A unicycle for a push stick, motail, roller cycle...

[John Doe]

Come to think of it, a small wheel (12" or 16") unicycle looks almost
perfect for the frame of a push stick. And then attach a platform or
suspension for a durable cordless drill to drive the wheel. And, if
possible, have a seat attached firmly to the skater so that the thing
can be used without holding onto handles.

[John Doe]

A unicycle frame is to be used for a push stick for in-line
skating (FWIW, I think my favorite name would be "motail" spoken
with a Southern drawl, a contraction of "motor tail"). You can see
a demonstration video on the Internet or YouTube called "roller
cycle". Their "grass" version video is outrageous. The user pushes
with his feet, that is silly, they are trying to show that you can
get exercise. Your heart gets plenty of exercise, it is thrilling
fun. Mine must be electric, it cannot be a noisy gas powered
version. I built one with SLA batteries that was much too heavy,
it broke twice.

A unicycle might be nearly perfect for the frame. The only thing
I won't use is the pedals. If possible, I will make a wraparound
body/leg attachment at the seat so that holding onto the push
stick is unnecessary. Otherwise, the seat will be removed and a
steer horn piece of aluminum tubing will be put in its place, like
sitting on handlebars (like the roller cycle video). I'm going to
attach a high-voltage/quality cordless drill body to one side, and
its battery to the other side (for balance). The controller will
be on the handlebar.

Looking at the unicycle pictures... The fork connection to the
axle uses two heavy-duty bolts, that is exactly what is needed for
mounting the drill, to keep the drill from spinning. If the
pressure on the fork is too much, the drill clutch pressure can be
reduced. The force on the spokes will probably be no more than
usual unicycling, and there will be no other bending pressure on
the forks or on the seat post.

[John Doe]

For my first attempt with a drill, I might go with a Panasonic 18 V
with 3.5 amp hour NiMH batteries. With a 16 inch tire... Low speed
starts at 70 rpm, that is less than 3.3 mph. High speed starts at
about 10 mph, obviously I would have to start skating first in order
to use that. High speed tops out at 60 or 70 mph, obviously that is
unrealistic at 18 V (or my skating ability).

The real challenge will be connecting it to the unicycle fork.




EY6450GQKW Features:

* 18V Cordless Drill & Driver
High Capacity 3.5Ah Ni-MH Battery
* Lightweight
* High Power
442 in.lbs. of Torque
* 65 Minute Charge
* 2 Speed Gearbox
Low: 70-430 rpm
High: 240-1500 rpm
* 15 Stage Clutch Plus Drill Position
* 1/2" Keyless Chuck

[John Doe]

Got the 16" wheel unicycle today. Removed the cranks. That required a
gear puller. The square taper axel sticks out farther than necessary,
so it will be cut short. Either side of the axel can be driven by the
cordless drill.

[John Doe]

The DeWalt 18 volt compact drill motor housing is no larger or
heavier than the 14.4 compact version. Removed its chuck. Used a
cutoff tool to cut off one end/side of the axle.

[John Doe]

Chopped up the drill chuck, to see if the metal part can be shaped
and used as a long nut on the arbor/shaft. Figuring out how to
connect the drill arbor/shaft to the unicycle axel.

[John Doe]

Removed (cut and ground) a ton of metal from the steel part of the
chuck that screws onto the arbor/shaft, to make it into a long nut.
That will give the arbor some thickness, so that it can be used to
drive the unicycle wheel.

[John Doe]

Ground the arbor/shaft and the unicycle wheel axle so that they fit
together like a large flat head screwdriver and flat head screw head
(17 mm diameter).

[John Doe]

Almost finished. Need to align and secure the drill body to the
unicycle axle. Total weight should be no more than 14 pounds.

I don't think this thing is going to push me up hills, but if it
pushes me over 10 mph on level terrain, that will be plenty of
fun. I skate where manual pushing is sometimes very difficult.
Distance is another issue, but that's just a matter of upgrading
the batteries. It partly depends on what DeWalt does with its 18 V
battery technology (assuming the 18 V motor is sufficient).

One thing that makes a Motail so cool is that you retain most of
the flexibility of in-line skating, while getting rid of the
stroking/pushing part. For traveling light on streets and
sidewalks, nothing beats in-line skating.

[John Doe]

Not being light enough to easily carry, it really needs to be
freewheeling. To be continued...