North switch machine

Andrew came over last night, and together we had a productive evening, installing the switch machine for the north switch and laying out the staging yard. But that’s another blog post.

FastTracks expedited a spring to finish the last Bullfrog, and so, we were away to the races. Thank-you FastTracks, I was delighted by your customer service. The first step in installing the switch machine, after building it, was to trim the throw wire back so that a little over an inch was showing (1.094″). This brings it flush with the bottom of the ties; we then trimmed it a little further so that it wasn’t pushing on the switch rod assembly at all.


Next is the step when it really helps to have two people: I watched from above while Andrew held it from below and toggled the switch back and forth. Finally, he screwed it home; here he is demonstrating why we installed as many switch machines as we could before the layout was fixed down permanently.


At least he was wearing jeans. I am still picking pieces of swarf out of my knees.

Next, I measured eight feet from the centerline of the track, and drilled a 3/32″ hole for the bearing shaft for the switch stand. Then I sank the 3/32″ tube down the hole. This tube is long enough that its lower end is about even with the bottom of the Bullfrog.


The switch stand target will be held in a tube that fits inside a 1/16″ L-shaped tube that provides the drive.


To drive the target, we created an extension arm for the control rod. One end of the extension rod is a slot so the target tube can rotate inside. The other slips over the end of the 2-56-threaded control rod end. The threads on the control rod end enable it to hold onto the control rod itself (the short end) and adjust the travel of the target (the long end).


We threaded the control rod end through the drive hole on the Bullfrog, and fixed it in place with a nut. Then two nuts, one on either side of the extension rod, enable us to tune and lock the control rod extension. If the target is moving more than 90 degrees, we move the extension away from the pivot point. If it is moving less than 90 degrees, we move it toward the pivot point.


We threaded the yellow control rod through the hole in the side of the Bullfrog and onto its end. Then we added the red outer tube, and plugged that into a block that Andrew had screwed in 3 inches from the fascia. Finally, we wired up the frog to the micro switch and we were done.


The turnout is operationally complete at this point. And that is what I intend to do: run it for a while and ensure there are no bugs. Then I will come back with details and more ballast to finish it off.

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