Another day of work and the Electric X²/2 is within a few hours more work of movable! Electric X²/2 is now the official project name, and it is a play on the original Sharper Image Electric X2. It’s not mathematically sound, but you shouldn’t be reading this page for mathematical discourse anyway.
Pics!
We begin today with a picture of my disaster area of a work bench, as well as a handy creative use of the hand drill and the drill press at once. There is a 1″ wood spade bit in the chuck, and a piece of aluminum in the vise. The spade bit does not go through the aluminum. Solution? Brute force machining using the much more powerful corded drill, transmitting power to the spindle through a 15/16″ socket. I figured that with the drill cranking at full force the spade will eventually melt through the aluminum and be on its way.
This was not what happened. Unfortunately, the spade bit (which should never be used on metal anyway, especially not like this!) just blunted out completely and polished the aluminum at a depth of about 1/16″.
I left this full size (3000 px wide, 3 megs, blame my carelessness with the quality slider) if you want to investigate the metallurgical structures of aluminum. I think I almost snapped the table right off the drill press by slamming the lever so hard.
Therefore, I had to resort to the OTHER brute force machining. Drilling holes in a circle, then bridging those holes with a Dremel drywall cutting bit. This worked very well.
Here is the throttle body with the potentiometer mounted. It will be clamped to the handlebar. Why couldn’t I use a stock, well-built, easily purchaseable throttle? Because the handlebar is a weird diameter nobody makes accessories for.
Complete throttle body with aluminum thumb lever thing, which will probably be dipped in something soft. I couldn’t believe that none of the random mechanical tidbits I stockpile had a single usable torsion spring. In the end, I faked it out with a tension spring wrapped around the resistor shaft. The spring anchor screw was dug out from my hardware trap, and is an odd standoff-screw at the most convenient height possible. This screw also acts as a travel limiter.
I found that using a 10K pot was better than a 5K as perscribed in the original servo tester circuit since it made the useful travel range smaller; that is, more usable with a thumb lever. The bottom travel limit is the potentiometer body itself, and corresponds to 0% power on the controller. The top end travel limiter is the screw, and it stops exactly where “full throttle” on the controller is. The controller automatically shuts down if it gets past this angle, causing the electric brake to kick in and me to probably fly off. Therefore, the stop is right before this limit.
Mounted on the right side handle bar. It’s nice when things just work.
Working on the switchbox. I had to yank the big 10 gauge cables through the holes in the box with pliers, because the holes weren’t quite big enough. Originally, the holes were for LEDs – a red one for “low battery” and a green one for…well, something other than low.
I had to break out the huge 15 inch long 100 watt iron to solder the big cables to the big relay terminals.
Power meter tape-welded to a bent metal plate screwed to the completed switchbox, which has been mounted back in its original position. It’s a nice fit. The angle could be a bit shallower, but I won’t take it off and adjust it again for fear of breaking things.
Notice the white wire next to the thick red and black ones. This is actually a four-conductor cable salvaged from a computer mouse. Conveniently, it was six feet long, and had all four conductors I needed – +12v for the meter, and three wires for the throttle. There’s so much convenience on this thing it’s not even funny. Actually, it is.
One more interesting feature is that the red and black wires are both on the battery negative side of the whole electrical system. Why? Because I had six feet of red and black zip wire, not six feet of black and black. Interesting things will happen if I wire this red cable to positive, such as dead shorting through the relay and making a huge smoke cloud. Watch for this.
Dummy motor says everything is working as it should!
Now the only thing left is to get another slab of 2.5″ aluminum and some more servo leads. Then it could be done. By this weekend, even.
Watch for a MAJOR BUILD DISASTER in the near future! All my projects have Major Build Disasters around now, and I don’t think this is an exception!