45. MRH13-11-Nov2013-L - page 89

nonperfed and unclad prototype board. The prototype board
was a little stiffer than other materials, withstood heat (good
when cutting the excess thread from the Tortoise mounting
screws flush), and held the screw thread a bit better than sty-
rene or wood. Installing the Tortoise "top down" had a very
nice low profile, with very little of it exposed to damage while
module transported.
It is imperative that you know the exact location of each
turnout and throwbar actuator hole. Take your time and lay
out your track exactly where it is to be located, and make all
adjustments to angles and track centers ahead of time. It is
MUCH more difficult to adjust this once the foamboard is cut
and switch machine is installed.
Maintenance is
a consideration.
Simply cut the
area around the
Tortoise a little bit
larger than neces-
sary to give room
for a screwdriver
to reach the ful-
crum and mount-
ing screws. If the
Tortoise needs
to be replaced,
unscrew the four
2-56 mounting
screws and the
Tortoise drops
from the board.
2: A Tortoise switch machine is
attached to a piece of perfboard with
2-56 screws and dropped into place.
Switch machines on foam - 2
Why single sided copper clad PCB initially?
Initially we planned to use the bottom of the PCB (copper
exposed surface down-top of Tortoise) as a way to help reduce
the number of feeder wires one would have to run to a turn-
out. We were using BK Enterprise turnouts with PCB ties.
Instead of six separate feeder wires for the two points/closure
rails and two stock rails, and two more for the Tortoise SPDT
contacts to flip frog polarity. We were to isolate the copper
clad into two halves down the middle of the board, drill holes
where the rail was to run (through the PCB ties) and run short
feeders, soldering the bottom of the feeder to the copper clad
and then thread the feeder up through the PCB tie right next to
3: Screw excess trimmed with a cutoff disc in a
motor tool.
MRH-Nov 2013
1...,79,80,81,82,83,84,85,86,87,88 90,91,92,93,94,95,96,97,98,99,...143
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