Construction of Full Cylinder, Dual Dielectric e-field Thruster 1 - Outer electrode

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October 12, 2003 - Test construction of rounded outer electrode end

Objective was to find a method of making the rounded ends for the outer electrode tube. The desired side profile as drawn by Zoltan Losonc is as follows:

Diagram for ends of outer electrode for the electric field
      thruster.

Specifically it is the grey cutaway circle drawn just above where 'a' and 'b' are pointing to. The idea is to eliminate the sharp ending of the outer electrode tube. 'a' and 'b' are pointing to where thick resin will be poured in order to produce a smooth, well rounded meeting of the end of the electrode and the circle (tube) represented by the grey circle.

The vinyl tube used. This will be the small grey circle in Zoltan's drawing above.
The vinyl tube to be used for the outer electrode for the 
      electric field thruster.
Original Krazy Glue turned out to be perfect for holding the two ends of the vinyl tube together. It is very hard to pull apart.
Original Krazy Glue used for the electric field
      thruster.
Inside view of the vinyl tube in place with resin already hardened onto it. Note that since it's really a test and learning experience, it's a little bit sloppy.
Resin hardened on the outer electrode for the electric field
      thruster.
Side view of the vinyl tube in place.
Side view of the resin hardened on the outer electrode for 
      the electric field thruster.
Inside view of the vinyl tube after painting with the conductive nickel paint.
Inside view of the vinyl tube after sanding and painting.
Side view of the vinyl tube after painting.
Side view of the vinyl tube after sanding and painting.
The nickel paint used: Super Shield Conductive Nickel Coating from M.G. Chemicals.
The nickel Super Shield Conductive Nickel Coating from M.G.
      Chemicals used on the outer electrode for 
      the electric field thruster.

October 13-17, 2003 - Wax test, putting tubes, wire on outer electrode and nickel painting

Following on the above October 12 tests, I put the test piece in 80 degree C wax and let the wax harden. The idea was to test if the air in the vinyl tube expanded strongly enough to deform the tube. It did not, as the picture below shows.

Wax on the vinyl tube after letting it harden as a heat test.

Having past the tests, I next had to attach the vinyl tubes to the real outer electrode tube.

The "fume hood" for letting the resin harden inside.
The fume hood for letting the resing harden for making the
      outer electrode for the electric field thruster.
A wax plug was put in the middle so that the resin would not drip much into the outer tube. Also, the wax plug is easy to remove. The resin has already been poured. Notice that the vinyl tube has blue wires inside it. This is to reduce the amount of air in the tube. The wax test mentioned above proved this to be unnecessary but I didn't complete that test until the wires were already in place.
A paraffin wax plug is inserted in the cylinder while the
      resin hardens on the vinyl tube.
The end result after sanding.
The resin coated vinyl tube after sanding.
Another view of the end result.
The resin coated vinyl tube after sanding.
The two end tubes attached.
The tube end tubes attached for the electric field thruster.
To attach the wire, at Zoltan's suggetion I removed the insulation from enough wire so that I could wrap the wire around the tube, twist it tightly against the tube and then solder the twist. Naturally I first sanded the insulation off of the tube before putting the wire on. I then put resin on it so that the paraffin wax would not get under it and potentially make it lose contact with the tube.
The wire attached to the outer electrode for 
      the electric field thruster.
The outer electrode with the wire.
The wide attached to the outer electrode for 
      the electric field thruster.
The outer electrode fully painted with the conductive nickel paint. Notice that the entire outer electrode has been painted. It turned out that the outside of the aluminum tube (but not the inside) was coated with something nonconductive. Rather than make a mess sanding it off, I decided to simply paint over it. This wasn't really necessary since the outside will be ground and the field will be very weak on the outside but I did it anyway.
The outer electrode fully painted for 
      the electric field thruster.
View of one of the ends.
One end of the completed outer electrode for 
      the electric field thruster.
Another view.
The other end of the completed outer electrode for 
      the electric field thruster.

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