Here are pictures of the final product which works exactly as I had hoped.
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| The whole structure with gates in the closed position. |
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| The whole structure with gates in the open position. |
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| Closeup of the two linkages between the two levels (one on each side) - note the turnbuckles for fine adjustments. Each deck is made of 1/2 inch plywood with 3/4 inch angle aluminium braces down both sides which eliminate any possibility of sagging over time and provide a very robust surface on which to mount the linkages. |
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| This is the threshold that connects the uprights on both sides. |
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| One side of the threshold is hinged to reveal wiring that must transit from one side to the other. |
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| This turnbuckle is used to ensure that the upright can be slightly adjusted from side to side in the event that the gates become a little too tight or too loose a fit between the two uprights. |
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| A close up of the Lee Valley dampers. |
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| One of the 4 Tortoise switch machines used to operate the safety barriers, mounted in position under the benchwork. The white styrene tube that is epoxied to the final drive shaft of the Tortoise is visible as is the glob of epoxy which oozed out the sides - not pretty but it works very well. |
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| This is a 3D printed shell that covers this one Tortoise - because the Tortoise is mounted underneath a trestle I didn't want the green Tortoise to stand out. I shall add some wood siding to cover the ugly wiring. |
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| One of the barriers in the closed position (since the upper deck is a single track the barrier swings from one side and not from the center as depicted in an earlier graphic). Note the two red LEDs which are glowing as a reminder that the gates are open. I know it is very obvious that the gates are open but the red lights tend to catch the eye while the raised gates send to blend in with the benchwork. |
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| One of the barriers in the closed position. I will be building a finished wood structure to enclose the ugly wire, etc. underneath the LED. |
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| These are the 4 microswitches that control the tortoise, the track power and the lights. Two of these are wired together as double-pole double-throw switches to provide reversible power to the 4 Tortoise switch machine barrier controllers. One provides track power. One provides power to the red LED warning lights. These are mounted in a 3D printed block which is mounted under the benchwork as shown. When the gate is lowered there is another 3D printed block that presses against the 4 microswitches simultaneously. This is shown in the following two diagrams. |
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| The microswitches are pressed by the closing of the lower gate (gate is turquoise). Microswitches (4 of them side by side) are blue and the switch arm is yellow. Note this is not to scale - dimensions are exaggerated to illustrate how the mechanism works. |
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| When the lower gate is open (turquoise) the microswitches are released. |
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| Another shot of the completed structure. |