Tuesday, 19 November 2013

Turnout Operation

I've recently been working on motorising the turnouts. Here is a short video of the first one in action:
video

Below is a side view of the trackbed. The turnout is operated by a servo motor mounted by screws onto a simple wooden frame. If you look carefully, you can see the operating linkage made from brass wire. I coiled it to give it extra spring length to protect against any inadvertent over-throw by the servo. The multicoloured wires from the servo simply plug directly into the ESU SwitchPilot Servo unit, which attaches to the main DCC bus and will control all four turnouts. Since the layout is small, I'm just powering this from the main track supply.

The last view is taken from underneath (with the baseboard upside down!). You can see the functional plastruct tie-bar, as well as the microswitch installed to change the crossing polarity. This is operated by a 12BA bolt through the tie-bar. The SwitchPilot Servo unit has some "programming" buttons which make it easy to set the start and end positions of the servo movement, as well as the movement speed. The turnout is changed via the "accy" button on my DCC handset. If I get fed up of the couple of key presses that are required, the SwitchPilot unit has a band of extra terminals allowing push-switches to be wired in for each turnout.

Monday, 12 August 2013

Track 3

An update with some recent photos (of limited quality). I've just finished tracklaying on the scenic board, although testing and tweaking is still in progress.
The photo below gives an idea of the underside of the board. Dropper wires from each section of rail have been attached, but I've yet to connect all of these up. I've also installed functional tie-bars beneath each of the four turnouts. These still need to have servo motors attached - some experimenting is necessary with springing and microswitches.
Close up of one of the functional tie-bars on the workbench:
These essentially follow Geoff Jones' design in the Track book. The blades themselves are attached to cut down 12BA bolts which sit in the tubes you see here.


Wednesday, 3 April 2013

Track 2

Work in progress on the first turnout. The crossing was constructed separately in the Easitrac jig. Attaching all of the interlaced sleepers and wires in the correct order requires concentration. The plastic sleepers are still loose and not in their final positions. I'm thinking it will help with the other other stock rail and switch to leave the sleepers loose at this stage - in particular, it will allow me to clear a bit of space to solder the dropper wires. I'm attaching two droppers to each piece of rail as I go along - you can see some of these wires poking out from beneath the board.


Before laying the track I drilled/filed holes through the baseboard for the turnout operation. It's hard to see but I've attached a cut-down 12BA bolt to the switch blade, as recommended by Geoff Jones. This will sit in a brass tube and operate the turnout via a functional tie-bar beneath the trackbed. The current plan is to operate these from DCC via servos.


Sunday, 20 January 2013

Track

At long last I've started tracklaying. Here are a few progress shots.

1. I'm using a mixture of Easitrac and PCB sleepers. So far I've glued down the PCB sleepers on the printed Templot plan. Essentially I'm following Jim Watt's practice of PCB sleepers for the switches and crossing areas, with Easitrac everywhere else. With the interlaced timbering, most of the sleepers are ordinary length. The reason for this hybrid approach is that I'm worried about the flimsiness of all-plastic points in this scale, and also the inability to make easy adjustments.

2. Close-up showing one turnout where I've used more PCB sleepers owing to the interlaced catch points (I wanted my sidings to hold as many wagons as possible!). You can see that I've started adding etched chairplates.

3. On the PCB sleepers I'm using Versaline chair plates (and will eventually use the accompanying whitemetal cosmetic chairs). Following advice in the track book I'm pre-tinning these on both sides. I used solder paint which makes this job simple. Owing to the non-standard sleeper arrangement, I'm not using the Versaline jig, just locating the chairplates by eye. I'm also not using them at their intended locations.