushing against the face of a coin instead of it's edge. So, all the brushes point the same direction - DOWN. On a more typical motor, they all point towards each other.
Also, there are EIGHT brushes, and the style of spring does NOT let you pull the brush and easily hold it in the out position. I would need my pet octopus to help me put this thing together.
Here's what just one of the brushes looks like. It's sort of a wedge-shape. When you see the commutator, you will understand why.
Here's the motor with the brush unit removed, so you can see the commutator. It's sort of a copper hurricane of rotor. Since a spiral radiates out, there's more surface area per degree the further you get out. The wedge-shaped brushes take advantage of that.
Here's the brush unit. It's sitting upside-down, so what you see is that brush end, which would push against the commutator.
Now comes the fun part of the story.....
When putting the motor back together, I had to reinstall the end-cap bolts, which included washers and lock-washers.
I dropped a washer.... Into the motor.
Unlike a series-wound motor, which is only magnetized while current runs through it, this permanent magnet motor is ALWAYS magnetic on the stator. It literally has a ring of magnets on both sides of the rotor.
The washer was instantly SUCKED INSIDE the motor never to be seen again!
Any guess as to the spacing between the rotor and stator on this motor?
That's right, it's EXACTLY the thickness of a washer.
There was no way to get the washer out of there without a COMPLETE TEAR-DOWN of the motor.
So, now I had to take all of the bolts out (really keeping an eye on those washers this time!) At least now, I knew how to remove the brush holder as a single unit, and set it off to the side.
I would still need a bearing puller to get the motor apart. Fortunately, I was working at the
Milwaukee Makerspace, and knew one of the other guys was going to be in not much later. I e-mailed out a begging "please bring in your bearing puller!" e-mail.
Once the end of the motor was pulled off, it wasn't terribly hard to get the washer out. We had a stainless steel slim-jim (NON-magnetic!) that we slid in there to push the washer half-way out, they grabbed it good with a needle-nose pliers before pushing the rest of the way out.
Here's what the motor looks like without its cover.
The top plain silver ring is the back side of the stator. On the other side of it is a ring of permanent magnets.
Here's an inside view of the removed cover, including showing the drive shaft bearing.
Now, I got the joy of reassembling the whole thing. Again.
This time, I snapped one of the housing bolts. Arg! Then 5 minutes later, I snapped another one....
So a trip to the hardware store ( they are metric bolts - we American's never seem to have those in stock.... ) for 3 bolts, so I had a spare...
Apparently, M6 bolts can take nearly NO torque.
When reassembling, the bearing needed to be set down just a LITTLE further. I used a flat punch and hammer to push it down, so I could get the snap ring back in place.
Tap tap tap.... tap tap tap.... tap tap PUNCH!
The punch slipped, and went right through the bearing!
ArG! At least the hole wasn't punched right through the marking on the bearing, so I should be able to look up the number and buy a replacement.
So, that's the long story of why it felt like I spent the whole day on the motorcycle and got almost nothing done!
I did at least decide on how I want to mount the controller.
I would like most of the cycle components mounted in such a way that they are fairly visible. That way, when everyone is asking questions, I can easily point out the components and tell what they do.
I am going to mount a plate vertically, running longitudinally on the cycle, just above the motor. The controller will be mounted on that, so it's close to the motor, but also shows off the controller, and allows easy access to the serial port on the controller.
On the opposite side of that plate (visible from the other side of the cycle) I'll mount the main fuse, ammeter shunt, contactor, and anything else I'm forgetting right now!
The next big step (after replacing the motor bearing) is to mount the motor. Then I will see how much space I have available for the controller and other components.