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Point 1. Due to a radical (100%) miscalculation, I have two
identical battery-operated electric drills. They are both
fairly normal, with a squeeze-trigger which progressively
increases the speed.
Point 2. There are various battery-driven electric skate-
products. Most of them are
Point 3. Flexible drives (consisting of a flexible core
inside a flexible sheath - as used by old-fashioned car
speedometers) are cheap and simple.
Point 4. I also own a pair of rollerblades, which are seldom
used because, frankly, they are only really good for going
So. It should not be beyond the wit of man to produce a
modified rollerblade wheel that engages with a flexible
which in turn has a hex-bit end that connects to a battery
drill. Any rollerblade owner (such as my good elf) could
simply swap out the rear wheel on each roller blade for one
of these modified wheel/drives. Then armed with two
common battery drills, one in each hand, - gadulka! -
propulsion is yours for the
Motor roller-skate [xaviergisz, Jan 12 2015]
His lordship, seventh picture down...
[normzone, Jan 13 2015]
[evilpenguin, Jan 13 2015]
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||Re. [xavier]'s link - hmmm. The linked patent is sort
of this, but also not. The patent seems to be for a
complete drive unit, rather than for a simple
modified wheel and flexible drive to be used with a
||Also, the patent drawings show 52 parts in
considerable detail, whereas my invention has only
two parts: replacement wheel; flexible drive. Also
also, the patent idea seems to be properly worked
out, whereas mine is not.
||I just posted to show that flexible shaft driven roller skates were possible (I had initially doubted whether a flexible shaft would be able to transmit enough torque).
||Ah. That is a good, and reassuring, point.
||Sigh... So much Wile E. Coyote potential here. If only Chuck Jones had been alive during the battery drill era.
||There is some matter of torque and speed balancing to work out.
||1. Drills are worn in belt holsters, one on each hip.
||2. Flexible drives run alongside legs - attachment bands may be necessary.
||3. Drive mechanism clamps on outer sides of rollerblades, driving rearmost wheel by edge friction. Choice of sizes of drive wheel gives speed reduction and/or torque management.
||4. Please post the You Tube video of this.
||Don't the old kind of dentists drills use flexible drive shafts?
||Baked. see link... good idea though
||Awesome link EP. I should've known Jamie would try something like this. But what happens when one battery runs a little flatter than the other?
||One could test the concept by affixing a wheel (perhaps you have some extra) to the drill and then affixing the drill at an angle to the end of a long, gondolier-like pole. One should be able to wear unmodified rollerblades and use the pole and drill for propulsion.
||Speed could be increased by pressing the pole and attached wheel more firmly against the ground. One would lean back, bracing the pole under ones arm and so forming a tripod. Braking would be done by reversing the pole, either by spinning the pole in your hands or swinging it quarterstaff-style across the body to the other side such that the wheel turns in the opposite direction.
||I was not clear whether you intended to use both of your drills for this project. Presumably you need one for regular nonpropulsive drilling. But if both are to be used, you could attach them to forearm crutches and have one on each side. For double the speed.
||If it turns out that the drills have inadequate torque to propel your bulk, you can quietly take apart the poles and your rollerblades will not bear evidence of this experiment.
||I still looking for the video, but I remember Jamie Hyneman making these skates that used Drills he held in his hands that utilized flex shaft cables. The video I found must be another version of his.
|| 1. Drills are worn in belt holsters, one on each
hip. // Yep.
|| //2. Flexible drives run alongside legs -
attachment bands may be necessary. // Yep
|| //3. Drive mechanism clamps on outer sides of
rollerblades, driving rearmost wheel by edge friction.
Choice of sizes of drive wheel gives speed reduction
and/or torque management.// Nope - requires too
much additional hardware. I want a regular wheel
(which can be used as such) but with a hex-style nut
sticking out the side, that can be driven.
||// I want a regular wheel (which can be used as
such) but with a hex-style nut sticking out the
side, that can be driven. //
||Unfortunately I think you'll need to modify your
standard roller blades to make that work well. It's
probably been more than a decade, but I once
swapped wheels on my roller blades, and if I
remember correctly, the bearings were embedded
in the wheel with a 1/4" non-rotating shaft
through the center connecting these to the skate
frame. So it seems to me that to accomplish this,
you'd need to have a coaxial shaft with the
outside diameter = 1/4". That sounds like it might
be a little weak for the job.
||Of course the skates could me modified to move
the bearing from the wheel to the frame and have
a rotating axle with a hex head, but that would
take significant customization of the skate.
Definitely not a universal adapter.
||hmm, afaik, drill motors are pretty puny. Flexible drives
are pretty inefficient, as are roller blade wheels on
anything other than perfectly flat surfaces. Also there's
no mention of a clutch/freewheel arrangement, meaning
that when you let go of the drill trigger, either the (roller
blade) wheel locks up or the drill spins around in your
||However, rollerblade wheels are about 80mm in
diameter, so about 250mm in circumference, 10mph is
about 4.5 m/s meaning you'd need about 1000 rpm,
which is right in cordless drill range, so you're in good
shape there. You would need both hands in use at all
times, meaning that a cheery wave would immediately
spin you around your now immobile skate.
||If I could suggest a modification or two... a cordless drill
is about 5lb, the extra mechanicals about 2 lb, a pair of
roller blades about 10lb and the requisite neon elbow
armour another 1lb. so in the 20 lb range. By simply
omitting the cordless drills, roller blades and all but two
of the wheels I can see benefits in simplicity. Efficiency
would increase if you made the wheels a lot bigger,
pneumatic tires would add comfort and capability over
uncooperative terrain. Standing is ungentlemanly,
especially standing on top of large diameter wheels, so
perhaps a framework, complete with a pleasingly waxed
leather seat could be used to suspend the passenger
between the wheels? Perhaps even the relatively high-
tourque lower appendages might be used for propulsion?
||If someone were to make propellers that fit into drills...
then you'd be onto something, with one in each hand you
could pull yourself along like a latter-day DeHavilland
Mosquito, or find a companion and be a Lancaster while
whistling the Dambusters theme.
||A backpack-worn leaf blower can provide a very useful amount of
thrust to a cyclist ...