Tom Grossman's Andromeda part 2 |
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So much for the modifications to the base. The original design had all three light bulbs mounted in deep tubular holders. They
were set back far enough to allow for the clear parts. To fit the LEDs in the bow, I cut the front half off the tubes of the mounting piece.
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To help stabilize the LEDs, small pieces of sheet styrene were glued in the tubes
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I used a Dremel tool to cut away the "bullkheads" in the nacelle parts. New bulkheads for the LEDs were cut to shape
from sheet styrene and glued in place. The interior walls of the nacelles were smoothed by filling with Model Master Red Putty
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The interiors of the nacelles were painted silver. The LEDs were fixed in place with 5-minute epoxy before the nacelles were
assembled
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Holes were cut in the hull for the wires and the nacelles were glued in place
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To fit the LED in the stern, I had to remove the original bulkhead and fashion my own set far enough forward. I started by
setting
an anchor point with a piece of styrene stock on the inside of the hull bottom half for the new bulkhead. I cut a circle from sheet styrene that was about the right size and started trimming it to fit
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More anchor points were added as I went...
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...and the LED was set in place with 5 minute epoxy
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As I learned the hard way, you can fry LEDs with battery current. I was advised by my friend and fellow modeler Scott Longberry
that I could use a
formula to calculate the resistance needed to limit the current. For LEDs in series: resistor in ohms = (voltage of power supply - sum of voltage drops across LEDs) desired current in amps For testing with 2 AA batteries at 20 mA (.02 A): (3v - 1.75v)/0.02 = 62.5ohms. For the 18 V main power off the stand at 20mA: (18v - 16.35v)/0.02 = 82.5ohms. Confused? So was I.
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But it worked. After replacing one or two of the LEDs, I managed to get the whole thing wired up and everything tested
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In the original design, the gun turret posts come through the upper half of the hull and are held in place with caps underneath.
Before gluing the hull halves together, I had to make some sockets for the caps so that I could add the turrets after painting and they would still turn
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I used styrene stock available at most hobby shops. These were glued in place
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Before gluing the hull, I tested everything one more time.
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Once the hull was glued together, the lights stopped working. Not knowing where the problem was, I decided to open the hull
around the socket for the stand.
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I tested everything inside again through my new panel. I did discover a wire that was close to breaking so I soldered it. I
reset the panel by adding more styrene stock to each side of the opening.
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This gave the panel some support. After I have done more assembly, I noticed that my patch job was cracking on one side due to
the stress applied when taking the ship on and off the stand. I cut the crack open wide enough to put another piece of stock in. (PHOTO andr020b)
This was glued in place, trimmed and primered over.
Now, at last, it was just another model.
Onto page three
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