Next Generation of Scooter

[Aquamaniac]

During a recent R&D project, I got to thinking about applying leading edge technology to diving. We have already seen the benefits of HID technology in our lighting systems. The efficiencies have been increased by as much as 80% giving us very small power supplies, and very bright lights.

What if we were to apply leading edge technology to scooters?
We have already produced electric motors utilizing HTS Superconductor technology, in fact the navy is presently initiating a Ship Propulsion Program, utilizing ASC Air Core Superconductor technology.
This has reduced the size of the motor by 60-80% with significant increases in efficiency. ASC Air core windings do not require an Iron, and the conductors are 100 times smaller than a copper conductor of the same current rating. This makes for a very small, very powerful motor that is very efficient.
Apply that kind of technology to a scooter, and we could have a scooter that is the size of a football, that will run for 12 hours!

Now of course at present this is all “pipe dreams” stuff, due to the fact that the cooling system would be the size of a long body Gavin, and the cost would be a couple of hundred thousand dollars.
But, latest research has increased the temperature requirement for superconducting from 4 degrees Kelvin to 77-100 degrees Kelvin, this has removed a major roadblock, and allows us to now produce motors that are economically viable.

As we develop better systems, we edge closer to the Superconductor Motor being the norm.

Who knows, one day Suunto may come out with a wrist mount Scooter!

Dave

[bmazin]

The efficiency of the motors are already very high. For example, Jetboots, which use extremely good brushless DC motors, have motor efficiencies of >90%. Going to a superior motor technology would buy you very little - most of the battery power is already going toward its intended purpose, moving the diver.

The largest potential performance gain is in better battery technology. Jetboots weigh about 22lbs, but have similar performance to a apollo av-1 class scooter (~50 lbs). Some of this weight savings comes from the lighter DC motors, but the vast majority is due to using NiMH batteries instead of lead acid. Lithium ion batteries double the performace of NiMH - look for these on the horizon.

Ben

[Aquamaniac]

Ben, I think you missed my point.
I was not talking about motor efficiencies.(although HTC motors boast 97.7%)

Jet boots are a novelty, with standard off the shelf DC motors.

[Scubaroo]

bmazin,

You really should disclose your position as President of Mazin Submersible Technology, Inc., makers of Jetboots, if you're going to talk about them here.

other Ben

[edit] okay, I see you already have in another post!

[Fetch]

Actually, reading your post:

The only thing that would be reduced in size would be the motor (not an inconsiderable size savings, of course). Battery size would be the same for (slightly more) runtime, and for 12hr runtime the battery size would be considerable, even with a SC motor.

I tell you what, if you find a way to magnetically bottle a miniature black hole, you can use it to convert matter into energy, thereby greatly increasing the efficiency of whatever material (sea water?) you use as a battery.

Yeah, that's the ticket...

jeff


Aquamaniac once bubbled...
Ben, I think you missed my point.
I was not talking about motor efficiencies.(although HTC motors boast 97.7%)

Jet boots are a novelty, with standard off the shelf DC motors.

[bmazin]

I though my Jetboots affiliation was known from previous posts here - sorry I forgot the usual sig. I used Jetboots as an example because I know the numbers for them better than other systems.

The point remains that motor weight/size/efficiency is currently less of an issue than the corresponding properties of batteries. Bottom line - motors technology is good, battery technology is not. In Jetboots, motors = 7% of total weight, batteries = 60% of total weight. Volumes of the two scale roughly the same way as their densities are similar.

Superconducting motors are being investigated for large motors for the reasons aquamaniac mentioned. Here is a quick motor summary as I see things:

conventional DC motor (all scooters except for Jetboots): Magnets on outside, wiring on rotor. brushes carry in current to rotor. Brushes wear out, limiting useful life. Requires no electronics to run. Power output is limited by the heat buildup from ohmic loss in the rotor - heat can only escape through the air or the brushes. This means these motors use a lot of heavy copper in the windings, making them large and heavy.

DC brushless motors (Jetboots): Basically an inverted DC motor - windings on the outside, magnets in the rotor - no brushes. Requires complex control electronics. Since the wires are on the outside they are easy to heatsink. This allows you to pass much more current into a smaller motor. No brush friction = higher efficiency.

Superconducting motors (ships): Small, dense, efficient. Requires cryogenic cooling to 77K. Currently extremely expensize. If room temperature superconductors are ever developed these will be everywhere. Until then they will likely be limited to applications where the size and cost of the cryogenic systems are worth the benefits. This probably means military applications.

As to the Romulan underwater propulsion system Fetch has proposed, rememeber that a miniature black hole emits a lot of hawking radiation, limiting the minimum black hole mass you can carry around (i.e., small black holes explode). This means you'd have to carry something at least as heavy as mount everest around with you. I don't think Halcyon makes a wing large enough to float that... :)

Ben Mazin
President, MST
http://www.jetboots.com/

[Aquamaniac]

hmmmm.....I was sure I put "pipe dreams" in there somewhere.

My point was, and I quote:


Apply that kind of technology to a scooter, and we could have a scooter that is the size of a football, that will run for 12 hours.

Dave Manning
Engineering Manager
Electrical Fiber Systems

www.electricalfibers.com

[Uncle Pug]

Aquamaniac once bubbled...
Apply that kind of technology to a scooter, and we could have a scooter that is the size of a football, that will run for 12 hours.

Wind me up a couple Dave and we'll beta them for you. :D