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View Full Version : This is interesting !


goingbush
11th March 2019, 09:21 AM
YouTube (https://youtu.be/owQEDPKCV4Y)
JDNSW
11th March 2019, 12:26 PM
No, it is not interesting - it is fascinating!
goingbush
11th March 2019, 01:42 PM
Just bought some magnets & bare copper wire on eBay , Need to try this for myself !!
JDNSW
11th March 2019, 02:48 PM
It would probably work on copper pipe - but not as well. Also be interesting to compare different wire diameters.
goingbush
11th March 2019, 03:53 PM
It would probably work on copper pipe - but not as well. Also be interesting to compare different wire diameters.

I dont think so, I think the coil of wire around the battery is energised by contact with -ve & +ve via the magnets & the battery effectively becomes a solenoid slug .

It will be interesting to energise the entire coil length with a bit more oomph & see if the 'slug' gains any useful velocity. I wonder if this is how a rail gun works ? .
JDNSW
11th March 2019, 06:58 PM
The coils of wire are touching, so I'm not too sure just how different it is. In theory you are right - with a pipe the magnetic field and the current would be parallel, but I suspect the current would not neatly flow direct from one end of the battery to the other.

Not exactly a railgun. See Railgun - Wikipedia (https://en.wikipedia.org/wiki/Railgun)
Aaron IIA
11th March 2019, 08:39 PM
It would appear to me, that in the main, the coils are not touching. The ends may be touching where they are under the tape, but the rest is slightly apart. You can see him slightly stretch it when he applies the tape.

Aaron
Ferret
11th March 2019, 09:58 PM
Linear electric motor explained.


https://www.youtube.com/watch?v=CZbXaNWGAkM
speleomike
12th March 2019, 07:33 AM
Hi

Each magnet at the end makes contact with a battery terminal and the copper wire. The battery then delivers quite a current as it is effectively shorted by a dozen loops of wire. Two wires carrying current in the same direction attract each other so the coil will contract around the battery, but due to the frictional drag of the battery the wire coils behind the battery will be dragged with the battery so will be stretched apart. Thats why its taped with sticky tape to the surface, to keep that end in place. Hence the coil mechanically behaves like a snake moves, some bits moving forward, other bits moving back. But as its fixed to the surface at the ends that mechanical movement along the coils is what actually propells the battery along, inside the coil. It is quite neat.

Mike