Floating hooverboard on conductiove surface:
- posted
9 years ago
Floating hooverboard on conductiove surface:
On Fri, 21 Nov 2014 20:22:38 GMT, Jan Panteltje Gave us:
Damn! Jan actually made a cool post.
They should have called it "The Repellor" With fire breathing dragon heads on each end, blowing the "hover flame" imagery.
Eddy currents. The telling detail is that it works over conductive, non- ferrous surfaces.
-- Tim Wescott Wescott Design Services
Just like every skateboard park!
-- John Larkin Highland Technology, Inc picosecond timing precision measurement
On Fri, 21 Nov 2014 14:35:32 -0600, Tim Wescott Gave us:
I thought it would sound more revealing if you said it in the other order, giving the "non-ferrous" clue first, allowing the reader to think immediately "OK, so not a magnetic field effect...", and then "conductive" would prompt their brain into thinking... "Hmmmm, what force can be applied here from a distance that is not a magnetic field?
Kind of weird. Sort of like how a single layer of hex arrayed graphene can stop Helium atoms from crossing, even though the "holes" in the web of graphene are hundreds of times larger than the Helium atoms are.
If we can get it to push against air and even 'space', we have a propulsion system!
Sounds like some coils, and maybe some field-shaping ferrites, and a whole lot of AC current. Makes eddy-current repulsion from the copper sheet on the floor.
How would you steer it? It doesn't track, and there's no obvious way to apply directional forces. Sounds goofy.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement
From the video it seems to want to spin in a clockwise direction. Coriolis effect?
Cheers
To-
I was going to say "you can't", but if you had enough coils you could probably turn and go forward by induction. You'd have to measure the tilt of the board (probably) with an accelerometer and use that for the steering command -- but it could be done.
I have no clue if they actually _do_ it. Somehow I don't think it's going to catch on -- how many towns have copper-sheathed sidewalks?
-- Tim Wescott Wescott Design Services
In the video, pro boarders seem to mostly fall off.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement
On Fri, 21 Nov 2014 17:49:49 -0600, Tim Wescott Gave us:
"Hover vents" was an idea I had for sidewalks or streets, and little magic carpets to ride.
Same braking and steering problem though.
I used to blow sheets of paper across my desk, and liked how they floated on the boundary layer after they got their initial loft.
I still think there are applications for fixed pressure source transit systems. Not for people.
For that, we use maglev and spool the thing up to over 400 mph! brakes and steering?! That's what tracks are for. (and skid pads).
Add "steering" AC coils; adjust their force(s).
They would have to apply sideways force to the copper sheet somehow.
-- John Larkin Highland Technology, Inc picosecond timing laser drivers and controllers
On Fri, 21 Nov 2014 20:23:22 -0800, Robert Baer Gave us:
"These are not the fields you are looking for..."
On Fri, 21 Nov 2014 21:12:04 -0800, John Larkin Gave us:
Kind of like spin on a billiard ball against the felt.
They need "tractor fields" to go with the "hover field".
ineresting thought process [I can't see the original link, blank for over an hour now] from the discussion, sounds like repulsion magnetic fields. Ok, steering? would these 'steering' coils slightly lift one edge more, that would then cause the mobile unit to 'fall' in a direction?
MagLev train info would show a lot of background information on this subject.
On a sunny day (Sat, 22 Nov 2014 07:17:41 -0700) it happened RobertMacy wrote in :
I think it works like this:
I think the hooverboard has some motors that spin disk like this.
I had a Philips LDL1000 video tape recorder that used a dual magnetized disk driving alu disks on the supply and take up reel in normal play, fast forward, and rewind by changing the position of the drive motor, long long time ago:
I thought the rotating was caused by 'unbalance' or a precession, don't care, since not a viable solution if there is a large gap. It's like trying to balance a razor blade on its edge.
I was once involved with a MEMS motor design, a thousand pole stepper motor about 1.25 inch diameter, the two halves, stator and rotor, when put together were thinner than a sheet of paper, and the air gap was designed for 1 micron. mating surface was air bearing. AND the rotor was self centering, again no wear surfaces any place at all!
Ran on something like 3.3Vdc at 25mA to 100mA, can't remember now. Torque could easily peak to almost 2 oz-in. At peak torque the current density through the 'wires' was equivalent to running 100Amps through 36 Awg wire! and could sustain that indefinitely. Why didn't the wires melt? Envision a wire intimately thermally attached to the bottom of a cast iron bathtub. Now run current through that wire and try to melt it. Along that line. As fast as you put heat in, it was removed from the 'wire'.
On a sunny day (Sat, 22 Nov 2014 08:26:44 -0700) it happened RobertMacy wrote in :
What I like if that if you read the text by that youtube video,
The power of youtube! I like it. I just did read the patent, it is exactly like I thought. Magnetics are fun! I have a box full of those smal magnets, something to try maybe one day. Levitation of carbon pencil fillings:
You can do that linear-motor fashion--multiple coils, slightly offset from each other. The fringing fields have horizontal components.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant
One big waffle iron of coils could provide lift and a bit of horizontal force. And horizontal propulsion, a free ride until the batteries die. How about a Tesla skateboard, share the recharging stations?
Doing any actual skateboard tricks would require enormous currents and field strengths.
This crowdsourcing thing is cool. Come up with any zany idea, raise a bunch of money, have fun for a year or so.
-- John Larkin Highland Technology, Inc picosecond timing laser drivers and controllers
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