7.4.11 :
mobi`dahon`pedal
leverage# toe-clips
7.4.11:
. cyclists can put more muscle into the pedal
either by standing up and jumping on the pedals,
or by pulling up on the steering while pushing down on the pedal
. they can also wear toe clips so that the pedals can be pulled as well
as pushed .
. mobi`s design requires the use of toe clips,
because the steering uses up-down motion for controlling the rear
brakes,
and the driver is reclined
. a back`rest could provide leverage for pushing on the pedals,
but toe clips are needed anyway for pulling up on the pedals,
and a back`rest would impede access to the driver`seat from the rear
while at the same time, access from the front would complicate
driver`shell design .
7.2.15:
. handlebar needs to be lifted upward
in order to pedal during an extreme turn,
so that precludes bolting the handlebars down
-- that's obviated anyway by the pedal straps .
rollerblade
reuse
7.2.6:
. roller blades might be good both as pedal straps, and as dog.guards
7.3.2:
. the rollerblade boots can be fixed to the pedals
only if something is found to replace the shim
that was previously provided by the wheels;
ie, the twin blades that hold the wheels are not side-strong;
one option is use bolts, and then keep that space open by nuts;
ie, a bolt with 3nuts,
or 2nuts and a load of washers,
or pipe cut to fit that space -- cheap and then the bolts that came
with the boots can be reused .
7.3.6:
rollerblade`shim
. as part of converting the roller blades to pedal straps,
found some plastic( easy to
cut ) pipe .
7.3.12:
rollerblade`ankle.fluidity
. for helping ankle to move, just cut a slit up the back of the lining,
and leave the top buckle undone .
7.5.3:
. the problem with a slit up the back is
that's a very active surface that is sure to need much fussing later;
easier in the long run to make a pair of slits down the sides .
7.3.19:
rollerblade`bonding
. boot needs tying more securely to outside of pedal
so it doesn't migrate around during pull
7.5.2:
. I was worried about using rope as the means for binding rollerblade
to pedal,
and trying a u-bolt instead worked ok,
but then I wanted the pedal to be halfway between the blade`s front 2
wheels
(it's currently over the 2nd one wheel from the front)
. I should get a new set of 4 u-bolts that are one size larger than the
ones I got for
securing the hinges to the trailer`frame .
leverage# pelvic
anchoring:
7.2.8:
. instead of tying down the handlebars,
simply add something to hold onto, or wear a seatbelt .
leverage#other
7.2.4:
stay-down handlebars [mis]
. in additon to having toe traps,
make the handlebars stay down so you can pull hard on them during a
down-pedal
. quickrelease straps can be added from each handlebar to the part of
the lockbox below it .
7.2.6: [obs]
. having 2 separate tie-down straps may not be releasing the
handlebars quick eno'
to handle the req that one must be able to quickly get out of the
vehicle
to do an emergency reverse .
7.3.11:
. the handlebars don't need to be raised to get out since deciding on
rear access;
but the handlebars must be routinely raisable for taking sharp turns
(eg, the safest left turn for a slow vehicle is to take a right,
and then at some quiet time take a u-turn ) .
hole in sole for
pedal axle: [obs]
7.2.9:
. use just pedal`axles and then wear earth shoes (which have the
thickest part at the ball of the foot)
and drill a hole in the thickest part to insert axle into sole .
...
. even with grease in the hole, there would be far more resistance than
grease on bearings .
advanced design#
path.shaping
7.4.27:
nautilus-cammed linear system is max efficient
. I was noticing that what makes rotary pedaling inefficient is that
tangency is lost;
ie, when near the top or bottom of the stroke,
the pedal force is pointing down when the tangent would from the side
. hydraulics can allow pushing in any direction,
so that the driver`s right leg acted normally, while the left leg did
the work from the side ..
. there are picts [@] hpv`hist showing linear pedal systems
and the idea behind that is simpler, cheaper,
and lighter than what hydraulics could offer
. with nautilus weightlifting cam designs,
you could do even better than linear,
because legs have better leverage when the joints are not bent much,
so that's when you want the cam to have shorter diameter,
where it puts the leverage into high gear .
-- that should maximize in ways that are obvious but unavailable due to
patent complications ?
tech:
. there's elliptical chainwheels that are like nautilus,
but they are trying to make up for not having linear drive,
ie, since the force is downward, they shape the chainwheel so that
most of the work gets done when the pedal crank is near the side
. a cammed linear system would push a rack across a pinion that was
cammed,
p90 = pinion at 90deg;
. p0: left.knee`angle is accute; so p0 diameter great,
when left.knee`angle = 45, then pinion diameter is decreasing
at a rate that takes into accout the other leg`s pull power efficiency
curve
. when the left.knee`angle=0, p`angle =180,
because after both legs are done, p`angle has to do a full 360 (2*180)
. p180 is approached p`diameter is rapidly increasing,
so that the diameters are greatest at p0 and p180,
but the rate of change differs
. perhaps the optimal way even when considering weight,
is to give each leg it's own rack&pinion so that
the left leg is getting a very short pinion`diameter all the way to
p180,
while the right has a rapidly increasing pinion`diameter near p135,
so that while left is short at p180,
the right leg is maxing the pinion`diameter then .
7.5.2: cable machines
. as sea stories.sg
points
out, one way to provide a linear pedal drive
is to have a cable on a ratchet driving a flywheel,
. the cable is spring loaded so that when you're done pulling on it,
then it rewinds auto'ly .
. that is useful in a rowing machine design,
but in the typical system of pedals with toe`clips,
the cable`return can be more efficiently impl'd by a leg`reverse cable .
7.5.6:
mobi`dahon`pedal
. the seatbelt might be more effective and less confining than a pair
of backstraps
. might be easy as threading a hip belt through the seat`s anchor bars .
