(Crossposted)
Even though the devices discussed in a prior (metalworking) thread were not used in this design, they are greatly appreciated and probably will be in other designs. The objective is to make a very light weight electric powered skate, scooter, whatever, that will traverse rough terrain like my 100 mm in-line skates do. The following is only one of many possibilities.
Various resolution pictures in: Newsgroups: alt.binaries.phish
I actually machined the motor shaft gear to remove about 1/4" of it, ground down to about 1/8" diameter. Used a rotary tool and spun the motor against the rotary tool. You can zoom in on one of the pictures to see that. It's reasonably uniform IMO but not smooth.
With the exception of me (without real tools and experience) grinding the shaft gear, the motor drive design is simple and easy to build. No alteration to the skates is required. The only parts are the motor, a plate to hold the motor, and a small rectangular thick steel washer to hold the motor plate on the other side of the skate frame. For contact with the skate wheels, an aluminum tube is placed around the motor shaft gear (padded with heat shrink tubing, and superglued). The rest (unseen) is just the cordless drill body with battery, switch, and wire/connector.
Not much ground clearance, but I'll use a flexible shaft from the motor to the roller drive if this particular design is repeated. I really like the fact that the roller drive is between two wheels which counterbalance the thing (and increases traction), putting little if any lateral strain on the motor shaft. The roller drive can be placed between any of the wheels, its modular on that skate frame. The roller does turn both wheels in the right direction :D
Lots of power using the 36 V cordless drill motor. Without gearing, top speed is 10 or 15 mph I guess (I'll measure that later). It goes from zero to top speed quickly. Apparently the roller drive works at least well enough for the application, the roller driving the wheels and the wheels driving the skates. But that depends partly on how long the scooter wheels last.
Also possible is using one 18 V cordless drill motor on each skate with one DC motor controller controlling both. Not sure how to do that but it sounds like a lot of fun.
Apparently the "electric breaking" only kicks in when the motor switch is completely released. Will see if skating overdrive damages the DC motor speed controller.
First use was a riot, as expected. Lots of protective gear but without falling.